package router

import (
	"encoding/json"
	"html/template"
	"net/http"
	"os"
	"strings"
	"videoweb/app/api/web"
	"videoweb/app/appg"
	"videoweb/app/service/commentser"
	"videoweb/app/service/playletser"
	"videoweb/app/service/seoser"
	"videoweb/app/service/translationser"
	"videoweb/app/service/videoser"
	staticassets "videoweb/app/static"

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

// Init 初始化 Gin，注册静态资源与业务路由。
func Init() *gin.Engine {
	setGinMode()
	engine := gin.Default()
	engine.HandleMethodNotAllowed = true
	setupEngine(engine)
	registerM3U8Routes(engine)
	registerSitemapRoutes(engine)
	registerRoutes(engine)
	engine.NoMethod(web.NotFound)
	return engine
}

// DHInit 导航站独立端口：仅暴露官方导航页及静态资源。
func DHInit() *gin.Engine {
	setGinMode()
	engine := gin.Default()
	engine.HandleMethodNotAllowed = true
	setupEngine(engine)
	engine.GET("/", web.Nav)
	engine.GET("/nav/", web.Nav)
	engine.GET("/dh/", web.Nav)
	engine.NoRoute(web.NotFound)
	engine.NoMethod(web.NotFound)
	return engine
}

func setGinMode() {
	mode := strings.ToLower(strings.TrimSpace(appg.Conf.RunMod))
	if envMode := strings.ToLower(strings.TrimSpace(os.Getenv(gin.EnvGinMode))); envMode != "" {
		mode = envMode
	}
	switch mode {
	case "test":
		gin.SetMode(gin.TestMode)
	case "prod", "production", "release":
		gin.SetMode(gin.ReleaseMode)
	default:
		gin.SetMode(gin.DebugMode)
	}
}

func setupEngine(engine *gin.Engine) {
	tplFuncs := playletser.TemplateFuncs()
	for name, fn := range commentser.TemplateFuncs() {
		tplFuncs[name] = fn
	}
	tplFuncs["InJSONScript"] = inJSONScript
	tplFuncs["navHref"] = translationser.NavHref
	tplFuncs["navIsDownload"] = translationser.NavIsDownload
	tplFuncs["navIsActive"] = translationser.NavIsActive
	tplFuncs["navDrawerIcon"] = translationser.NavDrawerIcon
	tplFuncs["navHasMegaMenu"] = translationser.NavHasMegaMenu
	tplFuncs["listThemeSegment"] = translationser.ListThemeSegmentFromPath
	tplFuncs["listUpdateStatus"] = translationser.ListUpdateStatusFromPath
	tplFuncs["seriesListURL"] = videoser.SeriesListURL
	tplFuncs["videoDetailURL"] = videoser.VideoDetailURL
	tplFuncs["videoPlayURL"] = videoser.VideoPlayURL
	tplFuncs["mediaTypeLabel"] = videoser.MediaTypeLabel
	tplFuncs["episodeLabel"] = videoser.EpisodeLabel
	engine.SetFuncMap(tplFuncs)
	engine.SetHTMLTemplate(mustHTMLTemplate(tplFuncs))
	engine.Use(strictTransportSecurity(), staticCacheHeaders(), crawlerHeaders())
	engine.StaticFS("/static", http.FS(staticassets.FS))
}

// strictTransportSecurity 仅在请求实际通过 HTTPS 到达，或可信代理标记首个协议为 HTTPS 时启用 HSTS。
// 不声明 includeSubDomains/preload，避免把尚未确认支持 HTTPS 的子域一并纳入。
func strictTransportSecurity() gin.HandlerFunc {
	return func(c *gin.Context) {
		if isHTTPSRequest(c.Request) {
			c.Header("Strict-Transport-Security", "max-age=31536000")
		}
		c.Next()
	}
}

func isHTTPSRequest(r *http.Request) bool {
	if r == nil {
		return false
	}
	if r.TLS != nil {
		return true
	}
	proto := r.Header.Get("X-Forwarded-Proto")
	if i := strings.IndexByte(proto, ','); i >= 0 {
		proto = proto[:i]
	}
	return strings.EqualFold(strings.TrimSpace(proto), "https")
}

// crawlerHeaders 防止接口和媒体工具响应进入搜索索引。
func crawlerHeaders() gin.HandlerFunc {
	return func(c *gin.Context) {
		path := c.Request.URL.Path
		if strings.HasPrefix(path, "/api/") || strings.HasPrefix(path, "/h5/") ||
			path == "/enkey" || path == "/newenkey" || path == "/healthz" {
			c.Header("X-Robots-Tag", "noindex, nofollow")
		}
		c.Next()
	}
}

// inJSONScript 将任意数据序列化为可嵌入 <script> 的 JSON。
func inJSONScript(v any) template.JS {
	b, err := json.Marshal(v)
	if err != nil {
		return template.JS("null")
	}
	return template.JS(b)
}

// staticCacheHeaders 为静态资源设置浏览器缓存。
func staticCacheHeaders() gin.HandlerFunc {
	return func(c *gin.Context) {
		if strings.HasPrefix(c.Request.URL.Path, "/static/") {
			c.Header("Cache-Control", "public, max-age=604800, stale-while-revalidate=86400")
		}
		c.Next()
	}
}

func registerRoutes(r *gin.Engine) {
	// 页面路由与 template/pages 文件名对应：camelCase → kebab-case（如 popularRecommend → /popular-recommend）
	r.GET("/", web.Index)
	r.GET("/search-mobile", web.SearchMobile)
	r.GET("/search", web.Search)
	r.GET("/search/:q", web.Search)
	r.GET("/search/:q/page/:page", web.Search)
	r.GET("/about", web.About)
	r.GET("/help", web.Help)
	r.GET("/terms", web.Terms)
	r.GET("/privacy", web.Privacy)
	r.GET("/2257", web.Compliance2257)
	r.GET("/dmca", web.DMCA)
	r.GET("/download-app", web.DownloadApp)
	r.GET("/nav", web.Nav)
	r.GET("/nav/", web.Nav)
	r.GET("/dh", web.Nav)
	r.GET("/dh/", web.Nav)
	r.GET("/list", web.List)
	r.GET("/list/:theme", web.List)
	r.GET("/list/:theme/:updateStatus/:sortType", web.List)
	r.GET("/list/:theme/:updateStatus/:sortType/page/:page", web.List)
	r.GET("/more-list/:configId/:timeRange/:theme/page/:page", web.MoreList)
	r.GET("/more-list/:configId/:timeRange/:theme", web.MoreList)
	r.GET("/more-list/:configId/page/:page", web.MoreList)
	r.GET("/more-list/:configId", web.MoreList)
	r.GET("/more-series-list/:configId/:timeRange/:theme/page/:page", web.MoreSeriesList)
	r.GET("/more-series-list/:configId/:timeRange/:theme", web.MoreSeriesList)
	r.GET("/more-series-list/:configId/page/:page", web.MoreSeriesList)
	r.GET("/more-series-list/:configId", web.MoreSeriesList)
	r.GET("/series", web.Series)
	r.GET("/series/:media/:topic/:sortType", web.Series)
	r.GET("/series/:media/:topic/:sortType/page/:page", web.Series)
	r.GET("/topic", web.Topic)
	r.GET("/topic/page/:page", web.Topic)
	r.GET("/topic/sort/:sortType", web.Topic)
	r.GET("/topic/sort/:sortType/page/:page", web.Topic)
	r.GET("/topic-detail/:slug/sort/:sortType/page/:page", web.TopicDetail)
	r.GET("/topic-detail/:slug/sort/:sortType", web.TopicDetail)
	r.GET("/topic-detail/:slug/page/:page", web.TopicDetail)
	r.GET("/topic-detail/:slug", web.TopicDetail)
	r.GET("/rank", web.Rank)
	r.GET("/rank/page/:page", web.Rank)
	r.GET("/rank/:sortOrder", web.Rank)
	r.GET("/rank/:sortOrder/page/:page", web.Rank)
	r.GET("/tags/:slug/sort/:sortType/page/:page", web.Tags)
	r.GET("/tags/:slug/sort/:sortType", web.Tags)
	r.GET("/tags/:slug/page/:page", web.Tags)
	r.GET("/tags/:slug", web.Tags)
	r.GET("/recently-added", web.RecentlyAdded)
	r.GET("/recently-added/page/:page", web.RecentlyAdded)
	r.GET("/popular-recommend", web.PopularRecommend)
	r.GET("/popular-recommend/page/:page", web.PopularRecommend)
	r.GET("/popular-recommend/:rankType", web.PopularRecommend)
	r.GET("/popular-recommend/:rankType/page/:page", web.PopularRecommend)
	r.GET("/play/:slug", web.Play)
	r.GET("/play/:slug/:ep", web.Play)
	r.GET("/play/:slug/recommendations/page/:guessPage", web.Play)
	r.GET("/play/:slug/:ep/recommendations/page/:guessPage", web.Play)
	r.GET("/series-play/:slug", web.SeriesPlay)
	r.GET("/series-play/:slug/recommendations/page/:guessPage", web.SeriesPlay)
	r.GET("/feedback", web.Feedback)

	// 意见反馈（含截图上传）
	r.POST("/api/upload/image", web.UploadImage)
	r.POST("/api/feedback/add", web.FeedbackAdd)

	// 播放页 BFF
	r.GET("/api/playlet/guess-like/list", web.GuessLikeList)
	r.GET("/api/comment/list", web.CommentList)
	r.GET("/api/web/search/suggest", web.SearchSuggest)

	// 搜索引擎抓取、发现与站点所有权验证。
	r.GET("/robots.txt", web.RobotsTXT)
	r.GET("/llms.txt", web.LLMSTXT)
	if key := seoser.VerifyFromConfig().IndexNowKey; key != "" {
		r.GET("/"+key+".txt", web.SEOVerifyFile)
	}

	r.NoRoute(web.NotFound)
}