package handler

import (
	"net/http"
	"strconv"
	"strings"

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

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

// BookAllChapters GET /api/book/all-chapters 返回所有章节（列表，来自 chapters 表）
func BookAllChapters(c *gin.Context) {
	var list []model.Chapter
	if err := database.DB().Order("sort_order ASC, id ASC").Find(&list).Error; err != nil {
		c.JSON(http.StatusOK, gin.H{"success": true, "data": []interface{}{}})
		return
	}
	c.JSON(http.StatusOK, gin.H{"success": true, "data": list})
}

// BookChapterByID GET /api/book/chapter/:id  按业务 id 查询（兼容旧链接）
func BookChapterByID(c *gin.Context) {
	id := c.Param("id")
	if id == "" {
		c.JSON(http.StatusBadRequest, gin.H{"success": false, "error": "缺少 id"})
		return
	}
	findChapterAndRespond(c, func(db *gorm.DB) *gorm.DB {
		return db.Where("id = ?", id)
	})
}

// BookChapterByMID GET /api/book/chapter/by-mid/:mid  按自增主键 mid 查询（新链接推荐）
func BookChapterByMID(c *gin.Context) {
	midStr := c.Param("mid")
	if midStr == "" {
		c.JSON(http.StatusBadRequest, gin.H{"success": false, "error": "缺少 mid"})
		return
	}
	mid, err := strconv.Atoi(midStr)
	if err != nil || mid < 1 {
		c.JSON(http.StatusBadRequest, gin.H{"success": false, "error": "mid 必须为正整数"})
		return
	}
	findChapterAndRespond(c, func(db *gorm.DB) *gorm.DB {
		return db.Where("mid = ?", mid)
	})
}

// findChapterAndRespond 按条件查章节并返回统一格式
func findChapterAndRespond(c *gin.Context, whereFn func(*gorm.DB) *gorm.DB) {
	var ch model.Chapter
	db := database.DB()
	if err := whereFn(db).First(&ch).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			c.JSON(http.StatusNotFound, gin.H{"success": false, "error": "章节不存在"})
			return
		}
		c.JSON(http.StatusOK, gin.H{"success": false, "error": err.Error()})
		return
	}
	out := gin.H{
		"success":      true,
		"data":         ch,
		"content":      ch.Content,
		"chapterTitle": ch.ChapterTitle,
		"partTitle":    ch.PartTitle,
		"id":           ch.ID,
		"mid":          ch.MID,
		"sectionTitle": ch.SectionTitle,
	}
	if ch.IsFree != nil {
		out["isFree"] = *ch.IsFree
	}
	if ch.Price != nil {
		out["price"] = *ch.Price
	}
	c.JSON(http.StatusOK, out)
}

// BookChapters GET/POST/PUT/DELETE /api/book/chapters（与 app/api/book/chapters 一致，用 GORM）
func BookChapters(c *gin.Context) {
	db := database.DB()
	switch c.Request.Method {
	case http.MethodGet:
		partId := c.Query("partId")
		status := c.Query("status")
		if status == "" {
			status = "published"
		}
		page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
		pageSize, _ := strconv.Atoi(c.DefaultQuery("pageSize", "100"))
		if page < 1 {
			page = 1
		}
		if pageSize < 1 || pageSize > 500 {
			pageSize = 100
		}
		q := db.Model(&model.Chapter{})
		if partId != "" {
			q = q.Where("part_id = ?", partId)
		}
		if status != "" && status != "all" {
			q = q.Where("status = ?", status)
		}
		var total int64
		q.Count(&total)
		var list []model.Chapter
		q.Order("sort_order ASC, id ASC").Offset((page - 1) * pageSize).Limit(pageSize).Find(&list)
		totalPages := int(total) / pageSize
		if int(total)%pageSize > 0 {
			totalPages++
		}
		c.JSON(http.StatusOK, gin.H{
			"success": true,
			"data": gin.H{
				"list": list, "total": total, "page": page, "pageSize": pageSize, "totalPages": totalPages,
			},
		})
		return
	case http.MethodPost:
		var body model.Chapter
		if err := c.ShouldBindJSON(&body); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"success": false, "error": "请求体无效"})
			return
		}
		if body.ID == "" || body.PartID == "" || body.ChapterID == "" {
			c.JSON(http.StatusBadRequest, gin.H{"success": false, "error": "缺少必要字段 id/partId/chapterId"})
			return
		}
		if err := db.Create(&body).Error; err != nil {
			c.JSON(http.StatusOK, gin.H{"success": false, "error": err.Error()})
			return
		}
		c.JSON(http.StatusOK, gin.H{"success": true, "data": body})
		return
	case http.MethodPut:
		var body model.Chapter
		if err := c.ShouldBindJSON(&body); err != nil || body.ID == "" {
			c.JSON(http.StatusBadRequest, gin.H{"success": false, "error": "缺少 id"})
			return
		}
		if err := db.Model(&model.Chapter{}).Where("id = ?", body.ID).Updates(map[string]interface{}{
			"part_title": body.PartTitle, "chapter_title": body.ChapterTitle, "section_title": body.SectionTitle,
			"content": body.Content, "word_count": body.WordCount, "is_free": body.IsFree, "price": body.Price,
			"sort_order": body.SortOrder, "status": body.Status,
		}).Error; err != nil {
			c.JSON(http.StatusOK, gin.H{"success": false, "error": err.Error()})
			return
		}
		c.JSON(http.StatusOK, gin.H{"success": true})
		return
	case http.MethodDelete:
		id := c.Query("id")
		if id == "" {
			c.JSON(http.StatusBadRequest, gin.H{"success": false, "error": "缺少 id"})
			return
		}
		if err := 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})
		return
	}
	c.JSON(http.StatusOK, gin.H{"success": false, "error": "不支持的请求方法"})
}

// BookHot GET /api/book/hot
func BookHot(c *gin.Context) {
	var list []model.Chapter
	database.DB().Order("sort_order ASC, id ASC").Limit(10).Find(&list)
	c.JSON(http.StatusOK, gin.H{"success": true, "data": list})
}

// BookLatestChapters GET /api/book/latest-chapters
func BookLatestChapters(c *gin.Context) {
	var list []model.Chapter
	database.DB().Order("updated_at DESC, id ASC").Limit(20).Find(&list)
	c.JSON(http.StatusOK, gin.H{"success": true, "data": list})
}

func escapeLikeBook(s string) string {
	s = strings.ReplaceAll(s, "\\", "\\\\")
	s = strings.ReplaceAll(s, "%", "\\%")
	s = strings.ReplaceAll(s, "_", "\\_")
	return s
}

// BookSearch GET /api/book/search?q= 章节搜索（与 /api/search 逻辑一致）
func BookSearch(c *gin.Context) {
	q := strings.TrimSpace(c.Query("q"))
	if q == "" {
		c.JSON(http.StatusOK, gin.H{"success": true, "results": []interface{}{}, "total": 0, "keyword": ""})
		return
	}
	pattern := "%" + escapeLikeBook(q) + "%"
	var list []model.Chapter
	err := database.DB().Model(&model.Chapter{}).
		Where("section_title LIKE ? OR content LIKE ?", pattern, pattern).
		Order("sort_order ASC, id ASC").
		Limit(20).
		Find(&list).Error
	if err != nil {
		c.JSON(http.StatusOK, gin.H{"success": true, "results": []interface{}{}, "total": 0, "keyword": q})
		return
	}
	lowerQ := strings.ToLower(q)
	results := make([]gin.H, 0, len(list))
	for _, ch := range list {
		matchType := "content"
		if strings.Contains(strings.ToLower(ch.SectionTitle), lowerQ) {
			matchType = "title"
		}
		results = append(results, gin.H{
			"id": ch.ID, "mid": ch.MID, "title": ch.SectionTitle, "part": ch.PartTitle, "chapter": ch.ChapterTitle,
			"isFree": ch.IsFree, "matchType": matchType,
		})
	}
	c.JSON(http.StatusOK, gin.H{"success": true, "results": results, "total": len(results), "keyword": q})
}

// BookStats GET /api/book/stats
func BookStats(c *gin.Context) {
	var total int64
	database.DB().Model(&model.Chapter{}).Count(&total)
	c.JSON(http.StatusOK, gin.H{"success": true, "data": gin.H{"totalChapters": total}})
}

// BookSync GET/POST /api/book/sync
func BookSync(c *gin.Context) {
	c.JSON(http.StatusOK, gin.H{"success": true, "message": "同步由 DB 维护"})
}