//! Tauri commands: the typed IPC surface bridging the web UI to `mtgc-core`.
//!
//! JS passes camelCase argument keys; Tauri maps them to these snake_case params.

use std::path::PathBuf;
use std::sync::Mutex;

use mtgc_core::{
    CardRef, CardSuggestion, Deck, DeckEntry, LibraryCard, LibraryCopy, LibraryFacets,
    LibraryFilter, LibraryStats, PrintingRef, SuggestOptions,
};
use serde::Serialize;
use tauri::{AppHandle, Emitter, State};

use crate::state::AppState;

type Db<'a> = State<'a, Mutex<AppState>>;
type Res<T> = Result<T, String>;

/// High-level status for the top bar / first-run gating.
#[derive(Serialize)]
pub struct Status {
    /// The open library's name and where it syncs: the account and server, or
    /// this device only. Changes whenever another library is opened.
    pub library_label: String,
    /// The open library.
    pub library: OpenLibrary,
    pub reference_path: String,
    pub reference_ready: bool,
    pub card_count: usize,
    /// Unix timestamp (seconds) of reference.db's last modification — i.e.
    /// when "Update card data" last completed. `None` if unavailable.
    pub reference_updated_at: Option<i64>,
    /// Columns this build's card-data schema has that the installed card data
    /// lacks (`"table.column"`). Non-empty means it was built by an older
    /// version and should be updated; empty when current or not loaded.
    pub reference_missing_columns: Vec<String>,
    /// Whether this is a mobile build. The UI uses it to hide affordances that
    /// only make sense with an arbitrary-path filesystem. Reported from the build
    /// target rather than sniffed from the user agent so it can't disagree with
    /// what the backend will actually allow.
    pub is_mobile: bool,
}

#[derive(Serialize)]
pub struct OpenLibrary {
    pub id: String,
    pub name: String,
}

/// The open library and where it syncs, for the top bar — never the internal
/// working database, which is an implementation detail the user never sees.
fn library_label(s: &AppState) -> String {
    let lib = s.active_library();
    match s.sync_account() {
        Some(a) if a.token.is_some() && lib.sync => {
            let host = url::Url::parse(&a.server_url)
                .ok()
                .and_then(|u| u.host_str().map(str::to_string))
                .unwrap_or_else(|| a.server_url.clone());
            format!("{} · {} @ {host}", lib.name, a.user.username)
        }
        _ => format!("{} · this device only", lib.name),
    }
}

fn status_of(s: &AppState) -> Status {
    let reference_updated_at = std::fs::metadata(&s.reference_path)
        .and_then(|m| m.modified())
        .ok()
        .and_then(|t| t.duration_since(std::time::UNIX_EPOCH).ok())
        .map(|d| d.as_secs() as i64);
    let lib = s.active_library();
    Status {
        library_label: library_label(s),
        library: OpenLibrary { id: lib.id.clone(), name: lib.name.clone() },
        reference_path: s.reference_path.display().to_string(),
        reference_ready: s.catalog.is_some(),
        card_count: s.index.as_ref().map(|i| i.len()).unwrap_or(0),
        reference_updated_at,
        reference_missing_columns: s
            .catalog
            .as_ref()
            .map(|c| c.missing_reference_columns().to_vec())
            .unwrap_or_default(),
        is_mobile: cfg!(mobile),
    }
}

#[tauri::command]
pub fn get_status(db: Db) -> Res<Status> {
    let status = status_of(&db.lock().unwrap());
    // Only ever called once per launch (from the frontend's one status-fetch
    // effect, retried on failure/timeout) — cheap to log unconditionally, and
    // it's the one way to tell "this invoke never reached Rust" (nothing
    // logged at all) apart from "it reached Rust and returned not-ready".
    crate::mlog!(
        "get_status: reference_ready={} card_count={}",
        status.reference_ready,
        status.card_count
    );
    Ok(status)
}

/// Download Scryfall bulk data and (re)build reference.db, then reopen.
/// Runs on a blocking thread so the UI stays responsive and progress events flow.
#[tauri::command]
pub async fn update_card_data(app: AppHandle, db: Db<'_>) -> Res<Status> {
    let reference_path = db.lock().unwrap().reference_path.clone();
    let cancel = mtgc_core::ingest::CancelToken::new();
    db.lock().unwrap().ingest_cancel = Some(cancel.clone());
    let app_for_progress = app.clone();

    crate::mlog!("update_card_data: starting ingest into {}", reference_path.display());

    let result = tauri::async_runtime::spawn_blocking({
        let cancel = cancel.clone();
        move || {
            mtgc_core::ingest::build_reference_db(&reference_path, &cancel, |p| {
                let _ = app_for_progress.emit("ingest-progress", p);
            })
        }
    })
    .await
    .map_err(|e| e.to_string())?;

    db.lock().unwrap().ingest_cancel = None;
    let stats = crate::logged("update_card_data", result.map_err(|e| e.to_string()))?;
    crate::mlog!(
        "update_card_data: ok ({} oracle cards, {} printings)",
        stats.oracle_cards,
        stats.printings
    );

    let mut s = db.lock().unwrap();
    crate::logged("update_card_data reopen", s.reopen())?;
    Ok(status_of(&s))
}

/// Adopt an already-built `reference.db` from elsewhere on the device instead of
/// downloading and rebuilding it.
///
/// This is the practical way to provision card data on mobile: the built db is
/// ~73MB, whereas `update_card_data` streams ~740MB of JSON and can take many
/// minutes — and Android may kill the app partway through. Copy the file from a
/// desktop install and point this at it.
#[tauri::command]
pub fn import_reference_db(db: Db, path: String) -> Res<Status> {
    let src = PathBuf::from(&path);
    let mut s = db.lock().unwrap();
    let dest = s.reference_path.clone();

    if src == dest {
        return Err("That file is already the active card database.".into());
    }

    crate::mlog!("import_reference_db: from {}", src.display());

    // Validate before disturbing the working db, so picking the wrong file is a
    // harmless error rather than a broken install.
    let cards = crate::logged(
        "import_reference_db validate",
        mtgc_core::db::inspect_reference_db(&src).map_err(|e| e.to_string()),
    )?;
    crate::mlog!("import_reference_db: source holds {cards} oracle cards");

    // Release the handles on the file we're about to replace.
    s.close();

    // Copy beside the destination, then rename: a same-directory rename is
    // atomic, so an interrupted copy can't leave a half-written reference.db.
    let tmp = dest.with_extension("db.import");
    let install = || -> std::io::Result<()> {
        if let Some(parent) = dest.parent() {
            std::fs::create_dir_all(parent)?;
        }
        std::fs::copy(&src, &tmp)?;
        std::fs::rename(&tmp, &dest)
    };
    if let Err(e) = install() {
        let _ = std::fs::remove_file(&tmp);
        let _ = s.reopen(); // put the previous db back into service
        return Err(format!("Couldn't install that card database: {e}"));
    }

    s.reopen()?;
    Ok(status_of(&s))
}

/// Cancel an in-progress `update_card_data`, if one is running. No-op otherwise.
#[tauri::command]
pub fn cancel_update_card_data(db: Db) -> Res<()> {
    let s = db.lock().unwrap();
    if let Some(c) = &s.ingest_cancel {
        c.cancel();
    }
    Ok(())
}

#[tauri::command]
pub fn search_cards(db: Db, query: String, limit: usize) -> Res<Vec<CardRef>> {
    let s = db.lock().unwrap();
    Ok(s.index()?.search(&query, limit))
}

#[tauri::command]
pub fn add_owned(db: Db, oracle_id: String, delta: i64) -> Res<i64> {
    let s = db.lock().unwrap();
    s.catalog()?.add_owned(&oracle_id, delta).map_err(|e| e.to_string())
}

#[tauri::command]
pub fn set_owned(db: Db, oracle_id: String, quantity: i64) -> Res<i64> {
    let s = db.lock().unwrap();
    s.catalog()?
        .set_owned(&oracle_id, quantity)
        .map_err(|e| e.to_string())
}

#[tauri::command]
pub fn set_location(db: Db, oracle_id: String, location: String) -> Res<()> {
    let s = db.lock().unwrap();
    s.catalog()?
        .set_location(&oracle_id, &location)
        .map_err(|e| e.to_string())
}

#[tauri::command]
pub fn deck_contents(db: Db, deck_id: i64) -> Res<Vec<DeckEntry>> {
    let s = db.lock().unwrap();
    s.catalog()?.deck_contents(deck_id).map_err(|e| e.to_string())
}

#[tauri::command]
pub fn suggest_cards(
    db: Db,
    deck_id: i64,
    offset: i64,
    options: SuggestOptions,
) -> Res<Vec<CardSuggestion>> {
    let s = db.lock().unwrap();
    s.catalog()?
        .suggest_cards(deck_id, 50, offset.max(0) as usize, options)
        .map_err(|e| e.to_string())
}

#[tauri::command]
pub fn search_library(db: Db, filter: LibraryFilter) -> Res<Vec<LibraryCard>> {
    let s = db.lock().unwrap();
    s.catalog()?.search_library(&filter).map_err(|e| e.to_string())
}

#[tauri::command]
pub fn search_reference(db: Db, filter: LibraryFilter, limit: usize) -> Res<Vec<LibraryCard>> {
    let s = db.lock().unwrap();
    s.catalog()?
        .search_reference(&filter, limit)
        .map_err(|e| e.to_string())
}

#[tauri::command]
pub fn get_library_stats(db: Db) -> Res<LibraryStats> {
    let s = db.lock().unwrap();
    s.catalog()?.library_stats().map_err(|e| e.to_string())
}

#[tauri::command]
pub fn get_library_facets(db: Db) -> Res<LibraryFacets> {
    let s = db.lock().unwrap();
    s.catalog()?.library_facets().map_err(|e| e.to_string())
}

#[tauri::command]
pub fn get_reference_facets(db: Db) -> Res<LibraryFacets> {
    let s = db.lock().unwrap();
    s.catalog()?.reference_facets().map_err(|e| e.to_string())
}

#[tauri::command]
pub fn list_decks(db: Db) -> Res<Vec<Deck>> {
    let s = db.lock().unwrap();
    s.catalog()?.list_decks().map_err(|e| e.to_string())
}

#[tauri::command]
pub fn create_deck(db: Db, name: String, commander_oracle_id: Option<String>) -> Res<Deck> {
    let s = db.lock().unwrap();
    s.catalog()?
        .create_deck(&name, commander_oracle_id.as_deref())
        .map_err(|e| e.to_string())
}

#[tauri::command]
pub fn delete_deck(db: Db, deck_id: i64) -> Res<()> {
    let s = db.lock().unwrap();
    s.catalog()?.delete_deck(deck_id).map_err(|e| e.to_string())
}

#[tauri::command]
pub fn rename_deck(db: Db, deck_id: i64, name: String) -> Res<()> {
    let s = db.lock().unwrap();
    s.catalog()?
        .rename_deck(deck_id, &name)
        .map_err(|e| e.to_string())
}

#[tauri::command]
pub fn duplicate_deck(db: Db, deck_id: i64, new_name: String) -> Res<Deck> {
    let s = db.lock().unwrap();
    s.catalog()?
        .duplicate_deck(deck_id, &new_name)
        .map_err(|e| e.to_string())
}

#[tauri::command]
pub fn set_deck_format(db: Db, deck_id: i64, format: String) -> Res<()> {
    let s = db.lock().unwrap();
    s.catalog()?
        .set_deck_format(deck_id, &format)
        .map_err(|e| e.to_string())
}

#[tauri::command]
pub fn set_deck_commander(db: Db, deck_id: i64, oracle_id: Option<String>) -> Res<()> {
    let s = db.lock().unwrap();
    s.catalog()?
        .set_deck_commander(deck_id, oracle_id.as_deref())
        .map_err(|e| e.to_string())
}

#[tauri::command]
pub fn set_deck_card(
    db: Db,
    deck_id: i64,
    oracle_id: String,
    quantity: i64,
    is_commander: bool,
    is_maybeboard: bool,
) -> Res<()> {
    let s = db.lock().unwrap();
    s.catalog()?
        .set_deck_card(deck_id, &oracle_id, quantity, is_commander, is_maybeboard)
        .map_err(|e| e.to_string())
}

#[tauri::command]
pub fn list_printings(db: Db, oracle_id: String) -> Res<Vec<PrintingRef>> {
    let s = db.lock().unwrap();
    s.catalog()?.list_printings(&oracle_id).map_err(|e| e.to_string())
}

#[tauri::command]
pub fn list_library_copies(db: Db, oracle_id: String) -> Res<Vec<LibraryCopy>> {
    let s = db.lock().unwrap();
    s.catalog()?
        .list_library_copies(&oracle_id)
        .map_err(|e| e.to_string())
}

/// Returns the card's owned quantity afterwards, which grows when the copy
/// groups would otherwise exceed it.
#[tauri::command]
pub fn set_library_copy(
    db: Db,
    oracle_id: String,
    scryfall_id: String,
    finish: String,
    quantity: i64,
) -> Res<i64> {
    let s = db.lock().unwrap();
    s.catalog()?
        .set_library_copy(&oracle_id, &scryfall_id, &finish, quantity)
        .map_err(|e| e.to_string())
}

/// Returns the slot afterwards, so the UI can show the resulting art without
/// knowing how the default is chosen.
#[tauri::command]
pub fn set_deck_card_printing(
    db: Db,
    deck_id: i64,
    oracle_id: String,
    scryfall_id: Option<String>,
) -> Res<Option<DeckEntry>> {
    let s = db.lock().unwrap();
    let catalog = s.catalog()?;
    catalog
        .set_deck_card_printing(deck_id, &oracle_id, scryfall_id.as_deref())
        .map_err(|e| e.to_string())?;
    let contents = catalog.deck_contents(deck_id).map_err(|e| e.to_string())?;
    Ok(contents.into_iter().find(|e| e.card.oracle_id == oracle_id))
}

#[tauri::command]
pub fn card_decks(db: Db, oracle_id: String) -> Res<Vec<Deck>> {
    let s = db.lock().unwrap();
    s.catalog()?.card_decks(&oracle_id).map_err(|e| e.to_string())
}

#[derive(Serialize)]
pub struct DeckImportResult {
    pub deck: Deck,
    pub unresolved: Vec<String>,
}

#[derive(Serialize)]
pub struct LibraryImportResult {
    pub added: Vec<(String, i64)>,
    pub unresolved: Vec<String>,
}

#[tauri::command]
pub fn export_deck(db: Db, deck_id: i64, path: String) -> Res<()> {
    let s = db.lock().unwrap();
    let text = s.catalog()?.export_deck_text(deck_id).map_err(|e| e.to_string())?;
    std::fs::write(&path, text).map_err(|e| e.to_string())
}

#[tauri::command]
pub fn import_deck(db: Db, path: String, name: String) -> Res<DeckImportResult> {
    let s = db.lock().unwrap();
    let text = std::fs::read_to_string(&path).map_err(|e| e.to_string())?;
    let (deck, unresolved) = s.catalog()?.import_deck(&name, &text).map_err(|e| e.to_string())?;
    Ok(DeckImportResult { deck, unresolved })
}

#[tauri::command]
pub fn export_library_cards(db: Db, oracle_ids: Vec<String>, path: String) -> Res<()> {
    let s = db.lock().unwrap();
    let text = s
        .catalog()?
        .export_library_text(&oracle_ids)
        .map_err(|e| e.to_string())?;
    std::fs::write(&path, text).map_err(|e| e.to_string())
}

#[tauri::command]
pub fn import_library_cards(db: Db, path: String) -> Res<LibraryImportResult> {
    let s = db.lock().unwrap();
    let text = std::fs::read_to_string(&path).map_err(|e| e.to_string())?;
    let (added, unresolved) = s.catalog()?.import_library_list(&text).map_err(|e| e.to_string())?;
    Ok(LibraryImportResult { added, unresolved })
}