CREATE TABLE IF NOT EXISTS comments (
    id TEXT PRIMARY KEY,
    document_id TEXT NOT NULL REFERENCES documents(id) ON DELETE CASCADE,
    version_hash TEXT NOT NULL,
    parent_id TEXT REFERENCES comments(id) ON DELETE CASCADE,
    author_id TEXT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    content TEXT NOT NULL,
    anchor_hash TEXT,
    anchor_line INTEGER,
    created_at TEXT NOT NULL,
    resolved_at TEXT,
    resolved_by TEXT REFERENCES users(id) ON DELETE SET NULL
);

CREATE INDEX IF NOT EXISTS idx_comments_document ON comments(document_id);
CREATE INDEX IF NOT EXISTS idx_comments_parent ON comments(parent_id);
CREATE INDEX IF NOT EXISTS idx_comments_author ON comments(author_id);

CREATE TABLE IF NOT EXISTS notifications (
    id TEXT PRIMARY KEY,
    user_id TEXT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    type TEXT NOT NULL CHECK(type IN ('file_changed', 'comment', 'mention', 'conflict')),
    resource_type TEXT NOT NULL,
    resource_id TEXT NOT NULL,
    message TEXT NOT NULL,
    read_at TEXT,
    emailed_at TEXT,
    created_at TEXT NOT NULL
);

CREATE INDEX IF NOT EXISTS idx_notifications_user ON notifications(user_id);
CREATE INDEX IF NOT EXISTS idx_notifications_unread ON notifications(user_id, read_at) WHERE read_at IS NULL;
CREATE INDEX IF NOT EXISTS idx_notifications_created_at ON notifications(created_at);

CREATE TABLE IF NOT EXISTS watchers (
    user_id TEXT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    document_id TEXT REFERENCES documents(id) ON DELETE CASCADE,
    folder_path TEXT,
    created_at TEXT NOT NULL,
    PRIMARY KEY (user_id, document_id, folder_path)
);

CREATE INDEX IF NOT EXISTS idx_watchers_document ON watchers(document_id);
CREATE INDEX IF NOT EXISTS idx_watchers_folder ON watchers(folder_path);