// bilibili B站执行器（无浏览器投稿 + API 扫码登录）。
// 协议依据：ForgQi/biliup（MIT）bili_webup.py 的 upos/bda2 上传链路。
package bilibili

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"time"

	"everypublish/agentcore/internal/exec"
	"everypublish/agentcore/internal/vault"
	"everypublish/shared/proto"
)

// Executor B站投稿执行器
type Executor struct {
	Vault        *vault.Vault
	HTTP         *http.Client
	MemberBase   string // 投稿 API 基址（测试可替换）
	PassportBase string // 登录 API 基址（测试可替换）
	UpOSScheme   string // upos 上传协议（默认 https，测试 http）
	PollTimeout  time.Duration // 扫码轮询总时长（默认 3 分钟）
}

// New 构造执行器
func New(v *vault.Vault) *Executor {
	return &Executor{
		Vault:        v,
		HTTP:         &http.Client{Timeout: 30 * time.Second},
		MemberBase:   "https://member.bilibili.com",
		PassportBase: "https://passport.bilibili.com",
		UpOSScheme:   "https",
		PollTimeout:  3 * time.Minute,
	}
}

// Platform 平台标识
func (e *Executor) Platform() string { return "bilibili" }

// credentials 凭据（保险库 JSON）
type credentials struct {
	Cookies string `json:"cookies"`
}

// Execute 发布：下载素材 → upos 上传 → 投稿 → 返回作品链接
func (e *Executor) Execute(ctx context.Context, task exec.Task) exec.Result {
	fail := func(err string) exec.Result {
		return exec.Result{TaskID: task.TaskID, Status: "failed", Error: err}
	}
	creds, err := e.creds(task.AccountID)
	if err != nil {
		return fail("B站账号未登录（本地无凭据），请先在客户端完成扫码绑定")
	}
	if len(task.MaterialURLs) == 0 {
		return fail("任务缺少素材")
	}
	videoPath, cleanup, err := downloadFile(ctx, e.HTTP, task.MaterialURLs[0])
	if err != nil {
		return fail("素材下载失败: " + err.Error())
	}
	defer cleanup()
	part, err := e.uploadVideo(ctx, creds.Cookies, videoPath)
	if err != nil {
		return fail("视频上传失败: " + err.Error())
	}
	bvid, err := e.submit(ctx, creds.Cookies, task, part)
	if err != nil {
		return fail("投稿提交失败: " + err.Error())
	}
	return exec.Result{
		TaskID:       task.TaskID,
		Status:       "success",
		PublishedURL: "https://www.bilibili.com/video/" + bvid,
	}
}

func (e *Executor) creds(accountID string) (*credentials, error) {
	raw, err := e.Vault.Load(accountID)
	if err != nil {
		return nil, err
	}
	var c credentials
	if err = json.Unmarshal(raw, &c); err != nil {
		return nil, err
	}
	if c.Cookies == "" {
		return nil, fmt.Errorf("empty cookies")
	}
	return &c, nil
}

// uploadVideo 上传视频（upos/bda2 分片），返回投稿所需的 part 信息
func (e *Executor) uploadVideo(ctx context.Context, cookies, filePath string) (map[string]interface{}, error) {
	stat, err := os.Stat(filePath)
	if err != nil {
		return nil, err
	}
	name := filepath.Base(filePath)
	total := stat.Size()

	// 1) preupload 获取上传地址
	q := url.Values{}
	q.Set("r", "upos")
	q.Set("profile", "ugcupos/bup")
	q.Set("ssl", "0")
	q.Set("version", "2.8.12")
	q.Set("build", "2081200")
	q.Set("name", name)
	q.Set("size", strconv.FormatInt(total, 10))
	preURL := e.MemberBase + "/preupload?upcdn=bda2&probe_version=20221109&" + q.Encode()
	var pre struct {
		OK        int    `json:"OK"`
		Endpoint  string `json:"endpoint"`
		Auth      string `json:"auth"`
		BizID     int    `json:"biz_id"`
		UposURI   string `json:"upos_uri"`
		ChunkSize int    `json:"chunk_size"`
	}
	if err = e.getJSON(ctx, preURL, cookies, &pre); err != nil {
		return nil, err
	}
	if pre.OK != 1 || pre.UposURI == "" {
		return nil, fmt.Errorf("preupload 返回异常")
	}
	upURL := e.UpOSScheme + ":" + pre.Endpoint + "/" + strings.TrimPrefix(pre.UposURI, "upos://")
	authH := map[string]string{"X-Upos-Auth": pre.Auth}

	// 2) 申请 upload_id
	var up struct {
		UploadID string `json:"upload_id"`
	}
	if err = e.postJSON(ctx, upURL+"?uploads&output=json", cookies, authH, nil, &up); err != nil {
		return nil, fmt.Errorf("申请 upload_id 失败: %w", err)
	}

	// 3) 分片上传
	chunkSize := pre.ChunkSize
	if chunkSize <= 0 {
		chunkSize = 7 * 1024 * 1024
	}
	chunks := int((total + int64(chunkSize) - 1) / int64(chunkSize))
	f, err := os.Open(filePath)
	if err != nil {
		return nil, err
	}
	defer f.Close()
	parts := make([]map[string]interface{}, 0, chunks)
	buf := make([]byte, chunkSize)
	for i := 0; i < chunks; i++ {
		n, rerr := io.ReadFull(f, buf)
		if rerr != nil && rerr != io.ErrUnexpectedEOF && rerr != io.EOF {
			return nil, rerr
		}
		start := i * chunkSize
		end := start + n
		pq := url.Values{}
		pq.Set("uploadId", up.UploadID)
		pq.Set("partNumber", strconv.Itoa(i+1))
		pq.Set("chunk", strconv.Itoa(i))
		pq.Set("chunks", strconv.Itoa(chunks))
		pq.Set("size", strconv.Itoa(n))
		pq.Set("start", strconv.Itoa(start))
		pq.Set("end", strconv.Itoa(end))
		pq.Set("total", strconv.FormatInt(total, 10))
		if err = e.putBody(ctx, upURL+"?"+pq.Encode(), cookies, authH, buf[:n]); err != nil {
			return nil, fmt.Errorf("分片 %d 上传失败: %w", i+1, err)
		}
		parts = append(parts, map[string]interface{}{"partNumber": i + 1, "eTag": "etag"})
	}

	// 4) 合并分片
	mq := url.Values{}
	mq.Set("name", name)
	mq.Set("uploadId", up.UploadID)
	mq.Set("biz_id", strconv.Itoa(pre.BizID))
	mq.Set("output", "json")
	mq.Set("profile", "ugcupos/bup")
	var merged struct {
		OK int `json:"OK"`
	}
	if err = e.postJSON(ctx, upURL+"?"+mq.Encode(), cookies, authH, map[string]interface{}{"parts": parts}, &merged); err != nil {
		return nil, err
	}
	if merged.OK != 1 {
		return nil, fmt.Errorf("分片合并返回异常")
	}
	return map[string]interface{}{
		"title":    strings.TrimSuffix(name, filepath.Ext(name)),
		"filename": strings.TrimSuffix(filepath.Base(pre.UposURI), filepath.Ext(filepath.Base(pre.UposURI))),
		"desc":     "",
	}, nil
}

// submit 投稿（x/vu/web/add）
func (e *Executor) submit(ctx context.Context, cookies string, task exec.Task, part map[string]interface{}) (string, error) {
	csrf := cookieValue(cookies, "bili_jct")
	// 风控预热（失败不影响）
	_, _ = e.get(ctx, e.MemberBase+"/x/geetest/pre/add", cookies)
	tag := strings.Join(task.Tags, ",")
	if tag == "" {
		tag = "日常"
	}
	body := map[string]interface{}{
		"title":    truncateRunes(task.Title, 80),
		"desc":     task.Content,
		"desc_v2":  []map[string]interface{}{{"raw_text": task.Content, "type": 1, "biz_id": ""}},
		"copyright": 1,
		"source":   "",
		"tid":      174,
		"tag":      tag,
		"dynamic":  "",
		"videos":   []map[string]interface{}{part},
	}
	var ret struct {
		Code    int    `json:"code"`
		Message string `json:"message"`
		Data    struct {
			Bvid string `json:"bvid"`
		} `json:"data"`
	}
	if err := e.postJSON(ctx, e.MemberBase+"/x/vu/web/add?csrf="+csrf, cookies, nil, body, &ret); err != nil {
		return "", err
	}
	if ret.Code != 0 {
		return "", fmt.Errorf("code=%d %s", ret.Code, ret.Message)
	}
	return ret.Data.Bvid, nil
}

// SolveChallenge B站扫码登录：生成二维码 → onQR 展示 → 轮询 → 保存 cookie
func (e *Executor) SolveChallenge(ctx context.Context, ch proto.Challenge, onQR func(qrToken, qrURL string)) (bool, string) {
	key, qrURL, err := e.generateQR(ctx)
	if err != nil {
		return false, ""
	}
	if onQR != nil {
		onQR(key, qrURL)
	}
	deadline := time.Now().Add(e.PollTimeout)
	for time.Now().Before(deadline) {
		select {
		case <-ctx.Done():
			return false, ""
		default:
		}
		code, cookieURL, perr := e.pollQR(ctx, key)
		if perr != nil {
			return false, ""
		}
		switch code {
		case 0:
			cookies := cookiesFromCrossDomainURL(cookieURL)
			if cookies == "" {
				return false, ""
			}
			_ = e.Vault.Save(ch.AccountID, []byte(`{"cookies":"`+jsonEscape(cookies)+`"}`))
			return true, "confirmed"
		case 86090:
		case 86101:
		default:
			return false, ""
		}
		time.Sleep(2 * time.Second)
	}
	return false, ""
}

// generateQR 生成登录二维码
func (e *Executor) generateQR(ctx context.Context) (key, qrURL string, err error) {
	var ret struct {
		Code int `json:"code"`
		Data struct {
			URL       string `json:"url"`
			QrcodeKey string `json:"qrcode_key"`
		} `json:"data"`
	}
	if err = e.getJSON(ctx, e.PassportBase+"/x/passport-login/web/qrcode/generate", "", &ret); err != nil {
		return "", "", err
	}
	if ret.Code != 0 || ret.Data.QrcodeKey == "" {
		return "", "", fmt.Errorf("生成二维码失败 code=%d", ret.Code)
	}
	return ret.Data.QrcodeKey, ret.Data.URL, nil
}

// pollQR 轮询扫码状态：86101 未扫 / 86090 已扫待确认 / 0 成功（返回跨域 cookie URL）
func (e *Executor) pollQR(ctx context.Context, key string) (int, string, error) {
	var ret struct {
		Code int `json:"code"`
		Data struct {
			URL string `json:"url"`
		} `json:"data"`
	}
	if err := e.getJSON(ctx, e.PassportBase+"/x/passport-login/web/qrcode/poll?qrcode_key="+key, "", &ret); err != nil {
		return 0, "", err
	}
	return ret.Code, ret.Data.URL, nil
}

// ---- HTTP 辅助 ----

func (e *Executor) get(ctx context.Context, rawURL, cookies string) ([]byte, error) {
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, rawURL, nil)
	if err != nil {
		return nil, err
	}
	if cookies != "" {
		req.Header.Set("Cookie", cookies)
	}
	req.Header.Set("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 Chrome/120 Safari/537.36")
	req.Header.Set("Referer", "https://member.bilibili.com")
	resp, err := e.HTTP.Do(req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	return io.ReadAll(resp.Body)
}

func (e *Executor) getJSON(ctx context.Context, rawURL, cookies string, out interface{}) error {
	raw, err := e.get(ctx, rawURL, cookies)
	if err != nil {
		return err
	}
	return json.Unmarshal(raw, out)
}

func (e *Executor) postJSON(ctx context.Context, rawURL, cookies string, extraH map[string]string, body interface{}, out interface{}) error {
	var buf bytes.Buffer
	if body != nil {
		raw, _ := json.Marshal(body)
		buf.Write(raw)
	}
	req, err := http.NewRequestWithContext(ctx, http.MethodPost, rawURL, &buf)
	if err != nil {
		return err
	}
	if cookies != "" {
		req.Header.Set("Cookie", cookies)
	}
	for k, v := range extraH {
		req.Header.Set(k, v)
	}
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 Chrome/120 Safari/537.36")
	req.Header.Set("Referer", "https://member.bilibili.com")
	resp, err := e.HTTP.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	raw, _ := io.ReadAll(resp.Body)
	if resp.StatusCode >= 400 {
		return fmt.Errorf("http %d", resp.StatusCode)
	}
	if out == nil {
		return nil
	}
	return json.Unmarshal(raw, out)
}

func (e *Executor) putBody(ctx context.Context, rawURL, cookies string, extraH map[string]string, data []byte) error {
	req, err := http.NewRequestWithContext(ctx, http.MethodPut, rawURL, bytes.NewReader(data))
	if err != nil {
		return err
	}
	if cookies != "" {
		req.Header.Set("Cookie", cookies)
	}
	for k, v := range extraH {
		req.Header.Set(k, v)
	}
	resp, err := e.HTTP.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	if resp.StatusCode >= 400 {
		return fmt.Errorf("http %d", resp.StatusCode)
	}
	return nil
}

// downloadFile 下载素材到临时文件
func downloadFile(ctx context.Context, client *http.Client, rawURL string) (string, func(), error) {
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, rawURL, nil)
	if err != nil {
		return "", nil, err
	}
	resp, err := client.Do(req)
	if err != nil {
		return "", nil, err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return "", nil, fmt.Errorf("下载 http %d", resp.StatusCode)
	}
	tmp, err := os.CreateTemp("", "ep-material-*")
	if err != nil {
		return "", nil, err
	}
	_, err = io.Copy(tmp, resp.Body)
	tmp.Close()
	if err != nil {
		os.Remove(tmp.Name())
		return "", nil, err
	}
	return tmp.Name(), func() { _ = os.Remove(tmp.Name()) }, nil
}

// cookieValue 从 cookie 串取值
func cookieValue(cookies, key string) string {
	for _, part := range strings.Split(cookies, ";") {
		part = strings.TrimSpace(part)
		if i := strings.Index(part, "="); i > 0 && part[:i] == key {
			return part[i+1:]
		}
	}
	return ""
}

// cookiesFromCrossDomainURL 从跨域跳转 URL 提取登录 cookie
func cookiesFromCrossDomainURL(rawURL string) string {
	u, err := url.Parse(rawURL)
	if err != nil {
		return ""
	}
	q := u.Query()
	sess := q.Get("SESSDATA")
	jct := q.Get("bili_jct")
	dede := q.Get("DedeUserID")
	if sess == "" {
		return ""
	}
	return "SESSDATA=" + sess + "; bili_jct=" + jct + "; DedeUserID=" + dede
}

func truncateRunes(s string, max int) string {
	r := []rune(s)
	if len(r) <= max {
		return s
	}
	return string(r[:max])
}

func jsonEscape(s string) string {
	raw, _ := json.Marshal(s)
	return string(raw[1 : len(raw)-1])
}