package handlers

import (
	"math"
	"net/http"
	"strconv"
	"time"

	"goblog/config"
	"goblog/database"
	"goblog/models"

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

// getConfig 获取全局配置（启动时已初始化，直接返回）
func getConfig() *config.Config {
	if cfg := config.GetGlobalConfig(); cfg != nil {
		return cfg
	}
	return config.Load()
}

// loadSiteInfo 加载站点名称和描述（优先数据库，回退配置文件）
func loadSiteInfo(cfg *config.Config) (siteName, siteDesc string) {
	siteName = cfg.App.Name
	siteDesc = cfg.App.Description
	if v, err := models.GetOptionValue(database.DB, OptionSiteName, 0); err == nil && v != "" {
		siteName = v
	}
	if v, err := models.GetOptionValue(database.DB, OptionSiteDesc, 0); err == nil && v != "" {
		siteDesc = v
	}
	return
}

// loadPublishedPages 加载所有已发布页面（按排序）
func loadPublishedPages() []models.Page {
	var pages []models.Page
	database.DB.Where("status = ?", "published").Order("`order` ASC").Find(&pages)
	return pages
}

// loadSidebarData 加载侧边栏数据
func loadSidebarData() (categories []models.Category, tags []models.Tag, postCount, categoryCount, tagCount int64) {
	database.DB.Order("name ASC").Find(&categories)
	database.DB.Order("name ASC").Find(&tags)
	database.DB.Model(&models.Post{}).Where("status = ?", "published").Count(&postCount)
	database.DB.Model(&models.Category{}).Count(&categoryCount)
	database.DB.Model(&models.Tag{}).Count(&tagCount)
	return
}

// loginInfo 从上下文提取登录态信息（供侧边栏系统菜单区分已登录/未登录）
func loginInfo(c *gin.Context) (isLoggedIn bool, loginName string) {
	if _, ok := c.Get("userID"); !ok {
		return false, ""
	}
	name, _ := c.Get("username")
	loginName, _ = name.(string)
	return true, loginName
}

// 首页
type IndexData struct {
	Title       string
	SiteName    string
	SiteDesc    string
	Description string
	Posts       []models.Post
	Pages       []models.Page
	CurrentPage int
	TotalPages  int
	Year        int
	// Sidebar 数据
	Categories    []models.Category
	Tags          []models.Tag
	PostCount     int64
	CategoryCount int64
	TagCount      int64
	// 登录态（侧边栏系统菜单用）
	IsLoggedIn bool
	LoginName  string
}

func IndexView(c *gin.Context) {
	cfg := getConfig()
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	if page < 1 {
		page = 1
	}
	pageSize := 10

	categoryID, _ := strconv.Atoi(c.Query("category"))
	tagID, _ := strconv.Atoi(c.Query("tag"))

	db := database.DB.Model(&models.Post{}).Preload("Category").Preload("Tags").Preload("Author").
		Where("status = ?", "published")

	userId, exists := c.Get("userID")

	if exists {
		db = db.Or("author_id = ?", userId)
	}

	if categoryID > 0 {
		db = db.Where("category_id = ?", categoryID)
	}
	if tagID > 0 {
		db = db.Joins("JOIN post_tags ON post_tags.post_id = posts.id").
			Where("post_tags.tag_id = ?", tagID)
	}

	var total int64
	db.Count(&total)

	var posts []models.Post
	offset := (page - 1) * pageSize
	db.Order("is_top DESC, published_at DESC, created_at DESC").
		Offset(offset).Limit(pageSize).Find(&posts)

	totalPages := int(math.Ceil(float64(total) / float64(pageSize)))
	categories, tags, postCount, categoryCount, tagCount := loadSidebarData()
	siteName, siteDesc := loadSiteInfo(cfg)
	pages := loadPublishedPages()

	data := IndexData{
		Title:       "首页",
		SiteName:    siteName,
		SiteDesc:    siteDesc,
		Description: siteDesc,
		Posts:       posts,
		Pages:       pages,
		CurrentPage: page,
		TotalPages:  totalPages,
		Year:        time.Now().Year(),
		// Sidebar 数据
		Categories:    categories,
		Tags:          tags,
		PostCount:     postCount,
		CategoryCount: categoryCount,
		TagCount:      tagCount,
	}
	data.IsLoggedIn, data.LoginName = loginInfo(c)

	c.HTML(http.StatusOK, "index", data)
}

// 文章详情页
type PostDetailData struct {
	Title        string
	SiteName     string
	SiteDesc     string
	Description  string
	Post         models.Post
	Pages        []models.Page
	Comments     []models.Comment
	CommentCount int64
	Year         int
	PrevPost     *models.Post // 上一篇
	NextPost     *models.Post // 下一篇
	// 评论展示设置与分页
	ShowComments      bool
	CommentPage       int
	CommentTotalPages int
	// Sidebar 数据
	Categories    []models.Category
	Tags          []models.Tag
	PostCount     int64
	CategoryCount int64
	TagCount      int64
	// 登录态（侧边栏系统菜单用）
	IsLoggedIn bool
	LoginName  string
}

func PostView(c *gin.Context) {
	cfg := getConfig()
	slug := c.Param("slug")

	var post models.Post
	query := database.DB.Preload("Category").Preload("Tags").Preload("Author").
		Where("status = ?", "published").
		Session(&gorm.Session{}) // 创建可安全复用的查询会话，避免两次查询条件叠加

	err := query.Where("slug = ?", slug).First(&post).Error
	// slug 未命中时，若参数为纯数字则回退按文章 ID 查询（兼容 /post/17 形式的链接）
	if err != nil {
		if id, convErr := strconv.Atoi(slug); convErr == nil {
			err = query.Where("id = ?", id).First(&post).Error
		}
	}

	if err != nil {
		c.HTML(http.StatusNotFound, "index", gin.H{
			"Title":    "404 - 页面不存在",
			"SiteName": cfg.App.Name,
			"Year":     time.Now().Year(),
		})
		return
	}

	// 增加浏览量
	database.DB.Model(&post).UpdateColumn("views", gorm.Expr("views + 1"))

	pages := loadPublishedPages()

	// 统计评论数
	var commentCount int64
	database.DB.Model(&models.Comment{}).Where("post_id = ? AND status = ?", post.ID, "approved").Count(&commentCount)

	// 读取评论展示设置
	showComments := true
	if v, optErr := models.GetOptionValue(database.DB, OptionShowComments, 0); optErr == nil {
		showComments = v != "0"
	}
	commentPageSize := 10
	if v, optErr := models.GetOptionValue(database.DB, OptionCommentPageSize, 0); optErr == nil {
		if n, convErr := strconv.Atoi(v); convErr == nil && n > 0 {
			commentPageSize = n
		}
	}

	// 顶级评论分页查询（回复随父评论一起展示，不单独分页）
	commentPage, _ := strconv.Atoi(c.DefaultQuery("cpage", "1"))
	if commentPage < 1 {
		commentPage = 1
	}
	var comments []models.Comment
	commentTotalPages := 0
	if showComments {
		var topCount int64
		database.DB.Model(&models.Comment{}).
			Where("post_id = ? AND status = ? AND parent_id IS NULL", post.ID, "approved").
			Count(&topCount)
		commentTotalPages = int(math.Ceil(float64(topCount) / float64(commentPageSize)))
		if commentTotalPages > 0 && commentPage > commentTotalPages {
			commentPage = commentTotalPages
		}
		database.DB.Where("post_id = ? AND status = ? AND parent_id IS NULL", post.ID, "approved").
			Preload("Children", func(db *gorm.DB) *gorm.DB {
				return db.Where("status = ?", "approved")
			}).
			Order("created_at ASC").
			Offset((commentPage - 1) * commentPageSize).Limit(commentPageSize).
			Find(&comments)
	}

	// 获取上一篇（发布时间更早的文章）
	var prevPost models.Post
	prevErr := database.DB.Where("status = ? AND published_at < ?", "published", post.PublishedAt).
		Order("published_at DESC").First(&prevPost).Error

	// 获取下一篇（发布时间更晚的文章）
	var nextPost models.Post
	nextErr := database.DB.Where("status = ? AND published_at > ?", "published", post.PublishedAt).
		Order("published_at ASC").First(&nextPost).Error

	siteName, siteDesc := loadSiteInfo(cfg)
	categories, tags, postCount, categoryCount, tagCount := loadSidebarData()

	data := PostDetailData{
		Title:        post.Title,
		SiteName:     siteName,
		SiteDesc:     siteDesc,
		Description:  post.Summary,
		Post:         post,
		Pages:        pages,
		Comments:     comments,
		CommentCount: commentCount,
		Year:         time.Now().Year(),
		// 评论展示设置与分页
		ShowComments:      showComments,
		CommentPage:       commentPage,
		CommentTotalPages: commentTotalPages,
		// Sidebar 数据
		Categories:    categories,
		Tags:          tags,
		PostCount:     postCount,
		CategoryCount: categoryCount,
		TagCount:      tagCount,
	}
	data.IsLoggedIn, data.LoginName = loginInfo(c)

	// 只有当查询成功时才赋值
	if prevErr == nil {
		data.PrevPost = &prevPost
	}
	if nextErr == nil {
		data.NextPost = &nextPost
	}

	c.HTML(http.StatusOK, "post", data)
}

// 独立页面
type PageDetailData struct {
	Title       string
	SiteName    string
	SiteDesc    string
	Description string
	Page        models.Page
	Pages       []models.Page
	Year        int
	// Sidebar 数据
	Categories    []models.Category
	Tags          []models.Tag
	PostCount     int64
	CategoryCount int64
	TagCount      int64
	// 登录态（侧边栏系统菜单用）
	IsLoggedIn bool
	LoginName  string
}

func PageView(c *gin.Context) {
	cfg := getConfig()
	slug := c.Param("slug")

	var page models.Page
	err := database.DB.Where("slug = ? AND status = ?", slug, "published").First(&page).Error
	if err != nil {
		c.HTML(http.StatusNotFound, "index", gin.H{
			"Title":    "404 - 页面不存在",
			"SiteName": cfg.App.Name,
			"Year":     time.Now().Year(),
		})
		return
	}

	pages := loadPublishedPages()
	siteName, siteDesc := loadSiteInfo(cfg)
	categories, tags, postCount, categoryCount, tagCount := loadSidebarData()

	data := PageDetailData{
		Title:       page.Title,
		SiteName:    siteName,
		SiteDesc:    siteDesc,
		Description: "",
		Page:        page,
		Pages:       pages,
		Year:        time.Now().Year(),
		// Sidebar 数据
		Categories:    categories,
		Tags:          tags,
		PostCount:     postCount,
		CategoryCount: categoryCount,
		TagCount:      tagCount,
	}
	data.IsLoggedIn, data.LoginName = loginInfo(c)

	c.HTML(http.StatusOK, "page", data)
}

// 提交评论（表单提交）
func SubmitComment(c *gin.Context) {
	postID, _ := strconv.Atoi(c.PostForm("post_id"))
	author := c.PostForm("author")
	email := c.PostForm("email")
	website := c.PostForm("website")
	content := c.PostForm("content")

	// 检查文章是否存在
	var post models.Post
	if err := database.DB.First(&post, postID).Error; err != nil {
		c.String(http.StatusBadRequest, "文章不存在")
		return
	}

	comment := models.Comment{
		PostID:  uint(postID),
		Author:  author,
		Email:   email,
		Website: website,
		Content: content,
		Status:  "pending",
	}

	if err := database.DB.Create(&comment).Error; err != nil {
		c.String(http.StatusInternalServerError, "提交失败")
		return
	}

	c.Redirect(http.StatusFound, "/post/"+post.Slug)
}

// 搜索结果页
func SearchView(c *gin.Context) {
	cfg := getConfig()

	keyword := c.Query("keyword")
	if keyword == "" {
		c.Redirect(http.StatusFound, "/")
		return
	}

	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	if page < 1 {
		page = 1
	}
	pageSize := 10

	db := database.DB.Model(&models.Post{}).Preload("Category").Preload("Tags").Preload("Author").
		Where("status = ?", "published").
		Where("title LIKE ? OR content LIKE ? OR summary LIKE ?",
			"%"+keyword+"%", "%"+keyword+"%", "%"+keyword+"%")

	var total int64
	db.Count(&total)

	var posts []models.Post
	offset := (page - 1) * pageSize
	db.Order("published_at DESC").
		Offset(offset).Limit(pageSize).Find(&posts)

	pages := loadPublishedPages()
	totalPages := int(math.Ceil(float64(total) / float64(pageSize)))
	categories, tags, postCount, categoryCount, tagCount := loadSidebarData()
	siteName, siteDesc := loadSiteInfo(cfg)

	data := IndexData{
		Title:         "搜索: " + keyword,
		SiteName:      siteName,
		SiteDesc:      siteDesc,
		Description:   "搜索关键词: " + keyword,
		Posts:         posts,
		Pages:         pages,
		CurrentPage:   page,
		TotalPages:    totalPages,
		Year:          time.Now().Year(),
		Categories:    categories,
		Tags:          tags,
		PostCount:     postCount,
		CategoryCount: categoryCount,
		TagCount:      tagCount,
	}
	data.IsLoggedIn, data.LoginName = loginInfo(c)

	c.HTML(http.StatusOK, "index", data)
}