// migrate_single_table 把历史草稿数据搬迁进正式表（单表发布模型的数据迁移，一次性执行）。
//
// 用法：
//
//	go run ./scripts/migrate_single_table -dry-run   # 只统计与校验，不写库
//	go run ./scripts/migrate_single_table            # 真正搬迁
//
// 搬迁规则：
//   - 正式表既有行：status 已由迁移 2026-09-22-01 置为 published，本脚本不动。
//   - pending / rejected 草稿：插入正式表并保留原状态，草稿图片插入正式图片表。
//   - approved 草稿：其内容当年已由「晋升」写入正式表，**不重复插入**，只丢弃元数据。
//   - 街拍副图：parent_image_id 从「草稿图片 id」改写为「新正式图片 id」；映射缺失则降级为主图。
//
// 校验不通过即中止（退出码 1），且不删任何数据；删草稿表由后续迁移人工执行。
package main

import (
	"context"
	"flag"
	"fmt"
	"log"

	"fashionapi/internal/config"
	"fashionapi/internal/database"
	"fashionapi/internal/model"

	"gorm.io/gorm"
)

func main() {
	dryRun := flag.Bool("dry-run", false, "只统计与校验，不写库")
	flag.Parse()

	cfg, err := config.Load("")
	if err != nil {
		log.Fatalf("加载配置失败: %v", err)
	}
	db, err := database.New(cfg.Database)
	if err != nil {
		log.Fatalf("连接数据库失败: %v", err)
	}
	defer database.Close(db)

	ctx := context.Background()
	if err := run(ctx, db, *dryRun); err != nil {
		log.Fatalf("搬迁失败: %v", err)
	}
	if *dryRun {
		fmt.Println("dry-run 结束：未写入任何数据")
	}
}

func run(ctx context.Context, db *gorm.DB, dryRun bool) error {
	// 1) 前置校验：每个 approved 草稿都必须能在正式表找到对应实体行，
	//    否则说明有「只存在于草稿」的内容，需要人工处理，不能盲目删表。
	var orphans int64
	if err := db.WithContext(ctx).Raw(`
SELECT count(*) FROM brand_runway_drafts d
WHERE d.status = 'approved' AND d.is_deleted = 0
  AND NOT EXISTS (
    SELECT 1 FROM brand_runways r
    WHERE r.brand_id = d.brand_id AND r.season_code = d.season_code
      AND r.collection_type = d.collection_type AND r.is_deleted = 0)`).Scan(&orphans).Error; err != nil {
		return fmt.Errorf("校验走秀孤儿草稿: %w", err)
	}
	if orphans > 0 {
		return fmt.Errorf("有 %d 条 approved 走秀草稿在正式表找不到对应记录，请人工处理后重跑", orphans)
	}
	if err := db.WithContext(ctx).Raw(`
SELECT count(*) FROM street_snap_drafts d
WHERE d.status = 'approved' AND d.is_deleted = 0
  AND NOT EXISTS (
    SELECT 1 FROM street_snaps s
    WHERE s.city = d.city AND s.year = d.year AND s.is_deleted = 0)`).Scan(&orphans).Error; err != nil {
		return fmt.Errorf("校验街拍孤儿草稿: %w", err)
	}
	if orphans > 0 {
		return fmt.Errorf("有 %d 条 approved 街拍草稿在正式表找不到对应记录，请人工处理后重跑", orphans)
	}

	total, err := migrateRunways(ctx, db, dryRun)
	if err != nil {
		return err
	}
	streetTotal, err := migrateStreets(ctx, db, dryRun)
	if err != nil {
		return err
	}
	fmt.Printf("搬迁完成：走秀草稿 %d 条，街拍草稿 %d 条\n", total, streetTotal)
	return nil
}

// migrateRunways 搬迁 pending / rejected 的走秀草稿（含图片），返回搬迁条数。
func migrateRunways(ctx context.Context, db *gorm.DB, dryRun bool) (int, error) {
	var drafts []model.BrandRunwayDraft
	if err := db.WithContext(ctx).
		Where("status IN ? AND is_deleted = 0", []string{model.StatusPending, model.StatusRejected}).
		Order("id ASC").Find(&drafts).Error; err != nil {
		return 0, err
	}
	fmt.Printf("走秀待搬迁草稿：%d 条\n", len(drafts))
	if dryRun {
		for _, d := range drafts {
			var n int64
			db.WithContext(ctx).Model(&model.BrandRunwayDraftImage{}).
				Where("draft_id = ? AND is_deleted = 0", d.ID).Count(&n)
			fmt.Printf("  draft=%d status=%s title=%q 图片=%d\n", d.ID, d.Status, d.TitleEn, n)
		}
		return len(drafts), nil
	}

	moved := 0
	for _, d := range drafts {
		err := db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
			rw := model.BrandRunway{
				JobID: d.JobID, BrandID: d.BrandID,
				TitleEn: d.TitleEn, TitleCn: d.TitleCn,
				DescriptionEn: d.DescriptionEn, DescriptionCn: d.DescriptionCn,
				Year: d.Year, Season: d.Season,
				CollectionType: d.CollectionType, SeasonCode: d.SeasonCode,
				Cover: d.Cover, ImageCount: d.ImageCount,
				Status: d.Status, Reviewer: d.Reviewer, RejectReason: d.RejectReason,
				IsDeleted: d.IsDeleted, CreatedAt: d.CreatedAt, UpdatedAt: d.UpdatedAt,
			}
			if cErr := tx.Create(&rw).Error; cErr != nil {
				return cErr
			}
			var imgs []model.BrandRunwayDraftImage
			if fErr := tx.Where("draft_id = ?", d.ID).Order("sort_order ASC, id ASC").Find(&imgs).Error; fErr != nil {
				return fErr
			}
			if len(imgs) == 0 {
				return nil
			}
			rows := make([]model.BrandRunwayImage, 0, len(imgs))
			for _, im := range imgs {
				rows = append(rows, model.BrandRunwayImage{
					RunwayID: rw.ID, BrandID: d.BrandID,
					Image: im.Image, Name: im.Name, SortOrder: im.SortOrder,
					LookIndex: im.LookIndex, IsDetail: im.IsDetail,
					IsDeleted: im.IsDeleted, Phash: im.Phash,
					IsDuplicate: im.IsDuplicate, DupOf: im.DupOf,
					CreatedAt: im.CreatedAt, UpdatedAt: im.UpdatedAt,
				})
			}
			return tx.Create(&rows).Error
		})
		if err != nil {
			return moved, fmt.Errorf("搬迁走秀草稿 %d: %w", d.ID, err)
		}
		moved++
	}
	return moved, nil
}

// migrateStreets 搬迁 pending / rejected 的街拍草稿，并改写副图父引用。
func migrateStreets(ctx context.Context, db *gorm.DB, dryRun bool) (int, error) {
	var drafts []model.StreetSnapDraft
	if err := db.WithContext(ctx).
		Where("status IN ? AND is_deleted = 0", []string{model.StatusPending, model.StatusRejected}).
		Order("id ASC").Find(&drafts).Error; err != nil {
		return 0, err
	}
	fmt.Printf("街拍待搬迁草稿：%d 条\n", len(drafts))
	if dryRun {
		for _, d := range drafts {
			var n int64
			db.WithContext(ctx).Model(&model.StreetSnapDraftImage{}).
				Where("draft_id = ? AND is_deleted = 0", d.ID).Count(&n)
			fmt.Printf("  draft=%d status=%s title=%q city=%s 图片=%d\n", d.ID, d.Status, d.Title, d.City, n)
		}
		return len(drafts), nil
	}

	moved := 0
	for _, d := range drafts {
		err := db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
			snap := model.StreetSnap{
				JobID: d.JobID, Title: d.Title, Year: d.Year, City: d.City,
				Cover: d.Cover, ImageCount: d.ImageCount,
				Status: d.Status, Reviewer: d.Reviewer, RejectReason: d.RejectReason,
				IsDeleted: d.IsDeleted, CreatedAt: d.CreatedAt, UpdatedAt: d.UpdatedAt,
			}
			if cErr := tx.Create(&snap).Error; cErr != nil {
				return cErr
			}
			var imgs []model.StreetSnapDraftImage
			if fErr := tx.Where("draft_id = ?", d.ID).Order("sort_order ASC, id ASC").Find(&imgs).Error; fErr != nil {
				return fErr
			}
			if len(imgs) == 0 {
				return nil
			}

			// 第一遍：插入主图，记下「草稿图片 id → 新正式图片 id」。
			idMap := make(map[uint32]uint32, len(imgs))
			mains := make([]model.StreetSnapImage, 0, len(imgs))
			for _, im := range imgs {
				if im.IsDetail == 1 {
					continue
				}
				mains = append(mains, model.StreetSnapImage{
					SnapID: snap.ID, Image: im.Image, Name: im.Name, SortOrder: im.SortOrder,
					IsDetail: 0, IsDeleted: im.IsDeleted, Phash: im.Phash,
					IsDuplicate: im.IsDuplicate, DupOf: im.DupOf,
					CreatedAt: im.CreatedAt, UpdatedAt: im.UpdatedAt,
				})
			}
			for i := range mains {
				if cErr := tx.Create(&mains[i]).Error; cErr != nil {
					return cErr
				}
			}
			mi := 0
			for _, im := range imgs {
				if im.IsDetail == 1 {
					continue
				}
				idMap[im.ID] = mains[mi].ID
				mi++
			}

			// 第二遍：插入副图并把父引用从小表 id 改写成新正式行 id；映射缺失则降级为主图。
			details := make([]model.StreetSnapImage, 0, len(imgs)-len(mains))
			for _, im := range imgs {
				if im.IsDetail != 1 {
					continue
				}
				row := model.StreetSnapImage{
					SnapID: snap.ID, Image: im.Image, Name: im.Name, SortOrder: im.SortOrder,
					IsDetail: 1, IsDeleted: im.IsDeleted, Phash: im.Phash,
					IsDuplicate: im.IsDuplicate, DupOf: im.DupOf,
					CreatedAt: im.CreatedAt, UpdatedAt: im.UpdatedAt,
				}
				if newParent, ok := idMap[im.ParentImageID]; ok {
					row.ParentImageID = newParent
				} else {
					row.IsDetail = 0 // 父行缺失：按主图渲染，与读侧容错一致
				}
				details = append(details, row)
			}
			if len(details) > 0 {
				if cErr := tx.Create(&details).Error; cErr != nil {
					return cErr
				}
			}
			return nil
		})
		if err != nil {
			return moved, fmt.Errorf("搬迁街拍草稿 %d: %w", d.ID, err)
		}
		moved++
	}
	return moved, nil
}