// SQLite-Anbindung (better-sqlite3, synchron & schnell) — Schema wird beim Start angelegt
import Database from 'better-sqlite3';
import { mkdirSync } from 'node:fs';
import { dirname, resolve } from 'node:path';
import { config } from './config.js';

const dbFile = resolve(config.dbPath);
mkdirSync(dirname(dbFile), { recursive: true });

export const db = new Database(dbFile);
db.pragma('journal_mode = WAL');

db.exec(`
    CREATE TABLE IF NOT EXISTS commits (
        sha         TEXT PRIMARY KEY,
        repo        TEXT NOT NULL,
        branch      TEXT NOT NULL,
        message     TEXT NOT NULL,
        author_name TEXT,
        author_user TEXT,
        url         TEXT,
        committed_at TEXT NOT NULL,
        received_at  TEXT NOT NULL DEFAULT (datetime('now'))
    );
    CREATE INDEX IF NOT EXISTS idx_commits_repo_time ON commits (repo, committed_at DESC);

    CREATE TABLE IF NOT EXISTS devlogs (
        message_id  TEXT PRIMARY KEY,
        channel_id  TEXT NOT NULL,
        content     TEXT NOT NULL,
        author_name TEXT,
        posted_at   TEXT NOT NULL,
        archived_at TEXT NOT NULL DEFAULT (datetime('now'))
    );
    CREATE INDEX IF NOT EXISTS idx_devlogs_posted ON devlogs (posted_at DESC);
`);

const insertCommit = db.prepare(`
    INSERT OR IGNORE INTO commits (sha, repo, branch, message, author_name, author_user, url, committed_at)
    VALUES (@sha, @repo, @branch, @message, @author_name, @author_user, @url, @committed_at)
`);

/** Commits eines Pushes speichern — bereits bekannte SHAs werden ignoriert. Gibt Anzahl neuer Zeilen zurück. */
export const saveCommits = db.transaction((commits) => {
    let inserted = 0;
    for (const commit of commits) {
        inserted += insertCommit.run(commit).changes;
    }
    return inserted;
});

const insertDevlog = db.prepare(`
    INSERT OR IGNORE INTO devlogs (message_id, channel_id, content, author_name, posted_at)
    VALUES (@message_id, @channel_id, @content, @author_name, @posted_at)
`);

/** Devlog speichern — bereits bekannte Message-IDs werden ignoriert. Gibt true zurück, wenn neu. */
export function saveDevlog(devlog) {
    return insertDevlog.run(devlog).changes > 0;
}

// --- Lese-Queries für die Web-API (Feature 4) ---

const selectDevlogs = db.prepare(`
    SELECT message_id, content, author_name, posted_at
    FROM devlogs ORDER BY posted_at DESC LIMIT ? OFFSET ?
`);
const countDevlogsStmt = db.prepare('SELECT COUNT(*) AS n FROM devlogs');

export function listDevlogs(limit, offset) {
    return { items: selectDevlogs.all(limit, offset), total: countDevlogsStmt.get().n };
}

const selectCommits = db.prepare(`
    SELECT sha, repo, branch, message, author_name, url, committed_at
    FROM commits ORDER BY committed_at DESC LIMIT ? OFFSET ?
`);
const countCommitsStmt = db.prepare('SELECT COUNT(*) AS n FROM commits');

export function listCommits(limit, offset) {
    return { items: selectCommits.all(limit, offset), total: countCommitsStmt.get().n };
}