package repository

import (
	"context"
	"errors"
	"time"

	"fashionapi/internal/dto"
	"fashionapi/internal/model"

	"gorm.io/gorm"
)

// ReviewRepository 审核草稿的数据访问接口。
//
// 草稿由爬虫 worker 写入（见 IngestRepository），本接口负责「读 + 晋升」：
// 列出待审草稿、查看详情、审核前微调字段、通过时晋升到正式表、驳回时标记状态。
type ReviewRepository interface {
	// ListDrafts 分页列出草稿；status 为空表示全部，否则按状态过滤。
	// 排序：pending 优先，其次按 id 倒序（最新在前）。
	ListDrafts(ctx context.Context, status string, page, size int) ([]model.BrandRunwayDraft, int64, error)
	// DraftDetail 查单条草稿（不含图片）。
	DraftDetail(ctx context.Context, id uint32) (*model.BrandRunwayDraft, error)
	// DraftImages 查草稿的全部图片，按排序值升序。
	DraftImages(ctx context.Context, draftID uint32) ([]model.BrandRunwayDraftImage, error)
	// UpdateDraft 审核前微调草稿字段（白名单，杜绝任意列注入）。
	UpdateDraft(ctx context.Context, id uint32, fields map[string]any) error
	// SetDraftStatus 设置草稿状态（通过/驳回）与审核人/驳回理由。
	SetDraftStatus(ctx context.Context, id uint32, status, reviewer, reason string) error
	// SaveRunwayFromDraft 晋升：按实体键（brand_id + season_code + collection_type）幂等 upsert 到 brand_runway 正式表并替换图片，返回正式表主键。
	SaveRunwayFromDraft(ctx context.Context, draftID uint32) (uint32, error)
	// 街拍草稿镜像方法（与 runway 同构，但对象为 street_snap_draft / street_snap）。
	ListStreetDrafts(ctx context.Context, status string, page, size int) ([]model.StreetSnapDraft, int64, error)
	StreetDraftDetail(ctx context.Context, id uint32) (*model.StreetSnapDraft, error)
	StreetDraftImages(ctx context.Context, draftID uint32) ([]model.StreetSnapDraftImage, error)
	// SoftDeleteRunwayDraftImage 软删单张走秀草稿图片（审核阶段剔除坏图），并同步 image_count。
	SoftDeleteRunwayDraftImage(ctx context.Context, draftID, imgID uint32) error
	// SoftDeleteStreetDraftImage 软删单张街拍草稿图片，并同步 image_count。
	SoftDeleteStreetDraftImage(ctx context.Context, draftID, imgID uint32) error
	// GetDraftImageKey 取单张草稿图片的七牛 key（删除前清理用）；不存在返回空串。
	GetDraftImageKey(ctx context.Context, kind string, draftID, imgID uint32) (string, error)
	UpdateStreetDraft(ctx context.Context, id uint32, fields map[string]any) error
	SetStreetDraftStatus(ctx context.Context, id uint32, status, reviewer, reason string) error
	SaveStreetSnapFromDraft(ctx context.Context, draftID uint32) (uint32, error)
	// CountDraftPending 统计某草稿表（dest 传表对应的零值指针，如 &model.BrandRunwayDraft{}）中指定状态的草稿数。
	// 供各 ReviewModule 复用，新增模块无需再单独写计数方法。
	CountDraftPending(ctx context.Context, status string, dest any) (int64, error)
}

type reviewRepository struct {
	db *gorm.DB
}

// NewReviewRepository 创建审核仓储。
func NewReviewRepository(db *gorm.DB) ReviewRepository {
	return &reviewRepository{db: db}
}

func (r *reviewRepository) ListDrafts(ctx context.Context, status string, page, size int) ([]model.BrandRunwayDraft, int64, error) {
	if page < 1 {
		page = 1
	}
	if size < 1 || size > 100 {
		size = 20
	}
	q := r.db.WithContext(ctx).Model(&model.BrandRunwayDraft{}).Where("is_deleted = 0")
	if status != "" {
		q = q.Where("status = ?", status)
	}
	var total int64
	if err := q.Count(&total).Error; err != nil {
		return nil, 0, err
	}
	if total == 0 {
		return []model.BrandRunwayDraft{}, 0, nil
	}
	var rows []model.BrandRunwayDraft
	if err := q.
		Order("CASE status WHEN '" + model.DraftStatusPending + "' THEN 0 ELSE 1 END ASC, id DESC").
		Offset((page - 1) * size).
		Limit(size).
		Find(&rows).Error; err != nil {
		return nil, 0, err
	}
	return rows, total, nil
}

func (r *reviewRepository) DraftDetail(ctx context.Context, id uint32) (*model.BrandRunwayDraft, error) {
	var d model.BrandRunwayDraft
	if err := r.db.WithContext(ctx).Where("id = ? AND is_deleted = 0", id).First(&d).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, ErrNotFound
		}
		return nil, err
	}
	return &d, nil
}

func (r *reviewRepository) DraftImages(ctx context.Context, draftID uint32) ([]model.BrandRunwayDraftImage, error) {
	var imgs []model.BrandRunwayDraftImage
	err := r.db.WithContext(ctx).
		Where("draft_id = ? AND is_deleted = 0", draftID).
		Order("sort_order ASC, id ASC").
		Find(&imgs).Error
	return imgs, err
}

// draftEditable 审核前可微调的字段白名单（键即列名）。
var draftEditable = map[string]bool{
	"title_en":        true,
	"title_cn":        true,
	"description_en":  true,
	"description_cn":  true,
	"year":            true,
	"season":          true,
	"collection_type": true,
	"season_code":     true,
}

// UpdateDraft 只更新白名单内的字段，其余忽略，杜绝任意列注入。
func (r *reviewRepository) UpdateDraft(ctx context.Context, id uint32, fields map[string]any) error {
	clean := map[string]any{}
	for k, v := range fields {
		if draftEditable[k] {
			clean[k] = v
		}
	}
	if len(clean) == 0 {
		return nil
	}
	clean["updated_at"] = uint32(time.Now().Unix())
	return r.db.WithContext(ctx).
		Model(&model.BrandRunwayDraft{}).
		Where("id = ?", id).
		Updates(clean).Error
}

func (r *reviewRepository) SetDraftStatus(ctx context.Context, id uint32, status, reviewer, reason string) error {
	return r.db.WithContext(ctx).
		Model(&model.BrandRunwayDraft{}).
		Where("id = ?", id).
		Updates(map[string]any{
			"status":        status,
			"reviewer":      reviewer,
			"reject_reason": reason,
			"updated_at":    uint32(time.Now().Unix()),
		}).Error
}

// SaveRunwayFromDraft 晋升草稿到正式表：
//  1. 按实体键（brand_id + season_code + collection_type）查找已存在的正式走秀（幂等：重审同一草稿只更新，不重复建行）；
//  2. 存在则更新全部可编辑字段 + 图片数；不存在则新建；
//  3. 替换图片：软删旧图（is_deleted=1）+ 按草稿图片重建；
//  4. 返回正式表主键。
//
// 在事务内完成，保证草稿与正式表一致性。
func (r *reviewRepository) SaveRunwayFromDraft(ctx context.Context, draftID uint32) (uint32, error) {
	var draft model.BrandRunwayDraft
	if err := r.db.WithContext(ctx).Where("id = ? AND is_deleted = 0", draftID).First(&draft).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return 0, ErrNotFound
		}
		return 0, err
	}
	// 多来源聚合：当前草稿图 + 同实体已 approved 的其他草稿图（按 image URL 去重，
	// 七牛 key 已是 sha1，同图 URL 必相同）。当前正被审核的草稿强制纳入，其余只取已审核来源。
	curImgs, err := r.DraftImages(ctx, draftID)
	if err != nil {
		return 0, err
	}
	sibImgs, err := r.runwayApprovedSiblingImages(ctx, draftID, draft.BrandID, draft.SeasonCode, draft.CollectionType)
	if err != nil {
		return 0, err
	}
	imgs := unionRunwayDraftImages(curImgs, sibImgs)

	// image_count 仅计主图（is_detail=0）：对外列表卡片「N 张」与详情默认画廊都只展示主图，
	// 细节图作为主图的附属按需展开，不计入主图数。
	mainCount := 0
	for _, im := range imgs {
		if im.IsDetail == 0 {
			mainCount++
		}
	}

	now := uint32(time.Now().Unix())
	var runwayID uint32
	err = r.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
		// 1) 按实体键查找既有正式走秀
		var existing model.BrandRunway
		if eErr := tx.Where("brand_id = ? AND season_code = ? AND collection_type = ? AND is_deleted = 0", draft.BrandID, draft.SeasonCode, draft.CollectionType).
			Limit(1).Find(&existing).Error; eErr != nil {
			return eErr
		}

		common := map[string]any{
			"title_en":        draft.TitleEn,
			"title_cn":        draft.TitleCn,
			"description_en":  draft.DescriptionEn,
			"description_cn":  draft.DescriptionCn,
			"year":            draft.Year,
			"season":          draft.Season,
			"collection_type": draft.CollectionType,
			"season_code":     draft.SeasonCode,
			"cover":           draft.Cover,
			"image_count":     uint16(mainCount),
			"updated_at":      now,
		}

		if existing.ID != 0 {
			runwayID = existing.ID
			common["brand_id"] = existing.BrandID // 保留正式表的品牌归属
			if uErr := tx.Model(&model.BrandRunway{}).Where("id = ?", runwayID).Updates(common).Error; uErr != nil {
				return uErr
			}
		} else {
			rw := &model.BrandRunway{
				BrandID:        draft.BrandID,
				TitleEn:        draft.TitleEn,
				TitleCn:        draft.TitleCn,
				DescriptionEn:  draft.DescriptionEn,
				DescriptionCn:  draft.DescriptionCn,
				Year:           draft.Year,
				Season:         draft.Season,
				CollectionType: draft.CollectionType,
				SeasonCode:     draft.SeasonCode,
				Cover:          draft.Cover,
				ImageCount:     uint16(mainCount),
				CreatedAt:      now,
				UpdatedAt:      now,
			}
			if cErr := tx.Create(rw).Error; cErr != nil {
				return cErr
			}
			runwayID = rw.ID
		}

		// 2) 替换图片：软删旧 + 重建
		if dErr := tx.Model(&model.BrandRunwayImage{}).
			Where("runway_id = ? AND is_deleted = 0", runwayID).
			Updates(map[string]any{"is_deleted": 1, "updated_at": now}).Error; dErr != nil {
			return dErr
		}
		if len(imgs) > 0 {
			rows := make([]model.BrandRunwayImage, 0, len(imgs))
			for i, im := range imgs {
				rows = append(rows, model.BrandRunwayImage{
					RunwayID:    runwayID,
					BrandID:     draft.BrandID,
					Image:       im.Image,
					Name:        im.Name,
					SortOrder:   uint32(i + 1),
					LookIndex:   im.LookIndex,
					IsDetail:    im.IsDetail,
					Phash:       im.Phash,
					IsDuplicate: im.IsDuplicate,
					DupOf:       im.DupOf,
					CreatedAt:   now,
					UpdatedAt:   now,
				})
			}
			if cErr := tx.Create(&rows).Error; cErr != nil {
				return cErr
			}
		}
		return nil
	})
	if err != nil {
		return 0, err
	}
	return runwayID, nil
}

// CountDraftPending 统计传入表（dest 零值指针）中指定状态的草稿数；供各 ReviewModule 复用。
func (r *reviewRepository) CountDraftPending(ctx context.Context, status string, dest any) (int64, error) {
	var n int64
	if err := r.db.WithContext(ctx).
		Model(dest).
		Where("status = ? AND is_deleted = 0", status).
		Count(&n).Error; err != nil {
		return 0, err
	}
	return n, nil
}

// ---- 街拍草稿镜像实现（与 runway 同构） ----

func (r *reviewRepository) ListStreetDrafts(ctx context.Context, status string, page, size int) ([]model.StreetSnapDraft, int64, error) {
	if page < 1 {
		page = 1
	}
	if size < 1 || size > 100 {
		size = 20
	}
	q := r.db.WithContext(ctx).Model(&model.StreetSnapDraft{}).Where("is_deleted = 0")
	if status != "" {
		q = q.Where("status = ?", status)
	}
	var total int64
	if err := q.Count(&total).Error; err != nil {
		return nil, 0, err
	}
	if total == 0 {
		return []model.StreetSnapDraft{}, 0, nil
	}
	var rows []model.StreetSnapDraft
	if err := q.
		Order("CASE status WHEN '" + model.DraftStatusPending + "' THEN 0 ELSE 1 END ASC, id DESC").
		Offset((page - 1) * size).
		Limit(size).
		Find(&rows).Error; err != nil {
		return nil, 0, err
	}
	return rows, total, nil
}

func (r *reviewRepository) StreetDraftDetail(ctx context.Context, id uint32) (*model.StreetSnapDraft, error) {
	var d model.StreetSnapDraft
	if err := r.db.WithContext(ctx).Where("id = ? AND is_deleted = 0", id).First(&d).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, ErrNotFound
		}
		return nil, err
	}
	return &d, nil
}

func (r *reviewRepository) StreetDraftImages(ctx context.Context, draftID uint32) ([]model.StreetSnapDraftImage, error) {
	var imgs []model.StreetSnapDraftImage
	err := r.db.WithContext(ctx).
		Where("draft_id = ? AND is_deleted = 0", draftID).
		Order("sort_order ASC, id ASC").
		Find(&imgs).Error
	return imgs, err
}

// streetDraftEditable 街拍草稿可微调字段白名单（title / year / city）。
var streetDraftEditable = map[string]bool{
	"title": true,
	"year":  true,
	"city":  true,
}

func (r *reviewRepository) UpdateStreetDraft(ctx context.Context, id uint32, fields map[string]any) error {
	clean := map[string]any{}
	for k, v := range fields {
		if streetDraftEditable[k] {
			clean[k] = v
		}
	}
	if len(clean) == 0 {
		return nil
	}
	clean["updated_at"] = uint32(time.Now().Unix())
	return r.db.WithContext(ctx).
		Model(&model.StreetSnapDraft{}).
		Where("id = ?", id).
		Updates(clean).Error
}

func (r *reviewRepository) SetStreetDraftStatus(ctx context.Context, id uint32, status, reviewer, reason string) error {
	return r.db.WithContext(ctx).
		Model(&model.StreetSnapDraft{}).
		Where("id = ?", id).
		Updates(map[string]any{
			"status":        status,
			"reviewer":      reviewer,
			"reject_reason": reason,
			"updated_at":    uint32(time.Now().Unix()),
		}).Error
}

// SaveStreetSnapFromDraft 晋升街拍草稿到正式表 street_snap（按实体键 city+year 幂等 upsert，替换图片）。
// 逻辑与 SaveRunwayFromDraft 同构，但无 brand_id、有 city，图片明细落到 street_snap_images。
// 在事务内完成，保证草稿与正式表一致性。
func (r *reviewRepository) SaveStreetSnapFromDraft(ctx context.Context, draftID uint32) (uint32, error) {
	var draft model.StreetSnapDraft
	if err := r.db.WithContext(ctx).Where("id = ? AND is_deleted = 0", draftID).First(&draft).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return 0, ErrNotFound
		}
		return 0, err
	}
	curImgs, err := r.StreetDraftImages(ctx, draftID)
	if err != nil {
		return 0, err
	}
	sibImgs, err := r.streetApprovedSiblingImages(ctx, draftID, draft.City, draft.Year)
	if err != nil {
		return 0, err
	}
	imgs := unionStreetDraftImages(curImgs, sibImgs)

	now := uint32(time.Now().Unix())
	var snapID uint32
	err = r.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
		var existing model.StreetSnap
		if eErr := tx.Where("city = ? AND year = ? AND is_deleted = 0", draft.City, draft.Year).
			Limit(1).Find(&existing).Error; eErr != nil {
			return eErr
		}

		common := map[string]any{
			"title":       draft.Title,
			"year":        draft.Year,
			"city":        draft.City,
			"cover":       draft.Cover,
			"image_count": uint16(len(imgs)),
			"updated_at":  now,
		}

		if existing.ID != 0 {
			snapID = existing.ID
			if uErr := tx.Model(&model.StreetSnap{}).Where("id = ?", snapID).Updates(common).Error; uErr != nil {
				return uErr
			}
		} else {
			snap := &model.StreetSnap{
				Title:      draft.Title,
				Year:       draft.Year,
				City:       draft.City,
				Cover:      draft.Cover,
				ImageCount: uint16(len(imgs)),
				CreatedAt:  now,
				UpdatedAt:  now,
			}
			if cErr := tx.Create(snap).Error; cErr != nil {
				return cErr
			}
			snapID = snap.ID
		}

		// 替换图片：软删旧 + 重建
		if dErr := tx.Model(&model.StreetSnapImage{}).
			Where("snap_id = ? AND is_deleted = 0", snapID).
			Updates(map[string]any{"is_deleted": 1, "updated_at": now}).Error; dErr != nil {
			return dErr
		}
		if len(imgs) > 0 {
			rows := make([]model.StreetSnapImage, 0, len(imgs))
			for i, im := range imgs {
				rows = append(rows, model.StreetSnapImage{
					SnapID:      snapID,
					Image:       im.Image,
					Name:        im.Name,
					SortOrder:   uint32(i + 1),
					Phash:       im.Phash,
					IsDuplicate: im.IsDuplicate,
					DupOf:       im.DupOf,
					CreatedAt:   now,
					UpdatedAt:   now,
				})
			}
			if cErr := tx.Create(&rows).Error; cErr != nil {
				return cErr
			}
		}
		return nil
	})
	if err != nil {
		return 0, err
	}
	return snapID, nil
}

// runwayApprovedSiblingImages 返回同实体（品牌+季节码+系列）且已 approved 的其他草稿的图片，
// 用于多来源聚合：当前正被审核的草稿强制纳入，其余仅合并已审核来源，避免未审图泄露进正式表。
func (r *reviewRepository) runwayApprovedSiblingImages(ctx context.Context, excludeDraftID, brandID uint32, seasonCode, collectionType string) ([]model.BrandRunwayDraftImage, error) {
	var drafts []model.BrandRunwayDraft
	if err := r.db.WithContext(ctx).
		Where("brand_id = ? AND season_code = ? AND collection_type = ? AND status = ? AND is_deleted = 0 AND id <> ?", brandID, seasonCode, collectionType, model.DraftStatusApproved, excludeDraftID).
		Find(&drafts).Error; err != nil {
		return nil, err
	}
	out := make([]model.BrandRunwayDraftImage, 0)
	for _, d := range drafts {
		imgs, err := r.DraftImages(ctx, d.ID)
		if err != nil {
			return nil, err
		}
		out = append(out, imgs...)
	}
	return out, nil
}

// unionRunwayDraftImages 按 image URL 去重合并（七牛 key 已是 sha1，同图 URL 必相同）。当前草稿图优先。
func unionRunwayDraftImages(a, b []model.BrandRunwayDraftImage) []model.BrandRunwayDraftImage {
	seen := make(map[string]struct{}, len(a)+len(b))
	out := make([]model.BrandRunwayDraftImage, 0, len(a)+len(b))
	for _, im := range a {
		if _, ok := seen[im.Image]; ok {
			continue
		}
		seen[im.Image] = struct{}{}
		out = append(out, im)
	}
	for _, im := range b {
		if _, ok := seen[im.Image]; ok {
			continue
		}
		seen[im.Image] = struct{}{}
		out = append(out, im)
	}
	return out
}

// streetApprovedSiblingImages 同 city+year 已 approved 的其他街拍草稿图（多来源聚合）。
func (r *reviewRepository) streetApprovedSiblingImages(ctx context.Context, excludeDraftID uint32, city string, year uint16) ([]model.StreetSnapDraftImage, error) {
	var drafts []model.StreetSnapDraft
	if err := r.db.WithContext(ctx).
		Where("city = ? AND year = ? AND status = ? AND is_deleted = 0 AND id <> ?", city, year, model.DraftStatusApproved, excludeDraftID).
		Find(&drafts).Error; err != nil {
		return nil, err
	}
	out := make([]model.StreetSnapDraftImage, 0)
	for _, d := range drafts {
		imgs, err := r.StreetDraftImages(ctx, d.ID)
		if err != nil {
			return nil, err
		}
		out = append(out, imgs...)
	}
	return out, nil
}

// unionStreetDraftImages 按 image URL 去重合并。当前草稿图优先。
func unionStreetDraftImages(a, b []model.StreetSnapDraftImage) []model.StreetSnapDraftImage {
	seen := make(map[string]struct{}, len(a)+len(b))
	out := make([]model.StreetSnapDraftImage, 0, len(a)+len(b))
	for _, im := range a {
		if _, ok := seen[im.Image]; ok {
			continue
		}
		seen[im.Image] = struct{}{}
		out = append(out, im)
	}
	for _, im := range b {
		if _, ok := seen[im.Image]; ok {
			continue
		}
		seen[im.Image] = struct{}{}
		out = append(out, im)
	}
	return out
}

// ── 草稿图片删除 ────────────────────────────────────────────────────────────────

// SoftDeleteRunwayDraftImage 软删单张走秀草稿图片（审核阶段剔除坏图），并同步草稿 image_count。
// 不删七牛文件（与正式表 DeleteRunwayImage 行为一致：仅 DB 标记，避免误删被引用文件）。
func (r *reviewRepository) SoftDeleteRunwayDraftImage(ctx context.Context, draftID, imgID uint32) error {
	if err := r.db.WithContext(ctx).
		Model(&model.BrandRunwayDraftImage{}).
		Where("id = ? AND draft_id = ? AND is_deleted = 0", imgID, draftID).
		Updates(map[string]any{"is_deleted": 1, "updated_at": uint32(time.Now().Unix())}).Error; err != nil {
		return err
	}
	return r.db.WithContext(ctx).
		Exec("UPDATE brand_runway_draft SET image_count = GREATEST(image_count - 1, 0) WHERE id = ?", draftID).Error
}

// SoftDeleteStreetDraftImage 软删单张街拍草稿图片，并同步 image_count。
func (r *reviewRepository) SoftDeleteStreetDraftImage(ctx context.Context, draftID, imgID uint32) error {
	if err := r.db.WithContext(ctx).
		Model(&model.StreetSnapDraftImage{}).
		Where("id = ? AND draft_id = ? AND is_deleted = 0", imgID, draftID).
		Updates(map[string]any{"is_deleted": 1, "updated_at": uint32(time.Now().Unix())}).Error; err != nil {
		return err
	}
	return r.db.WithContext(ctx).
		Exec("UPDATE street_snap_draft SET image_count = GREATEST(image_count - 1, 0) WHERE id = ?", draftID).Error
}

// GetDraftImageKey 取单张草稿图片的七牛 key（删除前清理用）；不存在返回空串。
// kind 决定查哪张草稿图片表（runway / street）；未知 kind 返回 ErrNotFound。
func (r *reviewRepository) GetDraftImageKey(ctx context.Context, kind string, draftID, imgID uint32) (string, error) {
	switch kind {
	case dto.IngestKindRunway:
		var im model.BrandRunwayDraftImage
		err := r.db.WithContext(ctx).Where("id = ? AND draft_id = ?", imgID, draftID).First(&im).Error
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return "", nil
		}
		if err != nil {
			return "", err
		}
		return im.Image, nil
	case dto.IngestKindStreet:
		var im model.StreetSnapDraftImage
		err := r.db.WithContext(ctx).Where("id = ? AND draft_id = ?", imgID, draftID).First(&im).Error
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return "", nil
		}
		if err != nil {
			return "", err
		}
		return im.Image, nil
	default:
		return "", ErrNotFound
	}
}