SET NAMES utf8mb4;

CREATE TABLE IF NOT EXISTS meetings (
  id INT AUTO_INCREMENT PRIMARY KEY,
  uid CHAR(36) NOT NULL UNIQUE,
  title VARCHAR(160) NOT NULL,
  description TEXT NULL,
  starts_at DATETIME NOT NULL,
  ends_at DATETIME NOT NULL,
  all_day TINYINT(1) NOT NULL DEFAULT 0,
  location VARCHAR(255) NULL,
  video_url VARCHAR(2048) NULL,
  project_id INT NULL,
  organizer_id INT NOT NULL,
  reminder_minutes SMALLINT UNSIGNED NULL,
  recurrence_json TEXT NULL,
  sequence_number INT UNSIGNED NOT NULL DEFAULT 0,
  edit_version INT UNSIGNED NOT NULL DEFAULT 1,
  cancelled_at DATETIME NULL,
  created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
  updated_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  INDEX idx_meetings_range (starts_at, ends_at, cancelled_at),
  INDEX idx_meetings_project (project_id, starts_at),
  INDEX idx_meetings_organizer (organizer_id, starts_at),
  CONSTRAINT fk_meetings_project FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE SET NULL,
  CONSTRAINT fk_meetings_organizer FOREIGN KEY (organizer_id) REFERENCES users(id) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE IF NOT EXISTS meeting_participants (
  meeting_id INT NOT NULL,
  user_id INT NOT NULL,
  rsvp ENUM('pending','accepted','declined','tentative') NOT NULL DEFAULT 'pending',
  responded_at DATETIME NULL,
  PRIMARY KEY (meeting_id, user_id),
  INDEX idx_meeting_participants_user (user_id, meeting_id),
  CONSTRAINT fk_mp_meeting FOREIGN KEY (meeting_id) REFERENCES meetings(id) ON DELETE CASCADE,
  CONSTRAINT fk_mp_user FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE IF NOT EXISTS meeting_external_participants (
  meeting_id INT NOT NULL,
  email VARCHAR(160) NOT NULL,
  PRIMARY KEY (meeting_id, email),
  CONSTRAINT fk_mep_meeting FOREIGN KEY (meeting_id) REFERENCES meetings(id) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE IF NOT EXISTS meeting_exceptions (
  meeting_id INT NOT NULL,
  occurrence_start DATETIME NOT NULL,
  created_by INT NULL,
  created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (meeting_id, occurrence_start),
  CONSTRAINT fk_mex_meeting FOREIGN KEY (meeting_id) REFERENCES meetings(id) ON DELETE CASCADE,
  CONSTRAINT fk_mex_user FOREIGN KEY (created_by) REFERENCES users(id) ON DELETE SET NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE IF NOT EXISTS meeting_reminders (
  meeting_id INT NOT NULL,
  occurrence_start DATETIME NOT NULL,
  sent_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (meeting_id, occurrence_start),
  CONSTRAINT fk_mr_meeting FOREIGN KEY (meeting_id) REFERENCES meetings(id) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

ALTER TABLE notifications MODIFY COLUMN entity_type ENUM('project','activity','meeting') NULL;