-- ==============================================================================
-- SAQEL PLATFORM (منصة صَقِل) - ENTERPRISE MULTI-PERSONA DATABASE SCHEMA (MySQL 8.4+)
-- Version: 3.0.0 (Enterprise Multi-School, National ID, AI Pedagogical Quality & Fair SLA)
-- Single Source of Truth for Architecture & Codebase Development
-- ==============================================================================

SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;

-- ------------------------------------------------------------------------------
-- DROP ALL TABLES IN REVERSE DEPENDENCY ORDER (PRISTINE ZERO-MOCK RESET)
-- ------------------------------------------------------------------------------
DROP TABLE IF EXISTS `video_quality_assessments`;
DROP TABLE IF EXISTS `course_access_passes`;
DROP TABLE IF EXISTS `teacher_reviews`;
DROP TABLE IF EXISTS `teacher_performance_metrics`;
DROP TABLE IF EXISTS `chat_messages`;
DROP TABLE IF EXISTS `student_mastery_analytics`;
DROP TABLE IF EXISTS `student_question_answers`;
DROP TABLE IF EXISTS `exam_attempts`;
DROP TABLE IF EXISTS `question_options`;
DROP TABLE IF EXISTS `questions`;
DROP TABLE IF EXISTS `exams`;
DROP TABLE IF EXISTS `lesson_progress`;
DROP TABLE IF EXISTS `lessons`;
DROP TABLE IF EXISTS `courses`;
DROP TABLE IF EXISTS `subjects`;
DROP TABLE IF EXISTS `guardian_students`;
DROP TABLE IF EXISTS `guardians`;
DROP TABLE IF EXISTS `teachers`;
DROP TABLE IF EXISTS `teacher_profiles`;
DROP TABLE IF EXISTS `students`;
DROP TABLE IF EXISTS `school_rosters`;
DROP TABLE IF EXISTS `schools`;
DROP TABLE IF EXISTS `user_devices`;
DROP TABLE IF EXISTS `otp_verifications`;
DROP TABLE IF EXISTS `auth_identities`;
DROP TABLE IF EXISTS `users`;

-- ------------------------------------------------------------------------------
-- 1. Table: auth_identities (الهوية المركزية للمصادقة عبر رقم الهاتف وأمان الجلسة)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `auth_identities` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  `uuid` CHAR(36) NOT NULL UNIQUE,
  `phone_number` TEXT NOT NULL,
  `phone_hash` VARCHAR(64) NOT NULL UNIQUE,
  `status` ENUM('active', 'pending_otp', 'suspended') NOT NULL DEFAULT 'active',
  `token_version` INT UNSIGNED NOT NULL DEFAULT 1,
  `created_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  `updated_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  KEY `idx_identities_phone_hash` (`phone_hash`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ------------------------------------------------------------------------------
-- 2. Table: schools (المدارس الخاصة، مدارس الثقافة العسكرية، والمراكز الشريكة)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `schools` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  `uuid` CHAR(36) NOT NULL UNIQUE,
  `code` VARCHAR(50) NOT NULL UNIQUE,
  `name` VARCHAR(255) NOT NULL,
  `type` ENUM('military_culture', 'private', 'public', 'center') NOT NULL DEFAULT 'private',
  `director_name` VARCHAR(255) DEFAULT NULL,
  `phone` VARCHAR(50) DEFAULT NULL,
  `city` VARCHAR(100) DEFAULT 'Amman',
  `is_active` TINYINT(1) NOT NULL DEFAULT 1,
  `subscription_status` ENUM('active', 'trial', 'expired') NOT NULL DEFAULT 'active',
  `contract_expires_at` TIMESTAMP NULL DEFAULT NULL,
  `created_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  `updated_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ------------------------------------------------------------------------------
-- 3. Table: school_rosters (كشوفات المدارس المعتمدة بالرقم الوطني والربط التلقائي)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `school_rosters` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  `school_id` BIGINT UNSIGNED NOT NULL,
  `national_id` VARCHAR(20) NOT NULL,
  `student_full_name` VARCHAR(255) NOT NULL,
  `grade_level` VARCHAR(50) NOT NULL DEFAULT 'tawjihi_2008',
  `stream` ENUM('scientific', 'literary', 'vocational', 'general') NOT NULL DEFAULT 'scientific',
  `is_claimed` TINYINT(1) NOT NULL DEFAULT 0,
  `claimed_student_id` BIGINT UNSIGNED DEFAULT NULL,
  `created_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  UNIQUE KEY `idx_school_national_id` (`school_id`, `national_id`),
  KEY `idx_roster_national_id` (`national_id`),
  CONSTRAINT `fk_roster_school` FOREIGN KEY (`school_id`) REFERENCES `schools` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ------------------------------------------------------------------------------
-- 4. Table: students (جدول الطلاب المستقل بالرقم الوطني والمدرسة)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `students` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  `uuid` CHAR(36) NOT NULL UNIQUE,
  `identity_id` BIGINT UNSIGNED DEFAULT NULL,
  `school_id` BIGINT UNSIGNED DEFAULT NULL,
  `national_id` VARCHAR(20) NOT NULL UNIQUE,
  `full_name` VARCHAR(255) NOT NULL,
  `pin_code_hash` VARCHAR(255) DEFAULT NULL,
  `grade_level` VARCHAR(50) NOT NULL DEFAULT 'tawjihi_2008',
  `stream` ENUM('scientific', 'literary', 'vocational', 'general') NOT NULL DEFAULT 'scientific',
  `is_school_sponsored` TINYINT(1) NOT NULL DEFAULT 0,
  `readiness_score` DECIMAL(5, 2) NOT NULL DEFAULT 85.00,
  `created_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  `updated_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  KEY `idx_students_identity` (`identity_id`),
  KEY `idx_students_school` (`school_id`),
  KEY `idx_students_national_id` (`national_id`),
  CONSTRAINT `fk_student_identity` FOREIGN KEY (`identity_id`) REFERENCES `auth_identities` (`id`) ON DELETE SET NULL,
  CONSTRAINT `fk_student_school` FOREIGN KEY (`school_id`) REFERENCES `schools` (`id`) ON DELETE SET NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ------------------------------------------------------------------------------
-- 5. Table: guardians (جدول أولياء الأمور المستقل)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `guardians` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  `uuid` CHAR(36) NOT NULL UNIQUE,
  `identity_id` BIGINT UNSIGNED NOT NULL UNIQUE,
  `national_id` VARCHAR(20) DEFAULT NULL,
  `full_name` VARCHAR(255) NOT NULL,
  `created_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  `updated_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  CONSTRAINT `fk_guardian_identity` FOREIGN KEY (`identity_id`) REFERENCES `auth_identities` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ------------------------------------------------------------------------------
-- 6. Table: guardian_students (ربط ولي الأمر بالأبناء المتعددين 1:N)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `guardian_students` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  `guardian_id` BIGINT UNSIGNED NOT NULL,
  `student_id` BIGINT UNSIGNED NOT NULL,
  `relationship_type` ENUM('father', 'mother', 'brother', 'guardian') NOT NULL DEFAULT 'father',
  `can_view_analytics` TINYINT(1) NOT NULL DEFAULT 1,
  `created_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  UNIQUE KEY `idx_guardian_student_pair` (`guardian_id`, `student_id`),
  CONSTRAINT `fk_gsp_guardian` FOREIGN KEY (`guardian_id`) REFERENCES `guardians` (`id`) ON DELETE CASCADE,
  CONSTRAINT `fk_gsp_student` FOREIGN KEY (`student_id`) REFERENCES `students` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ------------------------------------------------------------------------------
-- 7. Table: teachers (جدول المعلمين المستقل وتحديد المدرسة والاختصاص)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `teachers` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  `uuid` CHAR(36) NOT NULL UNIQUE,
  `identity_id` BIGINT UNSIGNED NOT NULL UNIQUE,
  `school_id` BIGINT UNSIGNED DEFAULT NULL,
  `national_id` VARCHAR(20) DEFAULT NULL,
  `full_name` VARCHAR(255) NOT NULL,
  `specialization` VARCHAR(150) NOT NULL DEFAULT 'الرياضيات العلمي',
  `bio` TEXT DEFAULT NULL,
  `is_school_exclusive` TINYINT(1) NOT NULL DEFAULT 0,
  `is_marketplace_public` TINYINT(1) NOT NULL DEFAULT 1,
  `created_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  `updated_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  KEY `idx_teachers_school` (`school_id`),
  CONSTRAINT `fk_teacher_identity` FOREIGN KEY (`identity_id`) REFERENCES `auth_identities` (`id`) ON DELETE CASCADE,
  CONSTRAINT `fk_teacher_school` FOREIGN KEY (`school_id`) REFERENCES `schools` (`id`) ON DELETE SET NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ------------------------------------------------------------------------------
-- 8. Table: subjects (المباحث الدراسية المعتمدة - التوجيهي والثقافة العسكرية)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `subjects` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  `name` VARCHAR(150) NOT NULL,
  `code` VARCHAR(50) NOT NULL UNIQUE,
  `stream` ENUM('scientific', 'literary', 'vocational', 'common') NOT NULL DEFAULT 'scientific',
  `is_active` TINYINT(1) NOT NULL DEFAULT 1,
  `created_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ------------------------------------------------------------------------------
-- 9. Table: courses (الدورات التدريبية المربوطة بالمعلم والمادة والمدرسة)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `courses` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  `uuid` CHAR(36) NOT NULL UNIQUE,
  `subject_id` BIGINT UNSIGNED NOT NULL,
  `teacher_id` BIGINT UNSIGNED NOT NULL,
  `school_id` BIGINT UNSIGNED DEFAULT NULL,
  `title` VARCHAR(255) NOT NULL,
  `description` TEXT DEFAULT NULL,
  `semester` ENUM('first', 'second', 'full_year', 'intensive') NOT NULL DEFAULT 'first',
  `price_jod` DECIMAL(8, 2) NOT NULL DEFAULT 35.00,
  `thumbnail_url` VARCHAR(500) DEFAULT NULL,
  `is_school_exclusive` TINYINT(1) NOT NULL DEFAULT 0,
  `is_system_curriculum` TINYINT(1) NOT NULL DEFAULT 0 COMMENT 'الدورة الرئيسية للمنهاج الوزاري — تُستخدم لرفع فيديوهات الذكاء الاصطناعي',
  `grade_level` VARCHAR(50) DEFAULT NULL COMMENT 'المرحلة الدراسية مثل: tawjihi_2008',
  `stream` ENUM('scientific','literary','vocational','general') DEFAULT NULL COMMENT 'الفرع الدراسي',
  `is_published` TINYINT(1) NOT NULL DEFAULT 1,
  `created_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  `updated_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  KEY `idx_courses_subject` (`subject_id`),
  KEY `idx_courses_teacher` (`teacher_id`),
  KEY `idx_courses_school` (`school_id`),
  KEY `idx_courses_grade_stream` (`grade_level`, `stream`),
  KEY `idx_courses_system` (`is_system_curriculum`),
  CONSTRAINT `fk_courses_subject` FOREIGN KEY (`subject_id`) REFERENCES `subjects` (`id`) ON DELETE RESTRICT,
  CONSTRAINT `fk_courses_teacher` FOREIGN KEY (`teacher_id`) REFERENCES `teachers` (`id`) ON DELETE CASCADE,
  CONSTRAINT `fk_courses_school` FOREIGN KEY (`school_id`) REFERENCES `schools` (`id`) ON DELETE SET NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ------------------------------------------------------------------------------
-- 10. Table: lessons (الدروس وبث HLS المقسم عبر Cloudflare R2 والفهرس الزمني)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `lessons` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  `course_id` BIGINT UNSIGNED NOT NULL,
  `title` VARCHAR(255) NOT NULL,
  `sequence_order` INT UNSIGNED NOT NULL DEFAULT 1,
  
  -- المعلم الحقيقي (Teacher Video)
  `video_uuid` VARCHAR(64) DEFAULT NULL,
  `hls_url` VARCHAR(500) DEFAULT NULL,
  `timeline_chapters_json` JSON DEFAULT NULL,
  `bunny_video_id` VARCHAR(100) DEFAULT NULL,
  `duration_seconds` INT UNSIGNED NOT NULL DEFAULT 0,
  
  -- الذكاء الاصطناعي (NotebookLM / AI Audio-Video Explanations)
  `ai_podcast_url` VARCHAR(500) DEFAULT NULL COMMENT 'رابط الشرح الصوتي المولد بالذكاء الاصطناعي (NotebookLM style)',
  `ai_video_url` VARCHAR(500) DEFAULT NULL COMMENT 'رابط فيديو الشرح الآلي بالذكاء الاصطناعي',
  
  -- المحتوى النصي المفرغ من الـ PDF والتوليد الذكي
  `markdown_content` LONGTEXT DEFAULT NULL COMMENT 'محتوى الدرس النصي بصيغة Markdown و LaTeX',
  `cheat_sheet_markdown` LONGTEXT DEFAULT NULL COMMENT 'ملخص الدرس السريع (Cheat Sheet)',
  `socratic_quiz_json` JSON DEFAULT NULL COMMENT 'الفحص السقراطي الذكي (سؤال وجواب)',
  
  `is_free_preview` TINYINT(1) NOT NULL DEFAULT 0,
  `created_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  `updated_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  KEY `idx_lessons_course` (`course_id`),
  KEY `idx_lessons_video_uuid` (`video_uuid`),
  CONSTRAINT `fk_lessons_course` FOREIGN KEY (`course_id`) REFERENCES `courses` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ------------------------------------------------------------------------------
-- 10.5. Table: lesson_resources (المصادر المرفقة للدرس: كتب، ملخصات، أوراق عمل PDF)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `lesson_resources` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  `lesson_id` BIGINT UNSIGNED NOT NULL,
  `title` VARCHAR(255) NOT NULL,
  `resource_type` ENUM('book_pdf', 'summary_pdf', 'worksheet_pdf', 'external_link') NOT NULL DEFAULT 'summary_pdf',
  `file_url` VARCHAR(500) NOT NULL,
  `is_ai_generated` TINYINT(1) NOT NULL DEFAULT 0,
  `created_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  KEY `idx_resources_lesson` (`lesson_id`),
  CONSTRAINT `fk_resources_lesson` FOREIGN KEY (`lesson_id`) REFERENCES `lessons` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ------------------------------------------------------------------------------
-- 11. Table: video_quality_assessments (تقييم جودة المحتوى التعليمي والتوافق بالذكاء الاصطناعي)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `video_quality_assessments` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  `lesson_id` BIGINT UNSIGNED NOT NULL UNIQUE,
  `curriculum_alignment_score` DECIMAL(5, 2) NOT NULL DEFAULT 95.00,
  `pedagogical_clarity_score` DECIMAL(5, 2) NOT NULL DEFAULT 92.00,
  `learning_outcomes_json` JSON DEFAULT NULL,
  `bloom_coverage_json` JSON DEFAULT NULL,
  `ai_critique_text` TEXT DEFAULT NULL,
  `approval_status` ENUM('approved_official', 'needs_revision', 'pending_ai') NOT NULL DEFAULT 'approved_official',
  `evaluated_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  CONSTRAINT `fk_vqa_lesson` FOREIGN KEY (`lesson_id`) REFERENCES `lessons` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ------------------------------------------------------------------------------
-- 12. Table: exams (الامتحانات: فحص سقراطي، امتحان درس، وحدة، وامتحان وزاري)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `exams` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  `uuid` CHAR(36) NOT NULL UNIQUE,
  `course_id` BIGINT UNSIGNED NOT NULL,
  `lesson_id` BIGINT UNSIGNED DEFAULT NULL,
  `created_by_id` BIGINT UNSIGNED DEFAULT NULL,
  `creator_type` ENUM('teacher', 'ai_adaptive', 'ministry_standard') NOT NULL DEFAULT 'ai_adaptive',
  `scope` ENUM('in_video_checkpoint', 'lesson_exam', 'unit_exam', 'semester_final') NOT NULL DEFAULT 'in_video_checkpoint',
  `title` VARCHAR(255) NOT NULL,
  `description` TEXT DEFAULT NULL,
  `duration_minutes` INT UNSIGNED NOT NULL DEFAULT 30,
  `timestamp_seconds` INT UNSIGNED NOT NULL DEFAULT 0,
  `rewind_on_fail_seconds` INT UNSIGNED NOT NULL DEFAULT 45,
  `passing_percentage` DECIMAL(5, 2) NOT NULL DEFAULT 60.00,
  `total_points` INT UNSIGNED NOT NULL DEFAULT 100,
  `is_mandatory` TINYINT(1) NOT NULL DEFAULT 1,
  `is_published` TINYINT(1) NOT NULL DEFAULT 1,
  `created_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  `updated_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  KEY `idx_exams_course` (`course_id`),
  KEY `idx_exams_lesson` (`lesson_id`),
  CONSTRAINT `fk_exams_course` FOREIGN KEY (`course_id`) REFERENCES `courses` (`id`) ON DELETE CASCADE,
  CONSTRAINT `fk_exams_lesson` FOREIGN KEY (`lesson_id`) REFERENCES `lessons` (`id`) ON DELETE SET NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ------------------------------------------------------------------------------
-- 13. Table: questions (الأسئلة والتحليل المعرفي وهرمية بلوم)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `questions` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  `uuid` CHAR(36) NOT NULL UNIQUE,
  `exam_id` BIGINT UNSIGNED NOT NULL,
  `question_text` TEXT NOT NULL,
  `question_type` ENUM('multiple_choice', 'true_false', 'short_answer') NOT NULL DEFAULT 'multiple_choice',
  `bloom_taxonomy` ENUM('recall', 'comprehension', 'application', 'analysis') NOT NULL DEFAULT 'comprehension',
  `topic_tag` VARCHAR(150) DEFAULT NULL,
  `points` INT UNSIGNED NOT NULL DEFAULT 10,
  `explanation_text` TEXT DEFAULT NULL,
  `ai_hint` TEXT DEFAULT NULL,
  `created_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  KEY `idx_questions_exam` (`exam_id`),
  CONSTRAINT `fk_questions_exam` FOREIGN KEY (`exam_id`) REFERENCES `exams` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ------------------------------------------------------------------------------
-- 14. Table: question_options (خيارات الإجابة والتغذية الراجعة الفورية)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `question_options` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  `question_id` BIGINT UNSIGNED NOT NULL,
  `option_text` TEXT NOT NULL,
  `is_correct` TINYINT(1) NOT NULL DEFAULT 0,
  `feedback_text` TEXT DEFAULT NULL,
  PRIMARY KEY (`id`),
  KEY `idx_options_question` (`question_id`),
  CONSTRAINT `fk_options_question` FOREIGN KEY (`question_id`) REFERENCES `questions` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ------------------------------------------------------------------------------
-- 15. Table: exam_attempts (محاولات ونتائج الامتحانات وتحليل الفجوات)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `exam_attempts` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  `uuid` CHAR(36) NOT NULL UNIQUE,
  `student_id` BIGINT UNSIGNED NOT NULL,
  `exam_id` BIGINT UNSIGNED NOT NULL,
  `attempt_number` INT UNSIGNED NOT NULL DEFAULT 1,
  `score` DECIMAL(6, 2) NOT NULL DEFAULT 0.00,
  `total_score` DECIMAL(6, 2) NOT NULL DEFAULT 100.00,
  `percentage` DECIMAL(5, 2) NOT NULL DEFAULT 0.00,
  `status` ENUM('passed', 'failed', 'needs_remediation', 'in_progress') NOT NULL DEFAULT 'in_progress',
  `time_spent_seconds` INT UNSIGNED NOT NULL DEFAULT 0,
  `weak_topics_json` JSON DEFAULT NULL,
  `ai_diagnostic_report` TEXT DEFAULT NULL,
  `created_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  KEY `idx_attempts_student` (`student_id`),
  KEY `idx_attempts_exam` (`exam_id`),
  CONSTRAINT `fk_attempts_student` FOREIGN KEY (`student_id`) REFERENCES `students` (`id`) ON DELETE CASCADE,
  CONSTRAINT `fk_attempts_exam` FOREIGN KEY (`exam_id`) REFERENCES `exams` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ------------------------------------------------------------------------------
-- 16. Table: teacher_reviews (تقييمات الطلاب المحصنة بالأوزان وخاصية كشف الكيد)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `teacher_reviews` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  `teacher_id` BIGINT UNSIGNED NOT NULL,
  `student_id` BIGINT UNSIGNED NOT NULL,
  `course_id` BIGINT UNSIGNED DEFAULT NULL,
  `lesson_id` BIGINT UNSIGNED DEFAULT NULL,
  `rating_overall` DECIMAL(3, 2) NOT NULL DEFAULT 5.00,
  `rating_clarity` INT NOT NULL DEFAULT 5,
  `rating_response_speed` INT NOT NULL DEFAULT 5,
  `rating_socratic_interaction` INT NOT NULL DEFAULT 5,
  `review_text` TEXT DEFAULT NULL,
  `review_weight` DECIMAL(4, 3) NOT NULL DEFAULT 1.000,
  `student_watch_percentage` DECIMAL(5, 2) NOT NULL DEFAULT 100.00,
  `socratic_accuracy_rate` DECIMAL(5, 2) NOT NULL DEFAULT 100.00,
  `is_flagged_anomaly` TINYINT(1) NOT NULL DEFAULT 0,
  `is_verified` TINYINT(1) NOT NULL DEFAULT 1,
  `created_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  KEY `idx_tr_teacher` (`teacher_id`),
  KEY `idx_tr_student` (`student_id`),
  CONSTRAINT `fk_tr_teacher` FOREIGN KEY (`teacher_id`) REFERENCES `teachers` (`id`) ON DELETE CASCADE,
  CONSTRAINT `fk_tr_student` FOREIGN KEY (`student_id`) REFERENCES `students` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ------------------------------------------------------------------------------
-- 17. Table: teacher_performance_metrics (مؤشرات الجدارة التراكمية وطابور الاستجابة العادل)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `teacher_performance_metrics` (
  `teacher_id` BIGINT UNSIGNED NOT NULL,
  `avg_response_minutes` INT NOT NULL DEFAULT 4,
  `response_rate_percentage` DECIMAL(5, 2) NOT NULL DEFAULT 98.50,
  `active_queue_count` INT UNSIGNED NOT NULL DEFAULT 0,
  `total_students_enrolled` INT UNSIGNED NOT NULL DEFAULT 0,
  `total_reviews_count` INT UNSIGNED NOT NULL DEFAULT 0,
  `raw_avg_rating` DECIMAL(3, 2) NOT NULL DEFAULT 5.00,
  `weighted_student_rating` DECIMAL(3, 2) NOT NULL DEFAULT 5.00,
  `ai_engagement_score` DECIMAL(5, 2) NOT NULL DEFAULT 96.00,
  `sla_speed_score` DECIMAL(5, 2) NOT NULL DEFAULT 98.00,
  `mastery_impact_score` DECIMAL(5, 2) NOT NULL DEFAULT 94.00,
  `composite_merit_score` DECIMAL(5, 2) NOT NULL DEFAULT 96.50,
  `star_equivalent` DECIMAL(3, 2) NOT NULL DEFAULT 4.90,
  `reputation_tier` VARCHAR(100) NOT NULL DEFAULT 'معلم نخبوي معتمد 💎',
  `last_calculated_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`teacher_id`),
  CONSTRAINT `fk_tpm_teacher` FOREIGN KEY (`teacher_id`) REFERENCES `teachers` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ------------------------------------------------------------------------------
-- 18. Table: course_access_passes (تصاريح واشتراكات الطلاب: مدرسي مجاني أو ميكرو مخفض)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `course_access_passes` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  `student_id` BIGINT UNSIGNED NOT NULL,
  `course_id` BIGINT UNSIGNED NOT NULL,
  `teacher_id` BIGINT UNSIGNED NOT NULL,
  `pass_type` ENUM('school_included', 'discounted_micro_pass', 'full_marketplace') NOT NULL DEFAULT 'school_included',
  `price_paid_jod` DECIMAL(6, 2) NOT NULL DEFAULT 0.00,
  `expires_at` TIMESTAMP NULL DEFAULT NULL,
  `is_active` TINYINT(1) NOT NULL DEFAULT 1,
  `created_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  KEY `idx_cap_student` (`student_id`),
  KEY `idx_cap_course` (`course_id`),
  CONSTRAINT `fk_cap_student` FOREIGN KEY (`student_id`) REFERENCES `students` (`id`) ON DELETE CASCADE,
  CONSTRAINT `fk_cap_course` FOREIGN KEY (`course_id`) REFERENCES `courses` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ------------------------------------------------------------------------------
-- 19. Table: chat_messages (المحادثات المباشرة بين الطلاب والمعلمين عبر Workerman)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `chat_messages` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  `uuid` CHAR(36) NOT NULL UNIQUE,
  `sender_identity_id` BIGINT UNSIGNED NOT NULL,
  `receiver_identity_id` BIGINT UNSIGNED NOT NULL,
  `course_id` BIGINT UNSIGNED DEFAULT NULL,
  `lesson_id` BIGINT UNSIGNED DEFAULT NULL,
  `message` TEXT NOT NULL,
  `message_type` ENUM('text', 'voice', 'image', 'file') NOT NULL DEFAULT 'text',
  `media_url` VARCHAR(500) DEFAULT NULL,
  `is_read` TINYINT(1) NOT NULL DEFAULT 0,
  `read_at` TIMESTAMP NULL DEFAULT NULL,
  `created_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  KEY `idx_chat_identities` (`sender_identity_id`, `receiver_identity_id`),
  KEY `idx_chat_unread` (`receiver_identity_id`, `is_read`),
  CONSTRAINT `fk_chat_sender_id` FOREIGN KEY (`sender_identity_id`) REFERENCES `auth_identities` (`id`) ON DELETE CASCADE,
  CONSTRAINT `fk_chat_receiver_id` FOREIGN KEY (`receiver_identity_id`) REFERENCES `auth_identities` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

-- ------------------------------------------------------------------------------
-- 20. Table: otp_verifications (رموز التحقق عبر الواتساب وبوابة نبيه)
-- ------------------------------------------------------------------------------
CREATE TABLE IF NOT EXISTS `otp_verifications` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  `phone_hash` VARCHAR(64) NOT NULL,
  `otp_code_hash` VARCHAR(255) NOT NULL,
  `attempts` INT UNSIGNED NOT NULL DEFAULT 0,
  `is_used` TINYINT(1) NOT NULL DEFAULT 0,
  `expires_at` TIMESTAMP NOT NULL,
  `created_at` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  KEY `idx_otp_phone_hash` (`phone_hash`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

SET FOREIGN_KEY_CHECKS = 1;