package handler

import (
	"context"
	"net/http"

	"soul-api/internal/database"
	"soul-api/internal/model"

	"github.com/gin-gonic/gin"
	"gorm.io/gorm"
)

// listSelectCols 列表/导出不加载 content，大幅加速
var listSelectCols = []string{
	"id", "section_title", "price", "is_free", "is_new",
	"part_id", "part_title", "chapter_id", "chapter_title", "sort_order",
}

// sectionListItem 与前端 SectionListItem 一致（小写驼峰）
type sectionListItem struct {
	ID           string   `json:"id"`
	Title        string   `json:"title"`
	Price        float64  `json:"price"`
	IsFree       *bool    `json:"isFree,omitempty"`
	IsNew        *bool    `json:"isNew,omitempty"` // stitch_soul：标记最新新增
	PartID       string   `json:"partId"`
	PartTitle    string   `json:"partTitle"`
	ChapterID    string   `json:"chapterId"`
	ChapterTitle string   `json:"chapterTitle"`
	FilePath     *string  `json:"filePath,omitempty"`
}

// DBBookAction GET/POST/PUT /api/db/book
func DBBookAction(c *gin.Context) {
	db := database.DB()
	switch c.Request.Method {
	case http.MethodGet:
		action := c.Query("action")
		id := c.Query("id")
		switch action {
		case "list":
			var rows []model.Chapter
			if err := db.Select(listSelectCols).Order("sort_order ASC, id ASC").Find(&rows).Error; err != nil {
				c.JSON(http.StatusOK, gin.H{"success": false, "error": err.Error(), "sections": []sectionListItem{}})
				return
			}
			sections := make([]sectionListItem, 0, len(rows))
			for _, r := range rows {
				price := 1.0
				if r.Price != nil {
					price = *r.Price
				}
				sections = append(sections, sectionListItem{
					ID:           r.ID,
					Title:        r.SectionTitle,
					Price:        price,
					IsFree:       r.IsFree,
					IsNew:        r.IsNew,
					PartID:       r.PartID,
					PartTitle:    r.PartTitle,
					ChapterID:    r.ChapterID,
					ChapterTitle: r.ChapterTitle,
				})
			}
			c.JSON(http.StatusOK, gin.H{"success": true, "sections": sections, "total": len(sections)})
			return
		case "read":
			if id == "" {
				c.JSON(http.StatusOK, gin.H{"success": false, "error": "缺少 id"})
				return
			}
			var ch model.Chapter
			if err := db.Where("id = ?", id).First(&ch).Error; err != nil {
				if err == gorm.ErrRecordNotFound {
					c.JSON(http.StatusOK, gin.H{"success": false, "error": "章节不存在"})
					return
				}
				c.JSON(http.StatusOK, gin.H{"success": false, "error": err.Error()})
				return
			}
			price := 1.0
			if ch.Price != nil {
				price = *ch.Price
			}
			c.JSON(http.StatusOK, gin.H{
				"success": true,
				"section": gin.H{
					"id":       ch.ID,
					"title":    ch.SectionTitle,
					"price":    price,
					"content":  ch.Content,
					"isNew":    ch.IsNew,
					"partId":   ch.PartID,
					"partTitle": ch.PartTitle,
					"chapterId": ch.ChapterID,
					"chapterTitle": ch.ChapterTitle,
				},
			})
			return
		case "export":
			var rows []model.Chapter
			if err := db.Select(listSelectCols).Order("sort_order ASC, id ASC").Find(&rows).Error; err != nil {
				c.JSON(http.StatusOK, gin.H{"success": false, "error": err.Error()})
				return
			}
			sections := make([]sectionListItem, 0, len(rows))
			for _, r := range rows {
				price := 1.0
				if r.Price != nil {
					price = *r.Price
				}
				sections = append(sections, sectionListItem{
					ID: r.ID, Title: r.SectionTitle, Price: price, IsFree: r.IsFree, IsNew: r.IsNew,
					PartID: r.PartID, PartTitle: r.PartTitle, ChapterID: r.ChapterID, ChapterTitle: r.ChapterTitle,
				})
			}
			c.JSON(http.StatusOK, gin.H{"success": true, "sections": sections})
			return
		default:
			c.JSON(http.StatusOK, gin.H{"success": false, "error": "无效的 action"})
			return
		}
	case http.MethodPost:
		var body struct {
			Action string        `json:"action"`
			Data   []importItem  `json:"data"`
		}
		if err := c.ShouldBindJSON(&body); err != nil {
			c.JSON(http.StatusOK, gin.H{"success": false, "error": "请求体无效"})
			return
		}
		switch body.Action {
		case "sync":
			c.JSON(http.StatusOK, gin.H{"success": true, "message": "同步完成（Gin 无文件源时可从 DB 已存在数据视为已同步）"})
			return
		case "import":
			imported, failed := 0, 0
			for _, item := range body.Data {
				price := 1.0
				if item.Price != nil {
					price = *item.Price
				}
				isFree := false
				if item.IsFree != nil {
					isFree = *item.IsFree
				}
				wordCount := len(item.Content)
				status := "published"
				ch := model.Chapter{
					ID:           item.ID,
					PartID:       strPtr(item.PartID, "part-1"),
					PartTitle:    strPtr(item.PartTitle, "未分类"),
					ChapterID:    strPtr(item.ChapterID, "chapter-1"),
					ChapterTitle: strPtr(item.ChapterTitle, "未分类"),
					SectionTitle: item.Title,
					Content:      item.Content,
					WordCount:    &wordCount,
					IsFree:       &isFree,
					Price:        &price,
					Status:       &status,
				}
				err := db.Where("id = ?", item.ID).First(&model.Chapter{}).Error
				if err == gorm.ErrRecordNotFound {
					err = db.Create(&ch).Error
				} else if err == nil {
					err = db.Model(&model.Chapter{}).Where("id = ?", item.ID).Updates(map[string]interface{}{
						"section_title": ch.SectionTitle,
						"content":       ch.Content,
						"word_count":   ch.WordCount,
						"is_free":      ch.IsFree,
						"price":        ch.Price,
					}).Error
				}
				if err != nil {
					failed++
					continue
				}
				imported++
			}
			c.JSON(http.StatusOK, gin.H{"success": true, "message": "导入完成", "imported": imported, "failed": failed})
			return
		default:
			c.JSON(http.StatusOK, gin.H{"success": false, "error": "无效的 action"})
			return
		}
	case http.MethodPut:
		var body struct {
			Action string `json:"action"`
			// reorder：新顺序，支持跨篇跨章时附带 partId/chapterId
			IDs  []string      `json:"ids"`
			Items []reorderItem `json:"items"`
			ID    string       `json:"id"`
			Title           string   `json:"title"`
			Content         string   `json:"content"`
			Price           *float64 `json:"price"`
			IsFree          *bool    `json:"isFree"`
			IsNew           *bool    `json:"isNew"` // stitch_soul：标记最新新增
			EditionStandard *bool    `json:"editionStandard"` // 是否属于普通版
			EditionPremium  *bool    `json:"editionPremium"`  // 是否属于增值版
		}
		if err := c.ShouldBindJSON(&body); err != nil {
			c.JSON(http.StatusOK, gin.H{"success": false, "error": "请求体无效"})
			return
		}
		if body.Action == "reorder" {
			// 立即返回成功，后台异步执行排序更新
			if len(body.Items) > 0 {
				items := make([]reorderItem, len(body.Items))
				copy(items, body.Items)
				c.JSON(http.StatusOK, gin.H{"success": true})
				go func() {
					db := database.DB()
					for i, it := range items {
						if it.ID == "" {
							continue
						}
						up := map[string]interface{}{"sort_order": i}
						if it.PartID != "" {
							up["part_id"] = it.PartID
						}
						if it.PartTitle != "" {
							up["part_title"] = it.PartTitle
						}
						if it.ChapterID != "" {
							up["chapter_id"] = it.ChapterID
						}
						if it.ChapterTitle != "" {
							up["chapter_title"] = it.ChapterTitle
						}
						_ = db.WithContext(context.Background()).Model(&model.Chapter{}).Where("id = ?", it.ID).Updates(up).Error
					}
				}()
				return
			}
			if len(body.IDs) > 0 {
				ids := make([]string, len(body.IDs))
				copy(ids, body.IDs)
				c.JSON(http.StatusOK, gin.H{"success": true})
				go func() {
					db := database.DB()
					for i, id := range ids {
						if id != "" {
							_ = db.WithContext(context.Background()).Model(&model.Chapter{}).Where("id = ?", id).Update("sort_order", i).Error
						}
					}
				}()
				return
			}
		}
		if body.ID == "" {
			c.JSON(http.StatusOK, gin.H{"success": false, "error": "缺少 id"})
			return
		}
		price := 1.0
		if body.Price != nil {
			price = *body.Price
		}
		isFree := false
		if body.IsFree != nil {
			isFree = *body.IsFree
		}
		wordCount := len(body.Content)
		updates := map[string]interface{}{
			"section_title": body.Title,
			"content":       body.Content,
			"word_count":    wordCount,
			"price":         price,
			"is_free":       isFree,
		}
		if body.IsNew != nil {
			updates["is_new"] = *body.IsNew
		}
		if body.EditionStandard != nil {
			updates["edition_standard"] = *body.EditionStandard
		}
		if body.EditionPremium != nil {
			updates["edition_premium"] = *body.EditionPremium
		}
		err := db.Model(&model.Chapter{}).Where("id = ?", body.ID).Updates(updates).Error
		if err != nil {
			c.JSON(http.StatusOK, gin.H{"success": false, "error": err.Error()})
			return
		}
		c.JSON(http.StatusOK, gin.H{"success": true})
		return
	}
	c.JSON(http.StatusOK, gin.H{"success": false, "error": "不支持的请求方法"})
}

type reorderItem struct {
	ID           string `json:"id"`
	PartID       string `json:"partId"`
	PartTitle    string `json:"partTitle"`
	ChapterID    string `json:"chapterId"`
	ChapterTitle string `json:"chapterTitle"`
}

type importItem struct {
	ID           string   `json:"id"`
	Title        string   `json:"title"`
	Content      string   `json:"content"`
	Price        *float64 `json:"price"`
	IsFree       *bool    `json:"isFree"`
	PartID       *string  `json:"partId"`
	PartTitle    *string  `json:"partTitle"`
	ChapterID    *string  `json:"chapterId"`
	ChapterTitle *string  `json:"chapterTitle"`
}

func strPtr(s *string, def string) string {
	if s != nil && *s != "" {
		return *s
	}
	return def
}

// DBBookDelete DELETE /api/db/book
func DBBookDelete(c *gin.Context) {
	id := c.Query("id")
	if id == "" {
		c.JSON(http.StatusOK, gin.H{"success": false, "error": "缺少 id"})
		return
	}
	if err := database.DB().Where("id = ?", id).Delete(&model.Chapter{}).Error; err != nil {
		c.JSON(http.StatusOK, gin.H{"success": false, "error": err.Error()})
		return
	}
	c.JSON(http.StatusOK, gin.H{"success": true})
}