-- CreateTable
CREATE TABLE `users` (
    `id` INTEGER NOT NULL AUTO_INCREMENT,
    `email` VARCHAR(191) NOT NULL,
    `password` VARCHAR(191) NOT NULL,
    `nickname` VARCHAR(191) NOT NULL,
    `persona` ENUM('senior', 'mid', 'junior', 'crammer') NOT NULL DEFAULT 'mid',
    `currentGrade` INTEGER NULL,
    `targetGrade` INTEGER NULL,
    `reviewIntensity` ENUM('strict', 'moderate', 'relaxed') NOT NULL DEFAULT 'moderate',
    `onboardedAt` DATETIME(3) NULL,
    `createdAt` DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),
    `updatedAt` DATETIME(3) NOT NULL,

    UNIQUE INDEX `users_email_key`(`email`),
    PRIMARY KEY (`id`)
) DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

-- CreateTable
CREATE TABLE `subjects` (
    `id` INTEGER NOT NULL AUTO_INCREMENT,
    `name` VARCHAR(191) NOT NULL,
    `color` VARCHAR(191) NOT NULL DEFAULT '#6366f1',
    `userId` INTEGER NOT NULL,
    `createdAt` DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),

    INDEX `subjects_userId_idx`(`userId`),
    UNIQUE INDEX `subjects_userId_name_key`(`userId`, `name`),
    PRIMARY KEY (`id`)
) DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

-- CreateTable
CREATE TABLE `tags` (
    `id` INTEGER NOT NULL AUTO_INCREMENT,
    `name` VARCHAR(191) NOT NULL,
    `subjectId` INTEGER NOT NULL,
    `createdAt` DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),

    INDEX `tags_subjectId_idx`(`subjectId`),
    UNIQUE INDEX `tags_subjectId_name_key`(`subjectId`, `name`),
    PRIMARY KEY (`id`)
) DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

-- CreateTable
CREATE TABLE `study_logs` (
    `id` INTEGER NOT NULL AUTO_INCREMENT,
    `userId` INTEGER NOT NULL,
    `subjectId` INTEGER NOT NULL,
    `tagId` INTEGER NULL,
    `title` VARCHAR(191) NOT NULL,
    `difficulty` DOUBLE NOT NULL,
    `baseCorrectRate` DOUBLE NULL,
    `result` ENUM('correct', 'incorrect', 'partial') NOT NULL,
    `memo` TEXT NULL,
    `studiedAt` DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),
    `timeSpent` INTEGER NULL,

    INDEX `study_logs_userId_studiedAt_idx`(`userId`, `studiedAt`),
    INDEX `study_logs_subjectId_idx`(`subjectId`),
    INDEX `study_logs_tagId_idx`(`tagId`),
    PRIMARY KEY (`id`)
) DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

-- CreateTable
CREATE TABLE `review_schedules` (
    `id` INTEGER NOT NULL AUTO_INCREMENT,
    `userId` INTEGER NOT NULL,
    `studyLogId` INTEGER NOT NULL,
    `scheduledAt` DATETIME(3) NOT NULL,
    `reviewedAt` DATETIME(3) NULL,
    `result` ENUM('correct', 'incorrect', 'partial') NULL,
    `iteration` INTEGER NOT NULL DEFAULT 0,
    `predictedP` DOUBLE NULL,
    `status` ENUM('pending', 'done', 'skipped', 'expired') NOT NULL DEFAULT 'pending',
    `createdAt` DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),
    `updatedAt` DATETIME(3) NOT NULL,

    INDEX `review_schedules_userId_status_scheduledAt_idx`(`userId`, `status`, `scheduledAt`),
    INDEX `review_schedules_studyLogId_idx`(`studyLogId`),
    PRIMARY KEY (`id`)
) DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

-- CreateTable
CREATE TABLE `skill_snapshots` (
    `id` INTEGER NOT NULL AUTO_INCREMENT,
    `userId` INTEGER NOT NULL,
    `tagId` INTEGER NULL,
    `s0` DOUBLE NOT NULL,
    `lastUpdatedAt` DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),
    `sampleCount` INTEGER NOT NULL DEFAULT 0,

    INDEX `skill_snapshots_userId_idx`(`userId`),
    UNIQUE INDEX `skill_snapshots_userId_tagId_key`(`userId`, `tagId`),
    PRIMARY KEY (`id`)
) DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

-- AddForeignKey
ALTER TABLE `subjects` ADD CONSTRAINT `subjects_userId_fkey` FOREIGN KEY (`userId`) REFERENCES `users`(`id`) ON DELETE CASCADE ON UPDATE CASCADE;

-- AddForeignKey
ALTER TABLE `tags` ADD CONSTRAINT `tags_subjectId_fkey` FOREIGN KEY (`subjectId`) REFERENCES `subjects`(`id`) ON DELETE CASCADE ON UPDATE CASCADE;

-- AddForeignKey
ALTER TABLE `study_logs` ADD CONSTRAINT `study_logs_userId_fkey` FOREIGN KEY (`userId`) REFERENCES `users`(`id`) ON DELETE CASCADE ON UPDATE CASCADE;

-- AddForeignKey
ALTER TABLE `study_logs` ADD CONSTRAINT `study_logs_subjectId_fkey` FOREIGN KEY (`subjectId`) REFERENCES `subjects`(`id`) ON DELETE RESTRICT ON UPDATE CASCADE;

-- AddForeignKey
ALTER TABLE `study_logs` ADD CONSTRAINT `study_logs_tagId_fkey` FOREIGN KEY (`tagId`) REFERENCES `tags`(`id`) ON DELETE SET NULL ON UPDATE CASCADE;

-- AddForeignKey
ALTER TABLE `review_schedules` ADD CONSTRAINT `review_schedules_userId_fkey` FOREIGN KEY (`userId`) REFERENCES `users`(`id`) ON DELETE CASCADE ON UPDATE CASCADE;

-- AddForeignKey
ALTER TABLE `review_schedules` ADD CONSTRAINT `review_schedules_studyLogId_fkey` FOREIGN KEY (`studyLogId`) REFERENCES `study_logs`(`id`) ON DELETE CASCADE ON UPDATE CASCADE;

-- AddForeignKey
ALTER TABLE `skill_snapshots` ADD CONSTRAINT `skill_snapshots_userId_fkey` FOREIGN KEY (`userId`) REFERENCES `users`(`id`) ON DELETE CASCADE ON UPDATE CASCADE;

-- AddForeignKey
ALTER TABLE `skill_snapshots` ADD CONSTRAINT `skill_snapshots_tagId_fkey` FOREIGN KEY (`tagId`) REFERENCES `tags`(`id`) ON DELETE SET NULL ON UPDATE CASCADE;