use crate::search::SearchIndex;
use crate::state::AppState;
use crate::types::*;
use crate::vault::{operations, watcher};
use std::path::Path;
use tauri::{AppHandle, Manager, State};

// ── Vault Management ──

#[tauri::command]
pub fn open_vault(app: AppHandle, state: State<'_, AppState>, path: String) -> Result<(), String> {
    operations::ensure_vault_structure(&path)?;

    // Initialize search index
    let search = SearchIndex::new(&path)?;
    search.rebuild(&path)?;
    *state.search_index.lock().map_err(|e| e.to_string())? = Some(search);

    // Start file watcher
    let w = watcher::start_watcher(app.clone(), path.clone())?;
    *state.watcher.lock().map_err(|e| e.to_string())? = Some(w);

    // Update config
    let mut config = state.config.lock().map_err(|e| e.to_string())?;
    if !config.vaults.iter().any(|v| v.path == path) {
        let name = std::path::Path::new(&path)
            .file_name()
            .unwrap_or_default()
            .to_string_lossy()
            .to_string();
        config.vaults.push(VaultConfig {
            path: path.clone(),
            name,
        });
    }
    config.active_vault = Some(path);
    save_app_config(&config)?;

    Ok(())
}

#[tauri::command]
pub fn get_app_config(state: State<'_, AppState>) -> Result<AppConfig, String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    Ok(config.clone())
}

#[tauri::command]
pub fn set_theme(state: State<'_, AppState>, theme: String) -> Result<(), String> {
    let mut config = state.config.lock().map_err(|e| e.to_string())?;
    config.theme = theme;
    save_app_config(&config)?;
    Ok(())
}

#[tauri::command]
pub fn set_accent_color(state: State<'_, AppState>, color: String) -> Result<(), String> {
    let mut config = state.config.lock().map_err(|e| e.to_string())?;
    config.accent_color = Some(color);
    save_app_config(&config)?;
    Ok(())
}

#[tauri::command]
pub fn set_font_size(state: State<'_, AppState>, size: u32) -> Result<(), String> {
    let mut config = state.config.lock().map_err(|e| e.to_string())?;
    config.font_size = Some(size);
    save_app_config(&config)?;
    Ok(())
}

#[tauri::command]
pub fn set_font_family(state: State<'_, AppState>, family: String) -> Result<(), String> {
    let mut config = state.config.lock().map_err(|e| e.to_string())?;
    config.font_family = Some(family);
    save_app_config(&config)?;
    Ok(())
}

// ── Notebooks ──

#[tauri::command]
pub fn get_notebooks(state: State<'_, AppState>) -> Result<Vec<NotebookEntry>, String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    operations::scan_notebooks(vault_path)
}

#[tauri::command]
pub fn create_notebook(
    state: State<'_, AppState>,
    parent_relative: Option<String>,
    name: String,
) -> Result<NotebookEntry, String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    operations::create_notebook(vault_path, parent_relative.as_deref(), &name)
}

#[tauri::command]
pub fn rename_notebook(path: String, new_name: String) -> Result<String, String> {
    operations::rename_notebook(&path, &new_name)
}

#[tauri::command]
pub fn delete_notebook(state: State<'_, AppState>, path: String) -> Result<(), String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    operations::delete_notebook(vault_path, &path)
}

// ── Notes ──

#[tauri::command]
pub fn get_notes(
    state: State<'_, AppState>,
    notebook_path: Option<String>,
) -> Result<Vec<NoteEntry>, String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    operations::scan_notes(vault_path, notebook_path.as_deref())
}

#[tauri::command]
pub fn read_note(path: String) -> Result<NoteContent, String> {
    operations::read_note(&path)
}

#[tauri::command]
pub fn save_note(
    state: State<'_, AppState>,
    path: String,
    meta: NoteMeta,
    body: String,
) -> Result<(), String> {
    // Snapshot current content before overwriting (if file exists)
    let config = state.config.lock().map_err(|e| e.to_string())?;
    if let Some(vault_path) = &config.active_vault {
        if std::path::Path::new(&path).exists() {
            if let Ok(old_raw) = std::fs::read_to_string(&path) {
                let max_versions = config.max_versions_per_note;
                let note_id = meta.id.clone();
                let vp = vault_path.clone();
                // Snapshot in background so save isn't slowed down
                std::thread::spawn(move || {
                    crate::history::maybe_snapshot(&vp, &note_id, &old_raw, max_versions);
                });
            }
        }
    }
    drop(config);

    operations::save_note(&path, &meta, &body)?;
    Ok(())
}

#[tauri::command]
pub fn create_note(
    state: State<'_, AppState>,
    notebook_relative: Option<String>,
    title: String,
) -> Result<NoteEntry, String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    let entry = operations::create_note(vault_path, notebook_relative.as_deref(), &title)?;

    // Index new note
    if let Ok(search_guard) = state.search_index.lock() {
        if let Some(ref search) = *search_guard {
            let _ = search.index_note(&entry.path);
        }
    }

    Ok(entry)
}

#[tauri::command]
pub fn rename_note(path: String, new_title: String) -> Result<String, String> {
    operations::rename_note(&path, &new_title)
}

#[tauri::command]
pub fn delete_note(state: State<'_, AppState>, path: String) -> Result<(), String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    operations::delete_note(vault_path, &path)?;

    // Remove from index
    if let Ok(search_guard) = state.search_index.lock() {
        if let Some(ref search) = *search_guard {
            let _ = search.remove_note(&path);
        }
    }

    Ok(())
}

#[tauri::command]
pub fn move_note(
    state: State<'_, AppState>,
    note_path: String,
    dest_notebook: String,
) -> Result<String, String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;

    // Compute old relative path before move
    let old_relative = Path::new(&note_path)
        .strip_prefix(vault_path)
        .map(|p| p.to_string_lossy().to_string())
        .unwrap_or_default();

    let new_full_path = operations::move_note(&note_path, &dest_notebook)?;

    // Update quick access if the moved note was in it
    if !old_relative.is_empty() {
        if let Ok(mut qa) = operations::load_quick_access(vault_path) {
            if let Some(pos) = qa.iter().position(|p| *p == old_relative) {
                let new_relative = Path::new(&new_full_path)
                    .strip_prefix(vault_path)
                    .map(|p| p.to_string_lossy().to_string())
                    .unwrap_or_default();
                if !new_relative.is_empty() {
                    qa[pos] = new_relative;
                    let _ = operations::save_quick_access(vault_path, &qa);
                }
            }
        }
    }

    Ok(new_full_path)
}

// ── Tags ──

#[tauri::command]
pub fn get_all_tags(state: State<'_, AppState>) -> Result<Vec<(String, usize)>, String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    operations::get_all_tags(vault_path)
}

// ── Wiki-links ──

#[tauri::command]
pub fn get_all_note_titles(state: State<'_, AppState>) -> Result<Vec<NoteTitleEntry>, String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    let vault = std::path::Path::new(vault_path);
    let mut entries = Vec::new();

    for entry in walkdir::WalkDir::new(vault)
        .into_iter()
        .filter_map(|e| e.ok())
    {
        let path = entry.path();
        if !path.is_file() {
            continue;
        }
        let path_str = path.to_string_lossy();
        if path_str.contains("/.helixnotes/") || path_str.contains("/.trash/") {
            continue;
        }
        if path.extension().and_then(|e| e.to_str()) != Some("md") {
            continue;
        }
        // Read frontmatter title, fallback to filename
        let title = if let Ok(raw) = std::fs::read_to_string(path) {
            crate::vault::frontmatter::extract_title(&raw).unwrap_or_else(|| {
                path.file_stem()
                    .unwrap_or_default()
                    .to_string_lossy()
                    .to_string()
            })
        } else {
            path.file_stem()
                .unwrap_or_default()
                .to_string_lossy()
                .to_string()
        };

        entries.push(NoteTitleEntry {
            title,
            path: path_str.to_string(),
        });
    }

    Ok(entries)
}

// ── Search ──

#[tauri::command]
pub fn search_notes(
    state: State<'_, AppState>,
    query: String,
    limit: Option<usize>,
) -> Result<Vec<SearchResult>, String> {
    let search_guard = state.search_index.lock().map_err(|e| e.to_string())?;
    let search = search_guard
        .as_ref()
        .ok_or("Search index not initialized")?;
    search.search(&query, limit.unwrap_or(20))
}

#[tauri::command]
pub fn reindex(state: State<'_, AppState>) -> Result<(), String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    let search_guard = state.search_index.lock().map_err(|e| e.to_string())?;
    let search = search_guard
        .as_ref()
        .ok_or("Search index not initialized")?;
    search.rebuild(vault_path)
}

// ── Trash ──

#[tauri::command]
pub fn get_trash(state: State<'_, AppState>) -> Result<Vec<NoteEntry>, String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    operations::get_trash_notes(vault_path)
}

#[tauri::command]
pub fn restore_note(
    state: State<'_, AppState>,
    trash_path: String,
    dest_notebook: Option<String>,
) -> Result<String, String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    operations::restore_note(vault_path, &trash_path, dest_notebook.as_deref())
}

#[tauri::command]
pub fn permanent_delete(path: String) -> Result<(), String> {
    operations::permanent_delete(&path)
}

#[tauri::command]
pub fn empty_trash(state: State<'_, AppState>) -> Result<(), String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    operations::empty_trash(vault_path)
}

// ── Vault State ──

#[tauri::command]
pub fn load_vault_state(state: State<'_, AppState>) -> Result<VaultState, String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    operations::load_vault_state(vault_path)
}

#[tauri::command]
pub fn save_vault_state(state: State<'_, AppState>, vault_state: VaultState) -> Result<(), String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    operations::save_vault_state(vault_path, &vault_state)
}

// ── Attachments ──

#[tauri::command]
pub fn save_image(
    state: State<'_, AppState>,
    name: String,
    data: Vec<u8>,
) -> Result<String, String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    operations::save_image(vault_path, &name, &data)
}

#[tauri::command]
pub fn save_attachment(
    state: State<'_, AppState>,
    name: String,
    data: Vec<u8>,
) -> Result<String, String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    operations::save_attachment(vault_path, &name, &data)
}

// ── Notebook Icons ──

#[tauri::command]
pub fn get_notebook_icons(
    state: State<'_, AppState>,
) -> Result<std::collections::HashMap<String, String>, String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    operations::load_notebook_icons(vault_path)
}

#[tauri::command]
pub fn set_notebook_icon(
    state: State<'_, AppState>,
    notebook_relative: String,
    icon_relative: Option<String>,
) -> Result<(), String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    operations::set_notebook_icon(vault_path, &notebook_relative, icon_relative.as_deref())
}

// ── General Settings ──

#[tauri::command]
pub fn set_general_settings(
    state: State<'_, AppState>,
    compact_notes: bool,
    time_format: String,
    gpu_acceleration: bool,
    autostart: bool,
    pdf_preview: bool,
    pdf_height: u32,
    title_mode: String,
    hide_title_in_body: bool,
    default_view_mode: bool,
    show_tray_icon: bool,
    close_to_tray: bool,
    enable_wiki_links: bool,
) -> Result<(), String> {
    let mut config = state.config.lock().map_err(|e| e.to_string())?;
    config.compact_notes = compact_notes;
    config.time_format = time_format;
    config.gpu_acceleration = gpu_acceleration;
    config.autostart = autostart;
    config.pdf_preview = pdf_preview;
    config.pdf_height = pdf_height;
    config.title_mode = title_mode;
    config.hide_title_in_body = hide_title_in_body;
    config.default_view_mode = default_view_mode;
    config.show_tray_icon = show_tray_icon;
    config.close_to_tray = close_to_tray;
    config.enable_wiki_links = enable_wiki_links;
    save_app_config(&config)?;
    Ok(())
}

// ── Quick Access ──

#[tauri::command]
pub fn get_quick_access(state: State<'_, AppState>) -> Result<Vec<NoteEntry>, String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    operations::get_quick_access_notes(vault_path)
}

#[tauri::command]
pub fn add_quick_access(state: State<'_, AppState>, note_relative: String) -> Result<(), String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    operations::add_quick_access(vault_path, &note_relative)
}

#[tauri::command]
pub fn remove_quick_access(
    state: State<'_, AppState>,
    note_relative: String,
) -> Result<(), String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    operations::remove_quick_access(vault_path, &note_relative)
}

#[tauri::command]
pub fn reorder_quick_access(state: State<'_, AppState>, paths: Vec<String>) -> Result<(), String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    operations::save_quick_access(vault_path, &paths)
}

#[tauri::command]
pub fn get_vault_stats(state: State<'_, AppState>) -> Result<VaultStats, String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;

    let mut total_notes: u64 = 0;
    let mut total_attachments: u64 = 0;
    let mut notes_size: u64 = 0;
    let mut attachments_size: u64 = 0;

    for entry in walkdir::WalkDir::new(vault_path)
        .into_iter()
        .filter_map(|e| e.ok())
    {
        let path = entry.path();
        if !path.is_file() {
            continue;
        }
        let path_str = path.to_string_lossy();
        // Include .helixnotes/attachments, skip everything else in .helixnotes
        if path_str.contains("/.helixnotes/") && !path_str.contains("/.helixnotes/attachments/") {
            continue;
        }
        // Skip trash
        if path_str.contains("/.trash/") {
            continue;
        }
        let size = entry.metadata().map(|m| m.len()).unwrap_or(0);
        let ext = path.extension().and_then(|e| e.to_str()).unwrap_or("");
        if ext == "md" {
            total_notes += 1;
            notes_size += size;
        } else {
            total_attachments += 1;
            attachments_size += size;
        }
    }

    Ok(VaultStats {
        total_notes,
        total_attachments,
        notes_size,
        attachments_size,
        total_size: notes_size + attachments_size,
    })
}

#[tauri::command]
pub fn import_obsidian(app: AppHandle) -> Result<(), String> {
    let vault_path = {
        let state = app.state::<AppState>();
        let config = state.config.lock().map_err(|e| e.to_string())?;
        config
            .active_vault
            .clone()
            .ok_or("No active vault".to_string())?
    };
    // Fire-and-forget: return immediately, do work in background thread
    std::thread::spawn(move || {
        use tauri::Emitter;
        match do_import_obsidian(app.clone(), &vault_path) {
            Ok(result) => {
                let _ = app.emit(
                    "import-done",
                    serde_json::json!({
                        "success": true,
                        "files_converted": result.files_converted,
                        "links_converted": result.links_converted,
                    }),
                );
            }
            Err(e) => {
                let _ = app.emit(
                    "import-done",
                    serde_json::json!({
                        "success": false,
                        "error": e,
                    }),
                );
            }
        }
    });
    Ok(())
}

fn do_import_obsidian(app: AppHandle, vault_path: &str) -> Result<ImportResult, String> {
    // Pause file watcher during import
    let state = app.state::<AppState>();
    state
        .importing
        .store(true, std::sync::atomic::Ordering::Relaxed);

    let result = do_import_obsidian_inner(vault_path);

    // Resume file watcher
    state
        .importing
        .store(false, std::sync::atomic::Ordering::Relaxed);

    result
}

fn do_import_obsidian_inner(vault_path: &str) -> Result<ImportResult, String> {
    let vault = std::path::Path::new(vault_path);

    // Build file index: filename -> relative path from vault root
    let mut file_index: std::collections::HashMap<String, String> =
        std::collections::HashMap::new();
    for entry in walkdir::WalkDir::new(vault)
        .into_iter()
        .filter_map(|e| e.ok())
    {
        let path = entry.path();
        if !path.is_file() {
            continue;
        }
        if let Some(name) = path.file_name().and_then(|n| n.to_str()) {
            if let Ok(rel) = path.strip_prefix(vault) {
                file_index.insert(name.to_string(), rel.to_string_lossy().to_string());
            }
        }
    }

    let wiki_embed =
        regex::Regex::new(r"!\[\[([^\]|]+?)(?:\|([^\]]*))?\]\]").map_err(|e| e.to_string())?;
    let wiki_link =
        regex::Regex::new(r"\[\[([^\]|]+?)(?:\|([^\]]*))?\]\]").map_err(|e| e.to_string())?;
    let md_img = regex::Regex::new(r"!\[([^\]]*)\]\(([^)]+)\)").map_err(|e| e.to_string())?;
    let md_link = regex::Regex::new(r"\[([^\]]+)\]\(([^)]+)\)").map_err(|e| e.to_string())?;

    let mut files_converted: u64 = 0;
    let mut links_converted: u64 = 0;

    // Walk all markdown files
    let md_files: Vec<_> = walkdir::WalkDir::new(vault)
        .into_iter()
        .filter_map(|e| e.ok())
        .filter(|e| {
            let p = e.path();
            p.is_file()
                && p.extension().and_then(|x| x.to_str()) == Some("md")
                && !p.to_string_lossy().contains("/.helixnotes/")
                && !p.to_string_lossy().contains("/.trash/")
        })
        .collect();

    for entry in &md_files {
        let path = entry.path();
        let content = match std::fs::read_to_string(path) {
            Ok(c) => c,
            Err(_) => continue,
        };
        let note_dir = path.parent().unwrap_or(std::path::Path::new(""));

        let mut changed = false;
        // Convert embeds first: ![[file.ext]] or ![[file.ext|alt]]
        let after_embeds = wiki_embed
            .replace_all(&content, |caps: &regex::Captures| {
                changed = true;
                links_converted += 1;
                let file_ref = &caps[1];
                let alt = caps.get(2).map(|m| m.as_str()).unwrap_or("");
                let resolved = resolve_wiki_ref(&file_index, file_ref);
                // Convert vault-root-relative path to note-relative
                let abs_target = vault.join(&resolved);
                let rel = pathdiff(
                    abs_target.to_str().unwrap_or(""),
                    note_dir.to_str().unwrap_or(""),
                )
                .unwrap_or(resolved);
                let encoded = rel.replace(' ', "%20");
                // Use image syntax only for images/PDFs; regular link for other files
                let ext = std::path::Path::new(file_ref)
                    .extension()
                    .and_then(|e| e.to_str())
                    .unwrap_or("")
                    .to_lowercase();
                let is_embeddable = matches!(
                    ext.as_str(),
                    "png" | "jpg" | "jpeg" | "gif" | "svg" | "webp" | "bmp" | "ico" | "pdf"
                );
                if is_embeddable {
                    format!("![{}]({})", alt, encoded)
                } else {
                    let display = if alt.is_empty() {
                        file_ref.rsplit('/').next().unwrap_or(file_ref)
                    } else {
                        alt
                    };
                    format!("[{}]({})", display, encoded)
                }
            })
            .to_string();

        // Convert wiki links: [[note]] or [[note|display]]
        let after_links = wiki_link
            .replace_all(&after_embeds, |caps: &regex::Captures| {
                changed = true;
                links_converted += 1;
                let note_ref = &caps[1];
                let display = caps.get(2).map(|m| m.as_str()).unwrap_or(note_ref);
                let resolved = resolve_wiki_ref(&file_index, note_ref);
                // Convert vault-root-relative path to note-relative
                let abs_target = vault.join(&resolved);
                let rel = pathdiff(
                    abs_target.to_str().unwrap_or(""),
                    note_dir.to_str().unwrap_or(""),
                )
                .unwrap_or(resolved);
                let encoded = rel.replace(' ', "%20");
                format!("[{}]({})", display, encoded)
            })
            .to_string();

        // Fix bare-filename standard markdown references: ![alt](filename.ext) where filename has no path separator

        let after_img_fix = md_img
            .replace_all(&after_links, |caps: &regex::Captures| {
                let alt = &caps[1];
                let src = &caps[2];
                let decoded = percent_decode(src);
                // Skip URLs and absolute paths
                if decoded.starts_with("http") || decoded.starts_with('/') {
                    return format!("![{}]({})", alt, src);
                }
                // Try to resolve bare filename via file index
                if !decoded.contains('/') {
                    if let Some(rel) = file_index.get(&decoded) {
                        changed = true;
                        links_converted += 1;
                        let abs_target = vault.join(rel);
                        let note_rel = pathdiff(
                            abs_target.to_str().unwrap_or(""),
                            note_dir.to_str().unwrap_or(""),
                        )
                        .unwrap_or(rel.clone());
                        let encoded = note_rel.replace(' ', "%20");
                        return format!("![{}]({})", alt, encoded);
                    }
                }
                // Fix vault-root-relative paths: if the path resolves from vault root, make it note-relative
                if decoded.contains('/') {
                    let vault_abs = vault.join(&decoded);
                    if vault_abs.exists() {
                        let note_rel = pathdiff(
                            vault_abs.to_str().unwrap_or(""),
                            note_dir.to_str().unwrap_or(""),
                        )
                        .unwrap_or(decoded.clone());
                        if note_rel != decoded {
                            changed = true;
                            links_converted += 1;
                            let encoded = note_rel.replace(' ', "%20");
                            return format!("![{}]({})", alt, encoded);
                        }
                    }
                }
                format!("![{}]({})", alt, src)
            })
            .to_string();

        let after_link_fix = md_link
            .replace_all(&after_img_fix, |caps: &regex::Captures| {
                let display = &caps[1];
                let href = &caps[2];
                let decoded = percent_decode(href);
                // Skip URLs and absolute paths
                if decoded.starts_with("http") || decoded.starts_with('/') {
                    return format!("[{}]({})", display, href);
                }
                // Try to resolve bare filename via file index
                if !decoded.contains('/') {
                    if let Some(rel) = file_index.get(&decoded) {
                        changed = true;
                        links_converted += 1;
                        let abs_target = vault.join(rel);
                        let note_rel = pathdiff(
                            abs_target.to_str().unwrap_or(""),
                            note_dir.to_str().unwrap_or(""),
                        )
                        .unwrap_or(rel.clone());
                        let encoded = note_rel.replace(' ', "%20");
                        return format!("[{}]({})", display, encoded);
                    }
                }
                // Fix vault-root-relative paths
                if decoded.contains('/') {
                    let vault_abs = vault.join(&decoded);
                    if vault_abs.exists() {
                        let note_rel = pathdiff(
                            vault_abs.to_str().unwrap_or(""),
                            note_dir.to_str().unwrap_or(""),
                        )
                        .unwrap_or(decoded.clone());
                        if note_rel != decoded {
                            changed = true;
                            links_converted += 1;
                            let encoded = note_rel.replace(' ', "%20");
                            return format!("[{}]({})", display, encoded);
                        }
                    }
                }
                format!("[{}]({})", display, href)
            })
            .to_string();

        if changed {
            let _ = std::fs::write(path, after_link_fix);
            files_converted += 1;
        }
    }

    // ── Phase 2: Move all non-.md files into .helixnotes/attachments/ preserving structure ──
    let attachments_dir = vault.join(".helixnotes").join("attachments");
    let _ = std::fs::create_dir_all(&attachments_dir);

    let attachment_files: Vec<_> = walkdir::WalkDir::new(vault)
        .into_iter()
        .filter_map(|e| e.ok())
        .filter(|e| {
            let p = e.path();
            if !p.is_file() {
                return false;
            }
            if p.extension().and_then(|x| x.to_str()) == Some("md") {
                return false;
            }
            let path_str = p.to_string_lossy();
            !path_str.contains("/.helixnotes/")
                && !path_str.contains("/.obsidian/")
                && !path_str.contains("/.trash/")
                && !path_str.contains("/.stfolder")
                && !path_str.contains("/.claude/")
        })
        .collect();

    // Map: old vault-relative path -> new vault-relative path (preserving structure)
    let mut moved_files: std::collections::HashMap<String, String> =
        std::collections::HashMap::new();

    for entry in &attachment_files {
        let src_path = entry.path();
        let old_rel = match src_path.strip_prefix(vault) {
            Ok(r) => r.to_string_lossy().to_string(),
            Err(_) => continue,
        };

        // Preserve directory structure: ArkHost/Files/img.png -> .helixnotes/attachments/ArkHost/Files/img.png
        let new_rel = format!(".helixnotes/attachments/{}", old_rel);
        let dest_path = vault.join(&new_rel);

        if let Some(parent) = dest_path.parent() {
            let _ = std::fs::create_dir_all(parent);
        }

        if std::fs::rename(src_path, &dest_path).is_ok()
            || std::fs::copy(src_path, &dest_path)
                .and_then(|_| std::fs::remove_file(src_path))
                .is_ok()
        {
            moved_files.insert(old_rel, new_rel);
        }
    }

    // ── Phase 3: Rewrite references in markdown files to point to new locations ──
    // Use regex to only replace inside ![...](...) and [...](...) patterns
    if !moved_files.is_empty() {
        let md_ref = regex::Regex::new(r"(!?\[[^\]]*\])\(([^)]+)\)").map_err(|e| e.to_string())?;

        let md_files_pass2: Vec<_> = walkdir::WalkDir::new(vault)
            .into_iter()
            .filter_map(|e| e.ok())
            .filter(|e| {
                let p = e.path();
                p.is_file()
                    && p.extension().and_then(|x| x.to_str()) == Some("md")
                    && !p.to_string_lossy().contains("/.helixnotes/")
                    && !p.to_string_lossy().contains("/.trash/")
            })
            .collect();

        for entry in &md_files_pass2 {
            let path = entry.path();
            let content = match std::fs::read_to_string(path) {
                Ok(c) => c,
                Err(_) => continue,
            };
            let note_dir = path.parent().unwrap_or(std::path::Path::new(""));
            let mut changed_p3 = false;

            let new_content = md_ref
                .replace_all(&content, |caps: &regex::Captures| {
                    let prefix = &caps[1]; // ![alt] or [text]
                    let href = &caps[2];
                    let decoded_href = percent_decode(href);

                    // Skip URLs
                    if decoded_href.starts_with("http") || decoded_href.starts_with("data:") {
                        return format!("{}({})", prefix, href);
                    }

                    // Resolve the href to a vault-relative path (files already moved, can't use .exists())
                    // Try note-dir-relative first, then vault-root-relative
                    let abs_from_note = note_dir.join(&decoded_href);
                    let rel_from_note = abs_from_note
                        .strip_prefix(vault)
                        .ok()
                        .map(|r| r.to_string_lossy().to_string());
                    let rel_from_vault = decoded_href.clone();

                    // Check note-relative resolution first, then vault-root
                    let old_vault_rel = rel_from_note
                        .as_ref()
                        .filter(|r| moved_files.contains_key(r.as_str()))
                        .cloned()
                        .or_else(|| {
                            if moved_files.contains_key(&rel_from_vault) {
                                Some(rel_from_vault)
                            } else {
                                None
                            }
                        });

                    if let Some(old_rel) = old_vault_rel {
                        if let Some(new_rel) = moved_files.get(&old_rel) {
                            changed_p3 = true;
                            let new_abs = vault.join(new_rel);
                            let new_note_rel = pathdiff(
                                new_abs.to_str().unwrap_or(""),
                                note_dir.to_str().unwrap_or(""),
                            )
                            .unwrap_or(new_rel.clone());
                            let encoded = new_note_rel.replace(' ', "%20");
                            return format!("{}({})", prefix, encoded);
                        }
                    }

                    format!("{}({})", prefix, href)
                })
                .to_string();

            if changed_p3 {
                let _ = std::fs::write(path, new_content);
            }
        }
    }

    // Clean up empty directories left behind after moving files
    cleanup_empty_dirs(vault);

    Ok(ImportResult {
        files_converted,
        links_converted,
    })
}

/// Remove empty directories recursively (bottom-up), skipping .helixnotes and .obsidian
fn cleanup_empty_dirs(root: &std::path::Path) {
    let mut dirs: Vec<_> = walkdir::WalkDir::new(root)
        .into_iter()
        .filter_map(|e| e.ok())
        .filter(|e| e.path().is_dir())
        .map(|e| e.path().to_path_buf())
        .collect();

    // Sort by depth (deepest first) so we clean bottom-up
    dirs.sort_by(|a, b| b.components().count().cmp(&a.components().count()));

    for dir in dirs {
        let dir_str = dir.to_string_lossy();
        if dir_str.contains("/.helixnotes") || dir_str.contains("/.obsidian") || dir == root {
            continue;
        }
        if let Ok(mut entries) = std::fs::read_dir(&dir) {
            if entries.next().is_none() {
                let _ = std::fs::remove_dir(&dir);
            }
        }
    }
}

/// Compute a relative path from `base` to `target`
fn pathdiff(target: &str, base: &str) -> Result<String, ()> {
    let target = std::path::Path::new(target);
    let base = std::path::Path::new(base);

    let target_components: Vec<_> = target.components().collect();
    let base_components: Vec<_> = base.components().collect();

    // Find common prefix length
    let common = target_components
        .iter()
        .zip(base_components.iter())
        .take_while(|(a, b)| a == b)
        .count();

    let mut result = std::path::PathBuf::new();
    // Go up from base to common ancestor
    for _ in common..base_components.len() {
        result.push("..");
    }
    // Go down from common ancestor to target
    for component in &target_components[common..] {
        result.push(component);
    }

    Ok(result.to_string_lossy().to_string())
}

fn percent_decode(s: &str) -> String {
    let mut result = String::with_capacity(s.len());
    let mut chars = s.bytes();
    while let Some(b) = chars.next() {
        if b == b'%' {
            let hi = chars.next();
            let lo = chars.next();
            if let (Some(h), Some(l)) = (hi, lo) {
                if let Ok(byte) = u8::from_str_radix(&format!("{}{}", h as char, l as char), 16) {
                    result.push(byte as char);
                    continue;
                }
            }
            result.push('%');
        } else {
            result.push(b as char);
        }
    }
    result
}

fn resolve_wiki_ref(
    file_index: &std::collections::HashMap<String, String>,
    reference: &str,
) -> String {
    let reference = reference.trim();
    // Direct match by filename
    if let Some(rel) = file_index.get(reference) {
        return rel.clone();
    }
    // Try with .md extension
    let with_md = format!("{}.md", reference);
    if let Some(rel) = file_index.get(&with_md) {
        return rel.clone();
    }
    // Try matching just the filename part (e.g. "folder/note" -> "note.md")
    if let Some(name) = reference.rsplit('/').next() {
        if let Some(rel) = file_index.get(name) {
            return rel.clone();
        }
        let name_md = format!("{}.md", name);
        if let Some(rel) = file_index.get(&name_md) {
            return rel.clone();
        }
    }
    // Fallback: return as-is
    reference.to_string()
}

// ── Open file with system default handler ──

#[tauri::command]
pub fn open_file(path: String) -> Result<(), String> {
    #[cfg(target_os = "linux")]
    {
        std::process::Command::new("xdg-open")
            .arg(&path)
            .spawn()
            .map_err(|e| format!("Failed to open {}: {}", path, e))?;
    }
    #[cfg(target_os = "macos")]
    {
        std::process::Command::new("open")
            .arg(&path)
            .spawn()
            .map_err(|e| format!("Failed to open {}: {}", path, e))?;
    }
    #[cfg(target_os = "windows")]
    {
        std::process::Command::new("cmd")
            .args(["/C", "start", "", &path])
            .spawn()
            .map_err(|e| format!("Failed to open {}: {}", path, e))?;
    }
    Ok(())
}

#[tauri::command]
pub fn copy_file_to(source: String, destination: String) -> Result<(), String> {
    std::fs::copy(&source, &destination).map_err(|e| format!("Failed to copy file: {}", e))?;
    Ok(())
}

// ── Backup ──

#[tauri::command]
pub fn create_backup(app: AppHandle) -> Result<(), String> {
    let (vault_path, backup_dir, include_attachments, max_count) = {
        let state = app.state::<AppState>();
        let config = state.config.lock().map_err(|e| e.to_string())?;
        let vault_path = config.active_vault.clone().ok_or("No active vault")?;
        let backup_dir = crate::backup::get_backup_dir(&config.backup_location)?;
        (
            vault_path,
            backup_dir,
            config.backup_include_attachments,
            config.backup_max_count,
        )
    };

    std::thread::spawn(move || {
        use tauri::Emitter;
        match crate::backup::create_backup(&vault_path, &backup_dir, include_attachments) {
            Ok(entry) => {
                // Update last backup time
                let state = app.state::<AppState>();
                if let Ok(mut config) = state.config.lock() {
                    config.last_backup_time = Some(entry.created.clone());
                    let _ = save_app_config(&config);
                }
                // Cleanup old backups
                let _ = crate::backup::cleanup_old_backups(&backup_dir, max_count);
                let _ = app.emit(
                    "backup-done",
                    serde_json::json!({
                        "success": true,
                        "entry": entry,
                    }),
                );
            }
            Err(e) => {
                let _ = app.emit(
                    "backup-done",
                    serde_json::json!({
                        "success": false,
                        "error": e,
                    }),
                );
            }
        }
    });
    Ok(())
}

#[tauri::command]
pub fn list_backups(state: State<'_, AppState>) -> Result<Vec<BackupEntry>, String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let backup_dir = crate::backup::get_backup_dir(&config.backup_location)?;
    crate::backup::list_backups(&backup_dir)
}

#[tauri::command]
pub fn restore_backup(app: AppHandle, backup_path: String) -> Result<(), String> {
    let vault_path = {
        let state = app.state::<AppState>();
        let config = state.config.lock().map_err(|e| e.to_string())?;
        config.active_vault.clone().ok_or("No active vault")?
    };

    std::thread::spawn(move || {
        use tauri::Emitter;
        match crate::backup::restore_backup(&vault_path, &backup_path) {
            Ok(()) => {
                let _ = app.emit(
                    "restore-done",
                    serde_json::json!({
                        "success": true,
                    }),
                );
            }
            Err(e) => {
                let _ = app.emit(
                    "restore-done",
                    serde_json::json!({
                        "success": false,
                        "error": e,
                    }),
                );
            }
        }
    });
    Ok(())
}

#[tauri::command]
pub fn delete_backup(backup_path: String) -> Result<(), String> {
    crate::backup::delete_backup(&backup_path)
}

#[tauri::command]
pub fn set_backup_settings(
    state: State<'_, AppState>,
    enabled: bool,
    frequency: String,
    max_count: u32,
    location: Option<String>,
    include_attachments: bool,
) -> Result<(), String> {
    let mut config = state.config.lock().map_err(|e| e.to_string())?;
    config.backup_enabled = enabled;
    config.backup_frequency = frequency;
    config.backup_max_count = max_count;
    config.backup_location = location;
    config.backup_include_attachments = include_attachments;
    save_app_config(&config)?;
    Ok(())
}

// ── Version History ──

#[tauri::command]
pub fn get_note_versions(
    state: State<'_, AppState>,
    note_id: String,
) -> Result<Vec<crate::types::VersionEntry>, String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    crate::history::list_versions(vault_path, &note_id)
}

#[tauri::command]
pub fn create_version(
    state: State<'_, AppState>,
    path: String,
    note_id: String,
) -> Result<(), String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    let max_versions = config.max_versions_per_note;
    let raw = std::fs::read_to_string(&path).map_err(|e| e.to_string())?;
    crate::history::force_snapshot(vault_path, &note_id, &raw, max_versions);
    Ok(())
}

#[tauri::command]
pub fn get_note_version_content(
    state: State<'_, AppState>,
    note_id: String,
    timestamp: String,
) -> Result<String, String> {
    let config = state.config.lock().map_err(|e| e.to_string())?;
    let vault_path = config.active_vault.as_ref().ok_or("No active vault")?;
    crate::history::get_version(vault_path, &note_id, &timestamp)
}

// ── AI ──

#[tauri::command]
pub fn set_ai_settings(
    state: State<'_, AppState>,
    provider: Option<String>,
    api_key: Option<String>,
    model: String,
    writing_style: Option<String>,
) -> Result<(), String> {
    let mut config = state.config.lock().map_err(|e| e.to_string())?;
    let key = api_key.filter(|k| !k.is_empty());
    match provider.as_deref() {
        Some("openai") => config.openai_api_key = key,
        _ => config.ai_api_key = key,
    }
    config.ai_provider = provider;
    config.ai_model = model;
    config.ai_writing_style = writing_style.filter(|s| !s.trim().is_empty());
    save_app_config(&config)?;
    Ok(())
}

#[tauri::command]
pub fn test_ai_connection(app: AppHandle) -> Result<(), String> {
    let (provider, api_key, model) = {
        let state = app.state::<AppState>();
        let config = state.config.lock().map_err(|e| e.to_string())?;
        let provider = config
            .ai_provider
            .clone()
            .unwrap_or_else(|| "anthropic".to_string());
        let key = if provider == "openai" {
            config.openai_api_key.clone()
        } else {
            config.ai_api_key.clone()
        }
        .ok_or("No API key configured")?;
        let model = config.ai_model.clone();
        (provider, key, model)
    };

    std::thread::spawn(move || {
        use tauri::Emitter;
        let rt = tokio::runtime::Runtime::new().unwrap();
        let result = rt.block_on(crate::ai::test_connection(&provider, &api_key, &model));
        match result {
            Ok(msg) => {
                let _ = app.emit(
                    "ai-test-result",
                    serde_json::json!({ "success": true, "message": msg }),
                );
            }
            Err(e) => {
                let _ = app.emit(
                    "ai-test-result",
                    serde_json::json!({ "success": false, "error": e }),
                );
            }
        }
    });
    Ok(())
}

#[tauri::command]
pub fn ai_ask(
    app: AppHandle,
    action: String,
    text: String,
    custom_prompt: Option<String>,
    request_id: String,
) -> Result<(), String> {
    let (provider, api_key, model, writing_style) = {
        let state = app.state::<AppState>();
        let config = state.config.lock().map_err(|e| e.to_string())?;
        let provider = config
            .ai_provider
            .clone()
            .unwrap_or_else(|| "anthropic".to_string());
        let key = if provider == "openai" {
            config.openai_api_key.clone()
        } else {
            config.ai_api_key.clone()
        }
        .ok_or("No API key configured. Go to Settings > AI to set up your API key.")?;
        let model = config.ai_model.clone();
        let style = config.ai_writing_style.clone();
        (provider, key, model, style)
    };

    let mut system_prompt = "You are a helpful writing assistant inside a note-taking app called HelixNotes. \
        You help users improve, rewrite, summarize, and transform their text. \
        Return ONLY the resulting text — no explanations, no markdown code fences, no preamble. \
        Preserve the original language of the text unless specifically asked to translate. \
        Preserve any markdown formatting (bold, italic, links, images, tables, etc.) unless the user asks to change it. \
        If the text contains placeholders like __MEDIA_0__, __MEDIA_1__, etc., keep them exactly as they are in their original positions — they represent images and embedded files.".to_string();

    if let Some(ref style) = writing_style {
        system_prompt.push_str(&format!(
            "\n\nThe user's preferred writing style: {}",
            style
        ));
    }

    let user_message = match action.as_str() {
        "improve" => format!("Improve the writing quality of this text while keeping the same meaning and tone:\n\n{}", text),
        "fix_grammar" => format!("Fix all grammar, spelling, and punctuation errors in this text. Keep the original style:\n\n{}", text),
        "shorter" => format!("Make this text more concise while keeping the key points:\n\n{}", text),
        "longer" => format!("Expand this text with more detail while keeping the same style and tone:\n\n{}", text),
        "professional" => format!("Rewrite this text in a professional, formal tone:\n\n{}", text),
        "friendly" => format!("Rewrite this text in a casual, friendly tone:\n\n{}", text),
        "summarize" => format!("Write a brief summary of this text:\n\n{}", text),
        "explain" => format!("Explain this text in simpler terms:\n\n{}", text),
        "translate_en" => format!("Translate this text to English:\n\n{}", text),
        "translate_nl" => format!("Translate this text to Dutch:\n\n{}", text),
        "translate_de" => format!("Translate this text to German:\n\n{}", text),
        "translate_fr" => format!("Translate this text to French:\n\n{}", text),
        "translate_es" => format!("Translate this text to Spanish:\n\n{}", text),
        "custom" => {
            let prompt = custom_prompt.unwrap_or_else(|| "Improve this text".to_string());
            format!("{}\n\n{}", prompt, text)
        }
        _ => format!("Improve this text:\n\n{}", text),
    };

    crate::ai::ai_request(
        app,
        provider,
        api_key,
        model,
        system_prompt,
        user_message,
        request_id,
    );
    Ok(())
}

// ── Helpers ──

fn app_config_path() -> Result<std::path::PathBuf, String> {
    let config_dir = dirs::config_dir().ok_or("Cannot find config directory")?;
    let app_dir = config_dir.join("helixnotes");
    std::fs::create_dir_all(&app_dir).map_err(|e| e.to_string())?;
    Ok(app_dir.join("config.json"))
}

pub fn load_app_config() -> AppConfig {
    app_config_path()
        .ok()
        .and_then(|p| std::fs::read_to_string(p).ok())
        .and_then(|s| serde_json::from_str(&s).ok())
        .unwrap_or_default()
}

fn save_app_config(config: &AppConfig) -> Result<(), String> {
    let path = app_config_path()?;
    let data = serde_json::to_string_pretty(config).map_err(|e| e.to_string())?;
    std::fs::write(path, data).map_err(|e| e.to_string())?;
    Ok(())
}

// ── Install Type Detection ──

#[tauri::command]
pub fn get_install_type() -> String {
    if cfg!(target_os = "windows") {
        "windows".to_string()
    } else if std::env::var("APPIMAGE").is_ok() {
        "appimage".to_string()
    } else if std::path::Path::new("/var/lib/dpkg/info/helix-notes.list").exists() {
        "deb".to_string()
    } else {
        "native".to_string()
    }
}