package admin

import (
	"strconv"
	"strings"

	"github.com/Wei-Shaw/sub2api/internal/handler/dto"
	"github.com/Wei-Shaw/sub2api/internal/pkg/openai"
	"github.com/Wei-Shaw/sub2api/internal/pkg/response"
	"github.com/Wei-Shaw/sub2api/internal/service"

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

// OpenAIOAuthHandler handles OpenAI OAuth-related operations
type OpenAIOAuthHandler struct {
	openaiOAuthService *service.OpenAIOAuthService
	adminService       service.AdminService
}

func oauthPlatformFromPath(c *gin.Context) string {
	if strings.Contains(c.FullPath(), "/admin/sora/") {
		return service.PlatformSora
	}
	return service.PlatformOpenAI
}

// NewOpenAIOAuthHandler creates a new OpenAI OAuth handler
func NewOpenAIOAuthHandler(openaiOAuthService *service.OpenAIOAuthService, adminService service.AdminService) *OpenAIOAuthHandler {
	return &OpenAIOAuthHandler{
		openaiOAuthService: openaiOAuthService,
		adminService:       adminService,
	}
}

// OpenAIGenerateAuthURLRequest represents the request for generating OpenAI auth URL
type OpenAIGenerateAuthURLRequest struct {
	ProxyID     *int64 `json:"proxy_id"`
	RedirectURI string `json:"redirect_uri"`
}

// GenerateAuthURL generates OpenAI OAuth authorization URL
// POST /api/v1/admin/openai/generate-auth-url
func (h *OpenAIOAuthHandler) GenerateAuthURL(c *gin.Context) {
	var req OpenAIGenerateAuthURLRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		// Allow empty body
		req = OpenAIGenerateAuthURLRequest{}
	}

	result, err := h.openaiOAuthService.GenerateAuthURL(
		c.Request.Context(),
		req.ProxyID,
		req.RedirectURI,
		oauthPlatformFromPath(c),
	)
	if err != nil {
		response.ErrorFrom(c, err)
		return
	}

	response.Success(c, result)
}

// OpenAIExchangeCodeRequest represents the request for exchanging OpenAI auth code
type OpenAIExchangeCodeRequest struct {
	SessionID   string `json:"session_id" binding:"required"`
	Code        string `json:"code" binding:"required"`
	State       string `json:"state" binding:"required"`
	RedirectURI string `json:"redirect_uri"`
	ProxyID     *int64 `json:"proxy_id"`
}

// ExchangeCode exchanges OpenAI authorization code for tokens
// POST /api/v1/admin/openai/exchange-code
func (h *OpenAIOAuthHandler) ExchangeCode(c *gin.Context) {
	var req OpenAIExchangeCodeRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "Invalid request: "+err.Error())
		return
	}

	tokenInfo, err := h.openaiOAuthService.ExchangeCode(c.Request.Context(), &service.OpenAIExchangeCodeInput{
		SessionID:   req.SessionID,
		Code:        req.Code,
		State:       req.State,
		RedirectURI: req.RedirectURI,
		ProxyID:     req.ProxyID,
	})
	if err != nil {
		response.ErrorFrom(c, err)
		return
	}

	response.Success(c, tokenInfo)
}

// OpenAIRefreshTokenRequest represents the request for refreshing OpenAI token
type OpenAIRefreshTokenRequest struct {
	RefreshToken string `json:"refresh_token"`
	RT           string `json:"rt"`
	ClientID     string `json:"client_id"`
	ProxyID      *int64 `json:"proxy_id"`
}

// RefreshToken refreshes an OpenAI OAuth token
// POST /api/v1/admin/openai/refresh-token
// POST /api/v1/admin/sora/rt2at
func (h *OpenAIOAuthHandler) RefreshToken(c *gin.Context) {
	var req OpenAIRefreshTokenRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "Invalid request: "+err.Error())
		return
	}
	refreshToken := strings.TrimSpace(req.RefreshToken)
	if refreshToken == "" {
		refreshToken = strings.TrimSpace(req.RT)
	}
	if refreshToken == "" {
		response.BadRequest(c, "refresh_token is required")
		return
	}

	var proxyURL string
	if req.ProxyID != nil {
		proxy, err := h.adminService.GetProxy(c.Request.Context(), *req.ProxyID)
		if err == nil && proxy != nil {
			proxyURL = proxy.URL()
		}
	}

	// 未指定 client_id 时，根据请求路径平台自动设置默认值，避免 repository 层盲猜
	clientID := strings.TrimSpace(req.ClientID)
	if clientID == "" {
		platform := oauthPlatformFromPath(c)
		clientID, _ = openai.OAuthClientConfigByPlatform(platform)
	}

	tokenInfo, err := h.openaiOAuthService.RefreshTokenWithClientID(c.Request.Context(), refreshToken, proxyURL, clientID)
	if err != nil {
		response.ErrorFrom(c, err)
		return
	}

	response.Success(c, tokenInfo)
}

// ExchangeSoraSessionToken exchanges Sora session token to access token
// POST /api/v1/admin/sora/st2at
func (h *OpenAIOAuthHandler) ExchangeSoraSessionToken(c *gin.Context) {
	var req struct {
		SessionToken string `json:"session_token"`
		ST           string `json:"st"`
		ProxyID      *int64 `json:"proxy_id"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "Invalid request: "+err.Error())
		return
	}

	sessionToken := strings.TrimSpace(req.SessionToken)
	if sessionToken == "" {
		sessionToken = strings.TrimSpace(req.ST)
	}
	if sessionToken == "" {
		response.BadRequest(c, "session_token is required")
		return
	}

	tokenInfo, err := h.openaiOAuthService.ExchangeSoraSessionToken(c.Request.Context(), sessionToken, req.ProxyID)
	if err != nil {
		response.ErrorFrom(c, err)
		return
	}
	response.Success(c, tokenInfo)
}

// RefreshAccountToken refreshes token for a specific OpenAI/Sora account
// POST /api/v1/admin/openai/accounts/:id/refresh
// POST /api/v1/admin/sora/accounts/:id/refresh
func (h *OpenAIOAuthHandler) RefreshAccountToken(c *gin.Context) {
	accountID, err := strconv.ParseInt(c.Param("id"), 10, 64)
	if err != nil {
		response.BadRequest(c, "Invalid account ID")
		return
	}

	// Get account
	account, err := h.adminService.GetAccount(c.Request.Context(), accountID)
	if err != nil {
		response.ErrorFrom(c, err)
		return
	}

	platform := oauthPlatformFromPath(c)
	if account.Platform != platform {
		response.BadRequest(c, "Account platform does not match OAuth endpoint")
		return
	}

	// Only refresh OAuth-based accounts
	if !account.IsOAuth() {
		response.BadRequest(c, "Cannot refresh non-OAuth account credentials")
		return
	}

	// Use OpenAI OAuth service to refresh token
	tokenInfo, err := h.openaiOAuthService.RefreshAccountToken(c.Request.Context(), account)
	if err != nil {
		response.ErrorFrom(c, err)
		return
	}

	// Build new credentials from token info
	newCredentials := h.openaiOAuthService.BuildAccountCredentials(tokenInfo)

	// Preserve non-token settings from existing credentials
	for k, v := range account.Credentials {
		if _, exists := newCredentials[k]; !exists {
			newCredentials[k] = v
		}
	}

	updatedAccount, err := h.adminService.UpdateAccount(c.Request.Context(), accountID, &service.UpdateAccountInput{
		Credentials: newCredentials,
	})
	if err != nil {
		response.ErrorFrom(c, err)
		return
	}

	response.Success(c, dto.AccountFromService(updatedAccount))
}

// CreateAccountFromOAuth creates a new OpenAI/Sora OAuth account from token info
// POST /api/v1/admin/openai/create-from-oauth
// POST /api/v1/admin/sora/create-from-oauth
func (h *OpenAIOAuthHandler) CreateAccountFromOAuth(c *gin.Context) {
	var req struct {
		SessionID   string  `json:"session_id" binding:"required"`
		Code        string  `json:"code" binding:"required"`
		State       string  `json:"state" binding:"required"`
		RedirectURI string  `json:"redirect_uri"`
		ProxyID     *int64  `json:"proxy_id"`
		Name        string  `json:"name"`
		Concurrency int     `json:"concurrency"`
		Priority    int     `json:"priority"`
		GroupIDs    []int64 `json:"group_ids"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		response.BadRequest(c, "Invalid request: "+err.Error())
		return
	}

	// Exchange code for tokens
	tokenInfo, err := h.openaiOAuthService.ExchangeCode(c.Request.Context(), &service.OpenAIExchangeCodeInput{
		SessionID:   req.SessionID,
		Code:        req.Code,
		State:       req.State,
		RedirectURI: req.RedirectURI,
		ProxyID:     req.ProxyID,
	})
	if err != nil {
		response.ErrorFrom(c, err)
		return
	}

	// Build credentials from token info
	credentials := h.openaiOAuthService.BuildAccountCredentials(tokenInfo)

	platform := oauthPlatformFromPath(c)

	// Use email as default name if not provided
	name := req.Name
	if name == "" && tokenInfo.Email != "" {
		name = tokenInfo.Email
	}
	if name == "" {
		if platform == service.PlatformSora {
			name = "Sora OAuth Account"
		} else {
			name = "OpenAI OAuth Account"
		}
	}

	// Create account
	account, err := h.adminService.CreateAccount(c.Request.Context(), &service.CreateAccountInput{
		Name:        name,
		Platform:    platform,
		Type:        "oauth",
		Credentials: credentials,
		ProxyID:     req.ProxyID,
		Concurrency: req.Concurrency,
		Priority:    req.Priority,
		GroupIDs:    req.GroupIDs,
	})
	if err != nil {
		response.ErrorFrom(c, err)
		return
	}

	response.Success(c, dto.AccountFromService(account))
}
