-- Exam module schema. Execute explicitly as a database deployment step.
CREATE TABLE IF NOT EXISTS exam_question (
  id bigint NOT NULL AUTO_INCREMENT,
  school_id varchar(64) NOT NULL,
  teacher_id varchar(64) NOT NULL,
  question_type varchar(24) NOT NULL,
  stem longtext NOT NULL,
  options_json longtext NULL,
  answer_json longtext NOT NULL,
  answer_analysis longtext NULL,
  attachment_name varchar(255) NULL,
  attachment_url varchar(512) NULL,
  create_time timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  update_time timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (id),
  KEY idx_exam_question_owner (teacher_id, question_type)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE IF NOT EXISTS exam_assessment (
  id bigint NOT NULL AUTO_INCREMENT,
  school_id varchar(64) NOT NULL,
  teacher_id varchar(64) NOT NULL,
  exam_name varchar(20) NOT NULL,
  start_time datetime NOT NULL,
  end_time datetime NOT NULL,
  publication_status varchar(16) NOT NULL DEFAULT 'DRAFT',
  allow_rollback bit NOT NULL DEFAULT 1,
  exported_at datetime NULL,
  create_time timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  update_time timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (id),
  UNIQUE KEY uk_exam_school_name (school_id, exam_name),
  KEY idx_exam_teacher (teacher_id, start_time)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE IF NOT EXISTS exam_assessment_class (
  exam_id bigint NOT NULL,
  teaching_class_id varchar(64) NOT NULL,
  PRIMARY KEY (exam_id, teaching_class_id),
  KEY idx_exam_class (teaching_class_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE IF NOT EXISTS exam_assessment_question (
  exam_id bigint NOT NULL,
  question_id bigint NOT NULL,
  question_order int NOT NULL,
  question_score decimal(7,2) NOT NULL,
  question_type varchar(24) NOT NULL,
  stem longtext NOT NULL,
  options_json longtext NULL,
  answer_json longtext NOT NULL,
  answer_analysis longtext NULL,
  attachment_name varchar(255) NULL,
  attachment_url varchar(512) NULL,
  create_time timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  update_time timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (exam_id, question_id),
  KEY idx_exam_question_order (exam_id, question_order)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE IF NOT EXISTS exam_attempt (
  id bigint NOT NULL AUTO_INCREMENT,
  exam_id bigint NOT NULL,
  student_id varchar(64) NOT NULL,
  teaching_class_id varchar(64) NOT NULL,
  attempt_status varchar(16) NOT NULL DEFAULT 'IN_PROGRESS',
  device_token varchar(128) NOT NULL,
  started_at datetime NOT NULL,
  submitted_at datetime NULL,
  auto_submitted bit NOT NULL DEFAULT 0,
  objective_score decimal(7,2) NOT NULL DEFAULT 0,
  subjective_score decimal(7,2) NOT NULL DEFAULT 0,
  total_score decimal(7,2) NOT NULL DEFAULT 0,
  create_time timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  update_time timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (id),
  UNIQUE KEY uk_exam_student (exam_id, student_id),
  KEY idx_attempt_exam_status (exam_id, attempt_status)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE IF NOT EXISTS exam_attempt_answer (
  attempt_id bigint NOT NULL,
  question_id bigint NOT NULL,
  answer_json longtext NULL,
  answer_file_name varchar(255) NULL,
  answer_file_url varchar(512) NULL,
  is_correct bit NULL,
  awarded_score decimal(7,2) NULL,
  update_time timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (attempt_id, question_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;