<?php
/**
 * SQLite 数据库初始化与迁移
 */
if (!defined('FB_ROOT')) { http_response_code(403); exit('forbidden'); }

/** 打开（或创建）数据库连接，单例 */
function fb_db_init($cfg) {
    static $pdo = null;
    if ($pdo instanceof PDO) { return $pdo; }

    $path = (string)$cfg['db_path'];
    $dir  = dirname($path);
    if (!is_dir($dir)) { @mkdir($dir, 0755, true); }

    $fresh = !file_exists($path);

    $pdo = new PDO('sqlite:' . $path, null, null, [
        PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
        PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
    ]);
    $pdo->exec('PRAGMA journal_mode = WAL');
    $pdo->exec('PRAGMA foreign_keys = ON');
    $pdo->exec('PRAGMA busy_timeout = 5000');

    fb_db_migrate($pdo);

    if ($fresh) { @chmod($path, 0640); }
    return $pdo;
}

/** 便捷访问器 */
function fb_db() {
    return fb_db_init(fb_cfg());
}

/** 建表（幂等） */
function fb_db_migrate(PDO $pdo) {
    $pdo->exec(<<<'SQL'
CREATE TABLE IF NOT EXISTS threads (
    id           INTEGER PRIMARY KEY AUTOINCREMENT,
    title        TEXT    NOT NULL,
    body         TEXT    NOT NULL,
    category     TEXT    NOT NULL DEFAULT 'other',
    author_name  TEXT    NOT NULL,
    author_email TEXT    NOT NULL,
    author_phone TEXT,
    status       TEXT    NOT NULL DEFAULT 'open',
    reply_count  INTEGER NOT NULL DEFAULT 0,
    created_at   INTEGER NOT NULL,
    updated_at   INTEGER NOT NULL,
    ip_hash      TEXT
);
SQL
    );
    $pdo->exec('CREATE INDEX IF NOT EXISTS idx_threads_updated ON threads(updated_at DESC)');
    $pdo->exec('CREATE INDEX IF NOT EXISTS idx_threads_cat     ON threads(category)');

    $pdo->exec(<<<'SQL'
CREATE TABLE IF NOT EXISTS replies (
    id           INTEGER PRIMARY KEY AUTOINCREMENT,
    thread_id    INTEGER NOT NULL,
    body         TEXT    NOT NULL,
    author_name  TEXT    NOT NULL,
    author_email TEXT,
    is_admin     INTEGER NOT NULL DEFAULT 0,
    created_at   INTEGER NOT NULL,
    ip_hash      TEXT,
    FOREIGN KEY(thread_id) REFERENCES threads(id) ON DELETE CASCADE
);
SQL
    );
    $pdo->exec('CREATE INDEX IF NOT EXISTS idx_replies_thread ON replies(thread_id, created_at)');

    $pdo->exec(<<<'SQL'
CREATE TABLE IF NOT EXISTS notify_log (
    id         INTEGER PRIMARY KEY AUTOINCREMENT,
    thread_id  INTEGER NOT NULL,
    reply_id   INTEGER NOT NULL,
    to_email   TEXT    NOT NULL,
    created_at INTEGER NOT NULL,
    ok         INTEGER NOT NULL DEFAULT 0,
    tries      INTEGER NOT NULL DEFAULT 0,
    err        TEXT
);
SQL
    );
    $pdo->exec('CREATE INDEX IF NOT EXISTS idx_notify_thread ON notify_log(thread_id, to_email)');

    // 兼容早期建库：确保 notify_log.tries 存在
    $cols = $pdo->query('PRAGMA table_info(notify_log)')->fetchAll();
    $has  = false;
    foreach ($cols as $c) { if (isset($c['name']) && $c['name'] === 'tries') { $has = true; break; } }
    if (!$has) { $pdo->exec('ALTER TABLE notify_log ADD COLUMN tries INTEGER NOT NULL DEFAULT 0'); }

    $pdo->exec(<<<'SQL'
CREATE TABLE IF NOT EXISTS attachments (
    id         INTEGER PRIMARY KEY AUTOINCREMENT,
    thread_id  INTEGER NOT NULL,
    reply_id   INTEGER,
    kind       TEXT    NOT NULL DEFAULT 'image',
    oss_key    TEXT    NOT NULL,
    mime       TEXT,
    size       INTEGER NOT NULL DEFAULT 0,
    width      INTEGER,
    height     INTEGER,
    orig_name  TEXT,
    seq        INTEGER NOT NULL DEFAULT 0,
    created_at INTEGER NOT NULL,
    FOREIGN KEY(thread_id) REFERENCES threads(id) ON DELETE CASCADE,
    FOREIGN KEY(reply_id)  REFERENCES replies(id) ON DELETE CASCADE
);
SQL
    );
    $pdo->exec('CREATE INDEX IF NOT EXISTS idx_att_thread ON attachments(thread_id, seq)');
    $pdo->exec('CREATE INDEX IF NOT EXISTS idx_att_reply  ON attachments(reply_id)');
    $pdo->exec('CREATE INDEX IF NOT EXISTS idx_att_age    ON attachments(created_at)');
    // 代理读取要按对象键反查（media.php 的鉴权），必须有索引否则每次读图都全表扫描
    $pdo->exec('CREATE INDEX IF NOT EXISTS idx_att_key    ON attachments(oss_key)');

    /* ---- 待入库附件 ----
     * 私有桶 + 内网 Endpoint 下，附件一律经 media.php 代理输出，而代理必须鉴权。
     * 但「上传成功」发生在「表单提交入库」之前 —— 前端上传完就要立刻显示缩略图，
     * 此时 attachments 表里还没有这条记录。若只认 attachments 表，缩略图必然 403。
     * 所以上传成功时先在这张表登记一条，media.php 认「已入库 或 本人刚上传的待入库」，
     * 提交表单后由 fb_attach_save() 转正，过期条目由 cron.php 清理。
     */
    $pdo->exec(<<<'SQL'
CREATE TABLE IF NOT EXISTS pending_attachments (
    id         INTEGER PRIMARY KEY AUTOINCREMENT,
    oss_key    TEXT    NOT NULL,
    kind       TEXT    NOT NULL DEFAULT 'image',
    mime       TEXT,
    size       INTEGER NOT NULL DEFAULT 0,
    ip_hash    TEXT,
    created_at INTEGER NOT NULL
);
SQL
    );
    $pdo->exec('CREATE INDEX IF NOT EXISTS idx_patt_key ON pending_attachments(oss_key)');
    $pdo->exec('CREATE INDEX IF NOT EXISTS idx_patt_age ON pending_attachments(created_at)');

    $pdo->exec(<<<'SQL'
CREATE TABLE IF NOT EXISTS rate_limit (
    id         INTEGER PRIMARY KEY AUTOINCREMENT,
    ip_hash    TEXT    NOT NULL,
    action     TEXT    NOT NULL,
    created_at INTEGER NOT NULL
);
SQL
    );
    $pdo->exec('CREATE INDEX IF NOT EXISTS idx_rl ON rate_limit(ip_hash, action, created_at)');

    /* ---- 站点设置（后台可改，覆盖 config.php 的同名项）----
     * 只存「后台允许修改」的键，见 util.php 的 fb_setting_keys()。
     * value 存 JSON，读取时自动还原类型。
     */
    $pdo->exec(<<<'SQL'
CREATE TABLE IF NOT EXISTS settings (
    key        TEXT PRIMARY KEY,
    value      TEXT,
    updated_at INTEGER
);
SQL
    );

    /* ---- 管理员操作日志 ---- */
    $pdo->exec(<<<'SQL'
CREATE TABLE IF NOT EXISTS mod_log (
    id         INTEGER PRIMARY KEY AUTOINCREMENT,
    thread_id  INTEGER,
    action     TEXT    NOT NULL,
    detail     TEXT,
    created_at INTEGER NOT NULL,
    ip_hash    TEXT
);
SQL
    );
    $pdo->exec('CREATE INDEX IF NOT EXISTS idx_modlog_thread ON mod_log(thread_id, created_at DESC)');
    $pdo->exec('CREATE INDEX IF NOT EXISTS idx_modlog_time   ON mod_log(created_at DESC)');

    // ---- 审核（先审后显）----
    // visible：0=待审核/未公开，1=审核通过已公开
    // mod_note：审核说明（关闭时写给提问人的解释，会随邮件发出）
    // moderated_at：审核时间
    $tcols  = $pdo->query('PRAGMA table_info(threads)')->fetchAll();
    $tnames = [];
    foreach ($tcols as $c) { if (isset($c['name'])) { $tnames[(string)$c['name']] = true; } }

    if (!isset($tnames['visible'])) {
        $pdo->exec('ALTER TABLE threads ADD COLUMN visible INTEGER NOT NULL DEFAULT 0');
        // 功能上线前已存在的内容视为"已审核通过"，保持原来的可见性
        $pdo->exec('UPDATE threads SET visible = 1');
    }
    if (!isset($tnames['mod_note'])) {
        $pdo->exec('ALTER TABLE threads ADD COLUMN mod_note TEXT');
    }
    if (!isset($tnames['moderated_at'])) {
        $pdo->exec('ALTER TABLE threads ADD COLUMN moderated_at INTEGER');
    }
    $pdo->exec('CREATE INDEX IF NOT EXISTS idx_threads_visible ON threads(visible, created_at DESC)');
}