import pg from 'pg'

const { Pool } = pg
export const pool = new Pool({ connectionString: process.env.DATABASE_URL })

export async function initDb() {
  await pool.query(`
    CREATE TABLE IF NOT EXISTS calendars (
      id           SERIAL PRIMARY KEY,
      slug         TEXT NOT NULL UNIQUE,
      name         TEXT NOT NULL,
      color        TEXT NOT NULL,
      is_system    BOOLEAN NOT NULL DEFAULT FALSE,
      deleted_at   TIMESTAMPTZ,
      created_by   TEXT,
      created_at   TIMESTAMPTZ NOT NULL DEFAULT NOW()
    );

    CREATE TABLE IF NOT EXISTS events (
      id              SERIAL PRIMARY KEY,
      calendar_id     INT NOT NULL REFERENCES calendars(id),
      uid             TEXT NOT NULL UNIQUE,   -- iCalendar UID, e.g. '<uuid>@calendar.hotelnumberfour.com'
      title           TEXT NOT NULL,
      description     TEXT,
      location        TEXT,
      start_at        TIMESTAMPTZ NOT NULL,
      end_at          TIMESTAMPTZ NOT NULL,
      all_day         BOOLEAN NOT NULL DEFAULT FALSE,
      sequence        INT NOT NULL DEFAULT 0,
      created_by      TEXT,        -- email
      created_by_name TEXT,
      updated_at      TIMESTAMPTZ NOT NULL DEFAULT NOW(),
      created_at      TIMESTAMPTZ NOT NULL DEFAULT NOW(),
      deleted_at      TIMESTAMPTZ
    );
    CREATE INDEX IF NOT EXISTS events_calendar_idx ON events (calendar_id);
    CREATE INDEX IF NOT EXISTS events_start_idx ON events (start_at);
    CREATE INDEX IF NOT EXISTS events_deleted_idx ON events (deleted_at);

    CREATE TABLE IF NOT EXISTS event_departments (
      event_id        INT NOT NULL REFERENCES events(id) ON DELETE CASCADE,
      department_id   TEXT NOT NULL,
      department_name TEXT NOT NULL,
      PRIMARY KEY (event_id, department_id)
    );

    CREATE TABLE IF NOT EXISTS event_assignees (
      event_id   INT NOT NULL REFERENCES events(id) ON DELETE CASCADE,
      user_email TEXT NOT NULL,
      user_name  TEXT,
      PRIMARY KEY (event_id, user_email)
    );

    CREATE TABLE IF NOT EXISTS event_attachments (
      id           SERIAL PRIMARY KEY,
      event_id     INT NOT NULL REFERENCES events(id) ON DELETE CASCADE,
      filename     TEXT NOT NULL,
      stored_path  TEXT NOT NULL,     -- relative path under uploads dir
      mime_type    TEXT,
      size_bytes   INT,
      uploaded_by  TEXT,              -- email
      created_at   TIMESTAMPTZ NOT NULL DEFAULT NOW()
    );

    CREATE TABLE IF NOT EXISTS caldav_credentials (
      id            SERIAL PRIMARY KEY,
      user_email    TEXT NOT NULL,
      username      TEXT NOT NULL UNIQUE,   -- generated, e.g. '<localpart>-<random6>'
      password_hash TEXT NOT NULL,          -- bcrypt
      label         TEXT,
      created_at    TIMESTAMPTZ NOT NULL DEFAULT NOW(),
      last_used_at  TIMESTAMPTZ
    );

    CREATE TABLE IF NOT EXISTS activity_log (
      id           SERIAL PRIMARY KEY,
      actor_email  TEXT,
      actor_name   TEXT,
      action       TEXT NOT NULL,     -- created | updated | deleted
      entity_type  TEXT NOT NULL,     -- event | calendar | attachment | caldav_credential
      entity_id    INT,
      calendar_id  INT,
      summary      TEXT NOT NULL,
      details      JSONB,
      source       TEXT NOT NULL DEFAULT 'web',  -- web | caldav
      created_at   TIMESTAMPTZ NOT NULL DEFAULT NOW()
    );
    CREATE INDEX IF NOT EXISTS activity_log_calendar_idx ON activity_log (calendar_id, created_at DESC);
    CREATE INDEX IF NOT EXISTS activity_log_entity_idx ON activity_log (entity_type, entity_id);
  `)

  await seedDefaults()
}

async function seedDefaults() {
  await pool.query(
    `INSERT INTO calendars (slug, name, color, is_system)
     VALUES ('bank-holidays', 'Bank Holidays', '#64748b', TRUE)
     ON CONFLICT (slug) DO NOTHING`
  )
  await pool.query(
    `INSERT INTO calendars (slug, name, color, is_system)
     VALUES ('general', 'All Staff', '#c9a84c', FALSE)
     ON CONFLICT (slug) DO NOTHING`
  )
}