package playletser

import (
	"fmt"
	"net/url"
	"strconv"
	"strings"
	"videoweb/app/service/authser"
	"videoweb/app/service/upstream"
	"videoweb/pub/common/log"

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

const (
	detailPath          = "/api/app/playlet/detail"
	defaultEpisodeRange = 30
)

// EpisodeRange 剧集分段（仅 UI 分页展示，非接口字段映射）。
type EpisodeRange struct {
	Start int
	End   int
	Label string
}

// FetchDetail 根据短剧 ID 查询详情。
func FetchDetail(c *gin.Context, id int64) (*PlayletInfoResp, error) {
	if id <= 0 {
		return nil, fmt.Errorf("playlet detail invalid id")
	}
	return fetchDetail(c, "id", strconv.FormatInt(id, 10))
}

// FetchDetailByKey 优先按 slug 查询；纯数字路由段按 ID 查询。
func FetchDetailByKey(c *gin.Context, key string) (*PlayletInfoResp, error) {
	key = strings.TrimSpace(key)
	if key == "" {
		return nil, fmt.Errorf("playlet detail missing route key")
	}
	if id := ParseDetailID(key); id > 0 {
		return FetchDetail(c, id)
	}
	return fetchDetail(c, "slug", key)
}

func fetchDetail(c *gin.Context, queryKey, value string) (*PlayletInfoResp, error) {
	authser.EnsureGuestOnEnter(c)
	env, err := fetchDetailOnce(c, queryKey, value)
	if err != nil {
		return nil, err
	}
	if env.Code != 200 && authser.IsSessionExpiredCode(env.Code) {
		if authser.RecoverContentSession(c, env.Code) {
			env, err = fetchDetailOnce(c, queryKey, value)
			if err != nil {
				return nil, err
			}
		}
	}
	if env.Code != 200 {
		return nil, fmt.Errorf("playlet detail code=%d msg=%s tip=%s", env.Code, env.Msg, env.Tip)
	}
	env.Data.SeoInfo.Normalize()
	return &env.Data, nil
}

func fetchDetailOnce(c *gin.Context, queryKey, value string) (*APIEnvelope[PlayletInfoResp], error) {
	params := url.Values{}
	params.Set(queryKey, value)
	var env APIEnvelope[PlayletInfoResp]
	if err := upstream.GetJSON(c, detailPath+"?"+params.Encode(), &env); err != nil {
		return nil, err
	}
	return &env, nil
}

// FetchDetailOrNilByKey 失败或无效时返回 nil。
func FetchDetailOrNilByKey(c *gin.Context, key string) *PlayletInfoResp {
	data, err := FetchDetailByKey(c, key)
	if err != nil {
		log.Error("fetch playlet detail by route key failed", log.E(err))
		return nil
	}
	if data == nil || data.ID <= 0 {
		return nil
	}
	return data
}

// ParseDetailID 解析纯数字路由段。
func ParseDetailID(raw string) int64 {
	id, err := strconv.ParseInt(strings.TrimSpace(raw), 10, 64)
	if err != nil || id <= 0 {
		return 0
	}
	return id
}

// BuildEpisodeRanges 按集数分段（默认每段 30 集）。
func BuildEpisodeRanges(chapters []PlayletChapterData, totalEpisode, size int) []EpisodeRange {
	if size <= 0 {
		size = defaultEpisodeRange
	}
	maxEp := 0
	for _, ch := range chapters {
		if ch.CurrentEpisode > maxEp {
			maxEp = ch.CurrentEpisode
		}
	}
	if totalEpisode > maxEp {
		maxEp = totalEpisode
	}
	if maxEp <= 0 {
		maxEp = len(chapters)
	}
	if maxEp <= 0 {
		return nil
	}
	out := make([]EpisodeRange, 0, (maxEp+size-1)/size)
	for start := 1; start <= maxEp; start += size {
		end := start + size - 1
		if end > maxEp {
			end = maxEp
		}
		out = append(out, EpisodeRange{
			Start: start,
			End:   end,
			Label: fmt.Sprintf("%d–%d", start, end),
		})
	}
	return out
}