"""数据库表结构 DDL（Sprint 1：users / preferences / ppt_records / versions / chat_messages）。"""

SCHEMA_SQL = """
CREATE TABLE IF NOT EXISTS users (
    id            INTEGER PRIMARY KEY AUTOINCREMENT,
    username      TEXT UNIQUE NOT NULL,
    password_hash TEXT NOT NULL,
    created_at    TEXT NOT NULL DEFAULT (datetime('now', 'localtime'))
);

CREATE TABLE IF NOT EXISTS preferences (
    id                    INTEGER PRIMARY KEY AUTOINCREMENT,
    user_id               INTEGER NOT NULL,
    default_scene         TEXT NOT NULL DEFAULT 'training',
    default_color         TEXT NOT NULL DEFAULT 'blue',
    default_language      TEXT NOT NULL DEFAULT 'zh',
    default_canvas        TEXT NOT NULL DEFAULT 'ppt169',
    default_image_strategy TEXT NOT NULL DEFAULT 'web',
    default_page_min      INTEGER NOT NULL DEFAULT 10,
    default_page_max      INTEGER NOT NULL DEFAULT 15,
    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
);
CREATE UNIQUE INDEX IF NOT EXISTS idx_preferences_user ON preferences(user_id);

CREATE TABLE IF NOT EXISTS ppt_records (
    id                 INTEGER PRIMARY KEY AUTOINCREMENT,
    user_id            INTEGER NOT NULL,
    title              TEXT NOT NULL,
    content            TEXT NOT NULL,
    scene              TEXT NOT NULL,
    language           TEXT NOT NULL DEFAULT 'zh',
    canvas             TEXT NOT NULL DEFAULT 'ppt169',
    image_strategy     TEXT NOT NULL DEFAULT 'web',
    color_scheme       TEXT NOT NULL,
    page_min           INTEGER NOT NULL,
    page_max           INTEGER NOT NULL,
    status             TEXT NOT NULL DEFAULT 'processing',
    file_size          INTEGER,
    page_count         INTEGER,
    generate_duration  INTEGER,
    created_at         TEXT NOT NULL DEFAULT (datetime('now', 'localtime')),
    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
);
CREATE INDEX IF NOT EXISTS idx_records_user_time ON ppt_records(user_id, created_at DESC);
CREATE INDEX IF NOT EXISTS idx_records_user_scene ON ppt_records(user_id, scene);

CREATE TABLE IF NOT EXISTS versions (
    id          INTEGER PRIMARY KEY AUTOINCREMENT,
    record_id   INTEGER NOT NULL,
    version_no  INTEGER NOT NULL,
    file_path   TEXT NOT NULL,
    svg_dir     TEXT,
    change_note TEXT,
    created_at  TEXT NOT NULL DEFAULT (datetime('now', 'localtime')),
    FOREIGN KEY (record_id) REFERENCES ppt_records(id) ON DELETE CASCADE
);
CREATE INDEX IF NOT EXISTS idx_versions_record ON versions(record_id);

CREATE TABLE IF NOT EXISTS chat_messages (
    id         INTEGER PRIMARY KEY AUTOINCREMENT,
    record_id  INTEGER NOT NULL,
    role       TEXT NOT NULL,
    content    TEXT NOT NULL,
    created_at TEXT NOT NULL DEFAULT (datetime('now', 'localtime')),
    FOREIGN KEY (record_id) REFERENCES ppt_records(id) ON DELETE CASCADE
);
CREATE INDEX IF NOT EXISTS idx_chat_record ON chat_messages(record_id, created_at);
"""


def init_db() -> None:
    """执行全部 DDL，幂等可重复调用。"""
    from .conn import get_connection

    conn = get_connection()
    try:
        conn.executescript(SCHEMA_SQL)
        conn.commit()
    finally:
        conn.close()