CREATE TABLE IF NOT EXISTS users (
    id TEXT PRIMARY KEY NOT NULL,
    username TEXT UNIQUE NOT NULL,
    display_name TEXT NOT NULL,
    role TEXT NOT NULL CHECK (role IN ('ape', 'agent')),
    password_hash TEXT,
    created_at TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ', 'now'))
);

CREATE TABLE IF NOT EXISTS api_tokens (
    id TEXT PRIMARY KEY NOT NULL,
    user_id TEXT NOT NULL REFERENCES users(id),
    token_hash TEXT UNIQUE NOT NULL,
    token_prefix TEXT NOT NULL,
    name TEXT NOT NULL,
    created_at TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ', 'now'))
);

CREATE TABLE IF NOT EXISTS channels (
    id TEXT PRIMARY KEY NOT NULL,
    name TEXT UNIQUE NOT NULL,
    description TEXT NOT NULL DEFAULT '',
    created_by TEXT NOT NULL REFERENCES users(id),
    created_at TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ', 'now'))
);

CREATE TABLE IF NOT EXISTS messages (
    id TEXT PRIMARY KEY NOT NULL,
    seq INTEGER NOT NULL,
    channel_id TEXT NOT NULL REFERENCES channels(id),
    user_id TEXT NOT NULL REFERENCES users(id),
    type TEXT NOT NULL CHECK (type IN ('text', 'code', 'result', 'error', 'plan')),
    content TEXT NOT NULL,
    metadata TEXT,
    reply_to TEXT REFERENCES messages(id),
    created_at TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ', 'now')),
    updated_at TEXT,
    deleted_at TEXT
);

CREATE INDEX IF NOT EXISTS idx_messages_channel ON messages(channel_id, seq);
CREATE INDEX IF NOT EXISTS idx_messages_created ON messages(channel_id, created_at);

-- Auto-increment seq per channel using a trigger
CREATE TABLE IF NOT EXISTS channel_seq (
    channel_id TEXT PRIMARY KEY NOT NULL REFERENCES channels(id),
    next_seq INTEGER NOT NULL DEFAULT 1
);

CREATE TRIGGER IF NOT EXISTS trg_message_seq
AFTER INSERT ON messages
BEGIN
    INSERT INTO channel_seq (channel_id, next_seq) VALUES (NEW.channel_id, 2)
    ON CONFLICT(channel_id) DO UPDATE SET next_seq = next_seq + 1;
END;

-- Enforce reply_to same-channel constraint
CREATE TRIGGER IF NOT EXISTS trg_reply_same_channel
BEFORE INSERT ON messages
WHEN NEW.reply_to IS NOT NULL
BEGIN
    SELECT RAISE(ABORT, 'reply_to must reference a message in the same channel')
    WHERE (SELECT channel_id FROM messages WHERE id = NEW.reply_to) != NEW.channel_id;
END;

-- Seed user for development (no auth yet)
INSERT OR IGNORE INTO users (id, username, display_name, role)
VALUES ('00000000-0000-0000-0000-000000000001', 'benji', 'Benji', 'ape');

INSERT OR IGNORE INTO users (id, username, display_name, role)
VALUES ('00000000-0000-0000-0000-000000000002', 'neeraj', 'Neeraj', 'ape');

-- Seed a general channel
INSERT OR IGNORE INTO channels (id, name, description, created_by)
VALUES ('00000000-0000-0000-0000-000000000010', 'general', 'General discussion', '00000000-0000-0000-0000-000000000001');