package auth

import (
	"bytes"
	"crypto/sha256"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"math/rand"
	"net/http"
	"net/url"
	"strings"
	"time"

	"codex-pool/internal/client"
)

// 常量 CodexClientID, CodexRedirectURI, CodexScope 已在 s2a.go 中定义

// CodexAPIAuth 纯 API 授权 (无浏览器)
type CodexAPIAuth struct {
	client        *client.TLSClient
	email         string
	password      string
	workspaceID   string
	deviceID      string
	sid           string
	sentinelToken string
	solvedPow     string
	userAgent     string
	logger        *AuthLogger
}

// NewCodexAPIAuth 创建 CodexAuth 实例
func NewCodexAPIAuth(email, password, workspaceID, proxy string, logger *AuthLogger) (*CodexAPIAuth, error) {
	tlsClient, err := client.New(proxy)
	if err != nil {
		return nil, fmt.Errorf("创建 TLS 客户端失败: %v", err)
	}

	return &CodexAPIAuth{
		client:      tlsClient,
		email:       email,
		password:    password,
		workspaceID: workspaceID,
		deviceID:    generateUUID(),
		sid:         generateUUID(),
		userAgent:   "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36",
		logger:      logger,
	}, nil
}

// generateUUID 生成 UUID v4
func generateUUID() string {
	b := make([]byte, 16)
	rand.Read(b)
	b[6] = (b[6] & 0x0f) | 0x40
	b[8] = (b[8] & 0x3f) | 0x80
	return fmt.Sprintf("%x-%x-%x-%x-%x", b[0:4], b[4:6], b[6:8], b[8:10], b[10:])
}

// generateCodeVerifier 生成 PKCE code_verifier
func generateCodeVerifier() string {
	b := make([]byte, 64)
	rand.Read(b)
	return base64.RawURLEncoding.EncodeToString(b)
}

// generateCodeChallenge 生成 PKCE code_challenge (S256)
func generateCodeChallenge(verifier string) string {
	hash := sha256.Sum256([]byte(verifier))
	return base64.RawURLEncoding.EncodeToString(hash[:])
}

// generateState 生成 state
func generateState() string {
	b := make([]byte, 16)
	rand.Read(b)
	return base64.RawURLEncoding.EncodeToString(b)
}

// fnv1a32 FNV-1a 32-bit hash
func fnv1a32(data []byte) uint32 {
	h := uint32(2166136261)
	for _, b := range data {
		h ^= uint32(b)
		h *= 16777619
	}
	h ^= (h >> 16)
	h *= 2246822507
	h ^= (h >> 13)
	h *= 3266489909
	h ^= (h >> 16)
	return h
}

// getParseTime 生成 JS Date().toString() 格式的时间字符串
func getParseTime() string {
	now := time.Now()
	return now.Format("Mon Jan 02 2006 15:04:05") + " GMT+0800 (中国标准时间)"
}

// getConfig 生成 PoW 配置数组
func (c *CodexAPIAuth) getConfig() []interface{} {
	return []interface{}{
		2500 + rand.Intn(1000),
		getParseTime(),
		4294967296,
		0,
		c.userAgent,
		"chrome-extension://pgojnojmmhpofjgdmaebadhbocahppod/assets/aW5qZWN0X2hhc2g/aW5qZ",
		nil,
		"zh-CN",
		"zh-CN",
		0,
		"canShare−function canShare() { [native code] }",
		fmt.Sprintf("_reactListening%d", 1000000+rand.Intn(9000000)),
		"onhashchange",
		float64(time.Now().UnixNano()/1e6) / 1000.0,
		c.sid,
		"",
		24,
		time.Now().UnixMilli() - int64(10000+rand.Intn(40000)),
	}
}

// solvePow 解决 PoW 挑战
func (c *CodexAPIAuth) solvePow(seed, difficulty string, cfg []interface{}, maxIterations int) string {
	seedBytes := []byte(seed)

	for i := 0; i < maxIterations; i++ {
		cfg[3] = i
		cfg[9] = 0

		jsonStr, _ := json.Marshal(cfg)
		encoded := base64.StdEncoding.EncodeToString(jsonStr)

		h := fnv1a32(append(seedBytes, []byte(encoded)...))
		hexHash := fmt.Sprintf("%08x", h)

		if hexHash[:len(difficulty)] <= difficulty {
			return encoded + "~S"
		}
	}

	return ""
}

// getRequirementsToken 生成初始 token
func (c *CodexAPIAuth) getRequirementsToken() string {
	cfg := c.getConfig()
	cfg[3] = 0
	cfg[9] = 0
	jsonStr, _ := json.Marshal(cfg)
	encoded := base64.StdEncoding.EncodeToString(jsonStr)
	return "gAAAAAC" + encoded + "~S"
}

// callSentinelReq 调用 Sentinel 获取 token
func (c *CodexAPIAuth) callSentinelReq(flow string) error {
	initToken := c.getRequirementsToken()
	payload := map[string]interface{}{
		"p":    initToken,
		"id":   c.deviceID,
		"flow": flow,
	}

	body, _ := json.Marshal(payload)
	req, _ := http.NewRequest("POST", "https://sentinel.openai.com/backend-api/sentinel/req", bytes.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Accept", "application/json")

	resp, err := c.client.Do(req)
	if err != nil {
		return fmt.Errorf("sentinel 请求失败: %v", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != 200 {
		return fmt.Errorf("sentinel 状态码: %d", resp.StatusCode)
	}

	respBody, _ := client.ReadBody(resp)
	var result struct {
		Token       string `json:"token"`
		ProofOfWork struct {
			Required   bool   `json:"required"`
			Seed       string `json:"seed"`
			Difficulty string `json:"difficulty"`
		} `json:"proofofwork"`
	}

	if err := json.Unmarshal(respBody, &result); err != nil {
		return fmt.Errorf("解析 sentinel 响应失败: %v", err)
	}

	c.sentinelToken = result.Token

	if result.ProofOfWork.Required {
		cfg := c.getConfig()
		solved := c.solvePow(result.ProofOfWork.Seed, result.ProofOfWork.Difficulty, cfg, 5000000)
		if solved == "" {
			return fmt.Errorf("PoW 解决失败")
		}
		c.solvedPow = "gAAAAAB" + solved
	} else {
		c.solvedPow = initToken
	}

	return nil
}

// getSentinelHeader 构建 sentinel header
func (c *CodexAPIAuth) getSentinelHeader(flow string) string {
	obj := map[string]interface{}{
		"p":    c.solvedPow,
		"id":   c.deviceID,
		"flow": flow,
	}
	if c.sentinelToken != "" {
		obj["c"] = c.sentinelToken
	}
	header, _ := json.Marshal(obj)
	return string(header)
}

// logStep 记录日志
func (c *CodexAPIAuth) logStep(step AuthStep, format string, args ...interface{}) {
	if c.logger != nil {
		c.logger.LogStep(step, format, args...)
	}
}

// logError 记录错误
func (c *CodexAPIAuth) logError(step AuthStep, format string, args ...interface{}) {
	if c.logger != nil {
		c.logger.LogError(step, format, args...)
	}
}

// ObtainAuthorizationCode 获取授权码
func (c *CodexAPIAuth) ObtainAuthorizationCode() (string, error) {
	c.logStep(StepNavigate, "开始 Codex API 授权流程...")

	// 1. 生成 PKCE 参数
	codeVerifier := generateCodeVerifier()
	codeChallenge := generateCodeChallenge(codeVerifier)
	state := generateState()

	// 2. 构建授权 URL
	params := url.Values{
		"client_id":                  {CodexClientID},
		"scope":                      {CodexScope},
		"response_type":              {"code"},
		"redirect_uri":               {CodexRedirectURI},
		"code_challenge":             {codeChallenge},
		"code_challenge_method":      {"S256"},
		"state":                      {state},
		"id_token_add_organizations": {"true"},
		"codex_cli_simplified_flow":  {"true"},
		"originator":                 {"codex_cli_rs"},
	}

	authURL := "https://auth.openai.com/oauth/authorize?" + params.Encode()

	// 3. 访问授权页面
	c.logStep(StepNavigate, "访问授权页面...")
	req, _ := http.NewRequest("GET", authURL, nil)
	req.Header.Set("Referer", "https://auth.openai.com/log-in")
	resp, err := c.client.Do(req)
	if err != nil {
		c.logError(StepNavigate, "访问授权页失败: %v", err)
		return "", fmt.Errorf("访问授权页失败: %v", err)
	}
	defer resp.Body.Close()
	client.ReadBody(resp) // 消耗响应体
	referer := resp.Request.URL.String()

	// 4. 提交邮箱
	c.logStep(StepInputEmail, "提交邮箱: %s", c.email)
	if err := c.callSentinelReq("login_web_init"); err != nil {
		c.logError(StepInputEmail, "Sentinel 请求失败: %v", err)
		return "", err
	}

	emailPayload := map[string]interface{}{
		"username": map[string]string{
			"kind":  "email",
			"value": c.email,
		},
	}
	emailBody, _ := json.Marshal(emailPayload)

	req, _ = http.NewRequest("POST", "https://auth.openai.com/api/accounts/authorize/continue", bytes.NewReader(emailBody))
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Origin", "https://auth.openai.com")
	req.Header.Set("Referer", referer)
	req.Header.Set("OpenAI-Sentinel-Token", c.getSentinelHeader("authorize_continue"))

	resp, err = c.client.Do(req)
	if err != nil {
		c.logError(StepInputEmail, "提交邮箱失败: %v", err)
		return "", fmt.Errorf("提交邮箱失败: %v", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != 200 {
		body, _ := client.ReadBody(resp)
		c.logError(StepInputEmail, "提交邮箱失败: %d - %s", resp.StatusCode, string(body))
		return "", fmt.Errorf("提交邮箱失败: %d", resp.StatusCode)
	}

	// 解析响应，检查是否需要密码
	emailResp, _ := client.ReadBody(resp)
	var emailResult map[string]interface{}
	json.Unmarshal(emailResp, &emailResult)

	// 5. 验证密码
	c.logStep(StepInputPassword, "验证密码...")
	if err := c.callSentinelReq("authorize_continue__auto"); err != nil {
		c.logError(StepInputPassword, "Sentinel 请求失败: %v", err)
		return "", err
	}

	pwdPayload := map[string]string{
		"username": c.email,
		"password": c.password,
	}
	pwdBody, _ := json.Marshal(pwdPayload)

	req, _ = http.NewRequest("POST", "https://auth.openai.com/api/accounts/password/verify", bytes.NewReader(pwdBody))
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Origin", "https://auth.openai.com")
	req.Header.Set("Referer", referer)
	req.Header.Set("OpenAI-Sentinel-Token", c.getSentinelHeader("password_verify"))

	resp, err = c.client.Do(req)
	if err != nil {
		c.logError(StepInputPassword, "验证密码失败: %v", err)
		return "", fmt.Errorf("验证密码失败: %v", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != 200 {
		body, _ := client.ReadBody(resp)
		c.logError(StepInputPassword, "密码验证失败: %d - %s", resp.StatusCode, string(body))
		return "", fmt.Errorf("密码验证失败: %d", resp.StatusCode)
	}

	// 6. 选择工作区
	c.logStep(StepSelectWorkspace, "选择工作区: %s", c.workspaceID)
	if err := c.callSentinelReq("password_verify__auto"); err != nil {
		c.logError(StepSelectWorkspace, "Sentinel 请求失败: %v", err)
		return "", err
	}

	wsPayload := map[string]string{
		"workspace_id": c.workspaceID,
	}
	wsBody, _ := json.Marshal(wsPayload)

	req, _ = http.NewRequest("POST", "https://auth.openai.com/api/accounts/workspace/select", bytes.NewReader(wsBody))
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Origin", "https://auth.openai.com")
	req.Header.Set("Referer", referer)

	resp, err = c.client.Do(req)
	if err != nil {
		c.logError(StepSelectWorkspace, "选择工作区失败: %v", err)
		return "", fmt.Errorf("选择工作区失败: %v", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != 200 {
		body, _ := client.ReadBody(resp)
		c.logError(StepSelectWorkspace, "选择工作区失败: %d - %s", resp.StatusCode, string(body))
		return "", fmt.Errorf("选择工作区失败: %d", resp.StatusCode)
	}

	// 解析 continue_url
	wsResp, _ := client.ReadBody(resp)
	c.logStep(StepSelectWorkspace, "工作区响应: %s", string(wsResp))

	var wsResult struct {
		ContinueURL string `json:"continue_url"`
		Page        struct {
			Type string `json:"type"`
		} `json:"page"`
		Error   string `json:"error"`
		Message string `json:"message"`
	}
	if err := json.Unmarshal(wsResp, &wsResult); err != nil {
		c.logError(StepSelectWorkspace, "解析响应失败: %v, 原始: %s", err, string(wsResp))
		return "", fmt.Errorf("解析响应失败: %v", err)
	}

	if wsResult.ContinueURL == "" {
		c.logError(StepSelectWorkspace, "未获取到 continue_url, page=%s, error=%s, msg=%s",
			wsResult.Page.Type, wsResult.Error, wsResult.Message)
		return "", fmt.Errorf("未获取到 continue_url")
	}

	// 7. 跟随重定向获取授权码
	c.logStep(StepWaitCallback, "跟随重定向...")
	continueURL := wsResult.ContinueURL

	for i := 0; i < 10; i++ {
		req, _ = http.NewRequest("GET", continueURL, nil)
		resp, err = c.client.Do(req)
		if err != nil {
			break
		}

		location := resp.Header.Get("Location")
		resp.Body.Close()

		if resp.StatusCode >= 301 && resp.StatusCode <= 308 {
			if strings.Contains(location, "localhost:1455") {
				// 提取授权码
				code := ExtractCodeFromCallbackURL(location)
				if code != "" {
					c.logStep(StepComplete, "授权成功，获取到授权码")
					return code, nil
				}
			}
			continueURL = location
		} else {
			break
		}
	}

	c.logError(StepWaitCallback, "未能获取授权码")
	return "", fmt.Errorf("未能获取授权码")
}

// ExchangeCodeForTokens 用授权码换取 tokens
func (c *CodexAPIAuth) ExchangeCodeForTokens(code, codeVerifier string) (*CodexTokens, error) {
	payload := map[string]string{
		"grant_type":    "authorization_code",
		"client_id":     CodexClientID,
		"code_verifier": codeVerifier,
		"code":          code,
		"redirect_uri":  CodexRedirectURI,
	}

	body, _ := json.Marshal(payload)
	req, _ := http.NewRequest("POST", "https://auth.openai.com/oauth/token", bytes.NewReader(body))
	req.Header.Set("Content-Type", "application/json")

	resp, err := c.client.Do(req)
	if err != nil {
		return nil, fmt.Errorf("token 交换失败: %v", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != 200 {
		respBody, _ := client.ReadBody(resp)
		return nil, fmt.Errorf("token 交换失败: %d - %s", resp.StatusCode, string(respBody))
	}

	respBody, _ := client.ReadBody(resp)
	var tokens CodexTokens
	if err := json.Unmarshal(respBody, &tokens); err != nil {
		return nil, fmt.Errorf("解析 token 失败: %v", err)
	}

	if tokens.ExpiresIn > 0 {
		expiredAt := time.Now().Add(time.Duration(tokens.ExpiresIn) * time.Second)
		tokens.ExpiredAt = expiredAt.Format(time.RFC3339)
	}

	return &tokens, nil
}

// CodexTokens 结构体已在 s2a.go 中定义
// CompleteWithCodexAPI 使用纯 API 方式完成授权
func CompleteWithCodexAPI(email, password, workspaceID, proxy string, logger *AuthLogger) (string, error) {
	if logger != nil {
		logger.LogStep(StepBrowserStart, "使用 CodexAuth API 模式...")
	}

	auth, err := NewCodexAPIAuth(email, password, workspaceID, proxy, logger)
	if err != nil {
		if logger != nil {
			logger.LogError(StepBrowserStart, "创建 CodexAuth 失败: %v", err)
		}
		return "", err
	}

	code, err := auth.ObtainAuthorizationCode()
	if err != nil {
		return "", err
	}

	return code, nil
}