package service

import (
	"bufio"
	"bytes"
	"context"
	"crypto/rand"
	"encoding/hex"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"log"
	"net/http"
	"regexp"
	"strings"

	"github.com/Wei-Shaw/sub2api/internal/config"
	"github.com/Wei-Shaw/sub2api/internal/pkg/claude"
	"github.com/Wei-Shaw/sub2api/internal/pkg/geminicli"
	"github.com/Wei-Shaw/sub2api/internal/pkg/openai"
	"github.com/Wei-Shaw/sub2api/internal/util/urlvalidator"
	"github.com/gin-gonic/gin"
	"github.com/google/uuid"
)

// sseDataPrefix matches SSE data lines with optional whitespace after colon.
// Some upstream APIs return non-standard "data:" without space (should be "data: ").
var sseDataPrefix = regexp.MustCompile(`^data:\s*`)

const (
	testClaudeAPIURL   = "https://api.anthropic.com/v1/messages"
	chatgptCodexAPIURL = "https://chatgpt.com/backend-api/codex/responses"
)

// TestEvent represents a SSE event for account testing
type TestEvent struct {
	Type    string `json:"type"`
	Text    string `json:"text,omitempty"`
	Model   string `json:"model,omitempty"`
	Success bool   `json:"success,omitempty"`
	Error   string `json:"error,omitempty"`
}

// AccountTestService handles account testing operations
type AccountTestService struct {
	accountRepo               AccountRepository
	geminiTokenProvider       *GeminiTokenProvider
	antigravityGatewayService *AntigravityGatewayService
	httpUpstream              HTTPUpstream
	cfg                       *config.Config
}

// NewAccountTestService creates a new AccountTestService
func NewAccountTestService(
	accountRepo AccountRepository,
	geminiTokenProvider *GeminiTokenProvider,
	antigravityGatewayService *AntigravityGatewayService,
	httpUpstream HTTPUpstream,
	cfg *config.Config,
) *AccountTestService {
	return &AccountTestService{
		accountRepo:               accountRepo,
		geminiTokenProvider:       geminiTokenProvider,
		antigravityGatewayService: antigravityGatewayService,
		httpUpstream:              httpUpstream,
		cfg:                       cfg,
	}
}

func (s *AccountTestService) validateUpstreamBaseURL(raw string) (string, error) {
	if s.cfg == nil {
		return "", errors.New("config is not available")
	}
	if !s.cfg.Security.URLAllowlist.Enabled {
		return urlvalidator.ValidateURLFormat(raw, s.cfg.Security.URLAllowlist.AllowInsecureHTTP)
	}
	normalized, err := urlvalidator.ValidateHTTPSURL(raw, urlvalidator.ValidationOptions{
		AllowedHosts:     s.cfg.Security.URLAllowlist.UpstreamHosts,
		RequireAllowlist: true,
		AllowPrivate:     s.cfg.Security.URLAllowlist.AllowPrivateHosts,
	})
	if err != nil {
		return "", err
	}
	return normalized, nil
}

// generateSessionString generates a Claude Code style session string
func generateSessionString() (string, error) {
	bytes := make([]byte, 32)
	if _, err := rand.Read(bytes); err != nil {
		return "", err
	}
	hex64 := hex.EncodeToString(bytes)
	sessionUUID := uuid.New().String()
	return fmt.Sprintf("user_%s_account__session_%s", hex64, sessionUUID), nil
}

// createTestPayload creates a Claude Code style test request payload
func createTestPayload(modelID string) (map[string]any, error) {
	sessionID, err := generateSessionString()
	if err != nil {
		return nil, err
	}

	return map[string]any{
		"model": modelID,
		"messages": []map[string]any{
			{
				"role": "user",
				"content": []map[string]any{
					{
						"type": "text",
						"text": "hi",
						"cache_control": map[string]string{
							"type": "ephemeral",
						},
					},
				},
			},
		},
		"system": []map[string]any{
			{
				"type": "text",
				"text": claudeCodeSystemPrompt,
				"cache_control": map[string]string{
					"type": "ephemeral",
				},
			},
		},
		"metadata": map[string]string{
			"user_id": sessionID,
		},
		"max_tokens":  1024,
		"temperature": 1,
		"stream":      true,
	}, nil
}

// TestAccountConnection tests an account's connection by sending a test request
// All account types use full Claude Code client characteristics, only auth header differs
// modelID is optional - if empty, defaults to claude.DefaultTestModel
func (s *AccountTestService) TestAccountConnection(c *gin.Context, accountID int64, modelID string) error {
	ctx := c.Request.Context()

	// Get account
	account, err := s.accountRepo.GetByID(ctx, accountID)
	if err != nil {
		return s.sendErrorAndEnd(c, "Account not found")
	}

	// Route to platform-specific test method
	if account.IsOpenAI() {
		return s.testOpenAIAccountConnection(c, account, modelID)
	}

	if account.IsGemini() {
		return s.testGeminiAccountConnection(c, account, modelID)
	}

	if account.Platform == PlatformAntigravity {
		return s.testAntigravityAccountConnection(c, account, modelID)
	}

	return s.testClaudeAccountConnection(c, account, modelID)
}

// testClaudeAccountConnection tests an Anthropic Claude account's connection
func (s *AccountTestService) testClaudeAccountConnection(c *gin.Context, account *Account, modelID string) error {
	ctx := c.Request.Context()

	// Determine the model to use
	testModelID := modelID
	if testModelID == "" {
		testModelID = claude.DefaultTestModel
	}

	// For API Key accounts with model mapping, map the model
	if account.Type == "apikey" {
		mapping := account.GetModelMapping()
		if len(mapping) > 0 {
			if mappedModel, exists := mapping[testModelID]; exists {
				testModelID = mappedModel
			}
		}
	}

	// Determine authentication method and API URL
	var authToken string
	var useBearer bool
	var apiURL string

	if account.IsOAuth() {
		// OAuth or Setup Token - use Bearer token
		useBearer = true
		apiURL = testClaudeAPIURL
		authToken = account.GetCredential("access_token")
		if authToken == "" {
			return s.sendErrorAndEnd(c, "No access token available")
		}
	} else if account.Type == "apikey" {
		// API Key - use x-api-key header
		useBearer = false
		authToken = account.GetCredential("api_key")
		if authToken == "" {
			return s.sendErrorAndEnd(c, "No API key available")
		}

		baseURL := account.GetBaseURL()
		if baseURL == "" {
			baseURL = "https://api.anthropic.com"
		}
		normalizedBaseURL, err := s.validateUpstreamBaseURL(baseURL)
		if err != nil {
			return s.sendErrorAndEnd(c, fmt.Sprintf("Invalid base URL: %s", err.Error()))
		}
		apiURL = strings.TrimSuffix(normalizedBaseURL, "/") + "/v1/messages"
	} else {
		return s.sendErrorAndEnd(c, fmt.Sprintf("Unsupported account type: %s", account.Type))
	}

	// Set SSE headers
	c.Writer.Header().Set("Content-Type", "text/event-stream")
	c.Writer.Header().Set("Cache-Control", "no-cache")
	c.Writer.Header().Set("Connection", "keep-alive")
	c.Writer.Header().Set("X-Accel-Buffering", "no")
	c.Writer.Flush()

	// Create Claude Code style payload (same for all account types)
	payload, err := createTestPayload(testModelID)
	if err != nil {
		return s.sendErrorAndEnd(c, "Failed to create test payload")
	}
	payloadBytes, _ := json.Marshal(payload)

	// Send test_start event
	s.sendEvent(c, TestEvent{Type: "test_start", Model: testModelID})

	req, err := http.NewRequestWithContext(ctx, "POST", apiURL, bytes.NewReader(payloadBytes))
	if err != nil {
		return s.sendErrorAndEnd(c, "Failed to create request")
	}

	// Set common headers
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("anthropic-version", "2023-06-01")

	// Set authentication header and beta header based on account type
	if useBearer {
		// OAuth 账号使用完整的 Claude Code beta header
		req.Header.Set("anthropic-beta", claude.DefaultBetaHeader)
		req.Header.Set("Authorization", "Bearer "+authToken)
		// Apply Claude Code client headers for OAuth
		for key, value := range claude.DefaultHeaders {
			req.Header.Set(key, value)
		}
	} else {
		// API Key 账号使用简化的 beta header（不含 oauth）
		req.Header.Set("anthropic-beta", claude.APIKeyBetaHeader)
		req.Header.Set("x-api-key", authToken)
	}

	// Get proxy URL
	proxyURL := ""
	if account.ProxyID != nil && account.Proxy != nil {
		proxyURL = account.Proxy.URL()
	}

	resp, err := s.httpUpstream.DoWithTLS(req, proxyURL, account.ID, account.Concurrency, account.IsTLSFingerprintEnabled())
	if err != nil {
		return s.sendErrorAndEnd(c, fmt.Sprintf("Request failed: %s", err.Error()))
	}
	defer func() { _ = resp.Body.Close() }()

	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		return s.sendErrorAndEnd(c, fmt.Sprintf("API returned %d: %s", resp.StatusCode, string(body)))
	}

	// Process SSE stream
	return s.processClaudeStream(c, resp.Body)
}

// testOpenAIAccountConnection tests an OpenAI account's connection
func (s *AccountTestService) testOpenAIAccountConnection(c *gin.Context, account *Account, modelID string) error {
	ctx := c.Request.Context()

	// Default to openai.DefaultTestModel for OpenAI testing
	testModelID := modelID
	if testModelID == "" {
		testModelID = openai.DefaultTestModel
	}

	// For API Key accounts with model mapping, map the model
	if account.Type == "apikey" {
		mapping := account.GetModelMapping()
		if len(mapping) > 0 {
			if mappedModel, exists := mapping[testModelID]; exists {
				testModelID = mappedModel
			}
		}
	}

	// Determine authentication method and API URL
	var authToken string
	var apiURL string
	var isOAuth bool
	var chatgptAccountID string

	if account.IsOAuth() {
		isOAuth = true
		// OAuth - use Bearer token with ChatGPT internal API
		authToken = account.GetOpenAIAccessToken()
		if authToken == "" {
			return s.sendErrorAndEnd(c, "No access token available")
		}

		// OAuth uses ChatGPT internal API
		apiURL = chatgptCodexAPIURL
		chatgptAccountID = account.GetChatGPTAccountID()
	} else if account.Type == "apikey" {
		// API Key - use Platform API
		authToken = account.GetOpenAIApiKey()
		if authToken == "" {
			return s.sendErrorAndEnd(c, "No API key available")
		}

		baseURL := account.GetOpenAIBaseURL()
		if baseURL == "" {
			baseURL = "https://api.openai.com"
		}
		normalizedBaseURL, err := s.validateUpstreamBaseURL(baseURL)
		if err != nil {
			return s.sendErrorAndEnd(c, fmt.Sprintf("Invalid base URL: %s", err.Error()))
		}
		apiURL = strings.TrimSuffix(normalizedBaseURL, "/") + "/responses"
	} else {
		return s.sendErrorAndEnd(c, fmt.Sprintf("Unsupported account type: %s", account.Type))
	}

	// Set SSE headers
	c.Writer.Header().Set("Content-Type", "text/event-stream")
	c.Writer.Header().Set("Cache-Control", "no-cache")
	c.Writer.Header().Set("Connection", "keep-alive")
	c.Writer.Header().Set("X-Accel-Buffering", "no")
	c.Writer.Flush()

	// Create OpenAI Responses API payload
	payload := createOpenAITestPayload(testModelID, isOAuth)
	payloadBytes, _ := json.Marshal(payload)

	// Send test_start event
	s.sendEvent(c, TestEvent{Type: "test_start", Model: testModelID})

	req, err := http.NewRequestWithContext(ctx, "POST", apiURL, bytes.NewReader(payloadBytes))
	if err != nil {
		return s.sendErrorAndEnd(c, "Failed to create request")
	}

	// Set common headers
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", "Bearer "+authToken)

	// Set OAuth-specific headers for ChatGPT internal API
	if isOAuth {
		req.Host = "chatgpt.com"
		req.Header.Set("accept", "text/event-stream")
		if chatgptAccountID != "" {
			req.Header.Set("chatgpt-account-id", chatgptAccountID)
		}
	}

	// Get proxy URL
	proxyURL := ""
	if account.ProxyID != nil && account.Proxy != nil {
		proxyURL = account.Proxy.URL()
	}

	resp, err := s.httpUpstream.DoWithTLS(req, proxyURL, account.ID, account.Concurrency, account.IsTLSFingerprintEnabled())
	if err != nil {
		return s.sendErrorAndEnd(c, fmt.Sprintf("Request failed: %s", err.Error()))
	}
	defer func() { _ = resp.Body.Close() }()

	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		return s.sendErrorAndEnd(c, fmt.Sprintf("API returned %d: %s", resp.StatusCode, string(body)))
	}

	// Process SSE stream
	return s.processOpenAIStream(c, resp.Body)
}

// testGeminiAccountConnection tests a Gemini account's connection
func (s *AccountTestService) testGeminiAccountConnection(c *gin.Context, account *Account, modelID string) error {
	ctx := c.Request.Context()

	// Determine the model to use
	testModelID := modelID
	if testModelID == "" {
		testModelID = geminicli.DefaultTestModel
	}

	// For API Key accounts with model mapping, map the model
	if account.Type == AccountTypeAPIKey {
		mapping := account.GetModelMapping()
		if len(mapping) > 0 {
			if mappedModel, exists := mapping[testModelID]; exists {
				testModelID = mappedModel
			}
		}
	}

	// Set SSE headers
	c.Writer.Header().Set("Content-Type", "text/event-stream")
	c.Writer.Header().Set("Cache-Control", "no-cache")
	c.Writer.Header().Set("Connection", "keep-alive")
	c.Writer.Header().Set("X-Accel-Buffering", "no")
	c.Writer.Flush()

	// Create test payload (Gemini format)
	payload := createGeminiTestPayload()

	// Build request based on account type
	var req *http.Request
	var err error

	switch account.Type {
	case AccountTypeAPIKey:
		req, err = s.buildGeminiAPIKeyRequest(ctx, account, testModelID, payload)
	case AccountTypeOAuth:
		req, err = s.buildGeminiOAuthRequest(ctx, account, testModelID, payload)
	default:
		return s.sendErrorAndEnd(c, fmt.Sprintf("Unsupported account type: %s", account.Type))
	}

	if err != nil {
		return s.sendErrorAndEnd(c, fmt.Sprintf("Failed to build request: %s", err.Error()))
	}

	// Send test_start event
	s.sendEvent(c, TestEvent{Type: "test_start", Model: testModelID})

	// Get proxy and execute request
	proxyURL := ""
	if account.ProxyID != nil && account.Proxy != nil {
		proxyURL = account.Proxy.URL()
	}

	resp, err := s.httpUpstream.DoWithTLS(req, proxyURL, account.ID, account.Concurrency, account.IsTLSFingerprintEnabled())
	if err != nil {
		return s.sendErrorAndEnd(c, fmt.Sprintf("Request failed: %s", err.Error()))
	}
	defer func() { _ = resp.Body.Close() }()

	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		return s.sendErrorAndEnd(c, fmt.Sprintf("API returned %d: %s", resp.StatusCode, string(body)))
	}

	// Process SSE stream
	return s.processGeminiStream(c, resp.Body)
}

// testAntigravityAccountConnection tests an Antigravity account's connection
// 支持 Claude 和 Gemini 两种协议，使用非流式请求
func (s *AccountTestService) testAntigravityAccountConnection(c *gin.Context, account *Account, modelID string) error {
	ctx := c.Request.Context()

	// 默认模型：Claude 使用 claude-sonnet-4-5，Gemini 使用 gemini-3-pro-preview
	testModelID := modelID
	if testModelID == "" {
		testModelID = "claude-sonnet-4-5"
	}

	if s.antigravityGatewayService == nil {
		return s.sendErrorAndEnd(c, "Antigravity gateway service not configured")
	}

	// Set SSE headers
	c.Writer.Header().Set("Content-Type", "text/event-stream")
	c.Writer.Header().Set("Cache-Control", "no-cache")
	c.Writer.Header().Set("Connection", "keep-alive")
	c.Writer.Header().Set("X-Accel-Buffering", "no")
	c.Writer.Flush()

	// Send test_start event
	s.sendEvent(c, TestEvent{Type: "test_start", Model: testModelID})

	// 调用 AntigravityGatewayService.TestConnection（复用协议转换逻辑）
	result, err := s.antigravityGatewayService.TestConnection(ctx, account, testModelID)
	if err != nil {
		return s.sendErrorAndEnd(c, err.Error())
	}

	// 发送响应内容
	if result.Text != "" {
		s.sendEvent(c, TestEvent{Type: "content", Text: result.Text})
	}

	s.sendEvent(c, TestEvent{Type: "test_complete", Success: true})
	return nil
}

// buildGeminiAPIKeyRequest builds request for Gemini API Key accounts
func (s *AccountTestService) buildGeminiAPIKeyRequest(ctx context.Context, account *Account, modelID string, payload []byte) (*http.Request, error) {
	apiKey := account.GetCredential("api_key")
	if strings.TrimSpace(apiKey) == "" {
		return nil, fmt.Errorf("no API key available")
	}

	baseURL := account.GetCredential("base_url")
	if baseURL == "" {
		baseURL = geminicli.AIStudioBaseURL
	}
	normalizedBaseURL, err := s.validateUpstreamBaseURL(baseURL)
	if err != nil {
		return nil, err
	}

	// Use streamGenerateContent for real-time feedback
	fullURL := fmt.Sprintf("%s/v1beta/models/%s:streamGenerateContent?alt=sse",
		strings.TrimRight(normalizedBaseURL, "/"), modelID)

	req, err := http.NewRequestWithContext(ctx, "POST", fullURL, bytes.NewReader(payload))
	if err != nil {
		return nil, err
	}

	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("x-goog-api-key", apiKey)

	return req, nil
}

// buildGeminiOAuthRequest builds request for Gemini OAuth accounts
func (s *AccountTestService) buildGeminiOAuthRequest(ctx context.Context, account *Account, modelID string, payload []byte) (*http.Request, error) {
	if s.geminiTokenProvider == nil {
		return nil, fmt.Errorf("gemini token provider not configured")
	}

	// Get access token (auto-refreshes if needed)
	accessToken, err := s.geminiTokenProvider.GetAccessToken(ctx, account)
	if err != nil {
		return nil, fmt.Errorf("failed to get access token: %w", err)
	}

	projectID := strings.TrimSpace(account.GetCredential("project_id"))
	if projectID == "" {
		// AI Studio OAuth mode (no project_id): call generativelanguage API directly with Bearer token.
		baseURL := account.GetCredential("base_url")
		if strings.TrimSpace(baseURL) == "" {
			baseURL = geminicli.AIStudioBaseURL
		}
		normalizedBaseURL, err := s.validateUpstreamBaseURL(baseURL)
		if err != nil {
			return nil, err
		}
		fullURL := fmt.Sprintf("%s/v1beta/models/%s:streamGenerateContent?alt=sse", strings.TrimRight(normalizedBaseURL, "/"), modelID)

		req, err := http.NewRequestWithContext(ctx, http.MethodPost, fullURL, bytes.NewReader(payload))
		if err != nil {
			return nil, err
		}
		req.Header.Set("Content-Type", "application/json")
		req.Header.Set("Authorization", "Bearer "+accessToken)
		return req, nil
	}

	// Code Assist mode (with project_id)
	return s.buildCodeAssistRequest(ctx, accessToken, projectID, modelID, payload)
}

// buildCodeAssistRequest builds request for Google Code Assist API (used by Gemini CLI and Antigravity)
func (s *AccountTestService) buildCodeAssistRequest(ctx context.Context, accessToken, projectID, modelID string, payload []byte) (*http.Request, error) {
	var inner map[string]any
	if err := json.Unmarshal(payload, &inner); err != nil {
		return nil, err
	}

	wrapped := map[string]any{
		"model":   modelID,
		"project": projectID,
		"request": inner,
	}
	wrappedBytes, _ := json.Marshal(wrapped)

	normalizedBaseURL, err := s.validateUpstreamBaseURL(geminicli.GeminiCliBaseURL)
	if err != nil {
		return nil, err
	}
	fullURL := fmt.Sprintf("%s/v1internal:streamGenerateContent?alt=sse", normalizedBaseURL)

	req, err := http.NewRequestWithContext(ctx, "POST", fullURL, bytes.NewReader(wrappedBytes))
	if err != nil {
		return nil, err
	}

	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", "Bearer "+accessToken)
	req.Header.Set("User-Agent", geminicli.GeminiCLIUserAgent)

	return req, nil
}

// createGeminiTestPayload creates a minimal test payload for Gemini API
func createGeminiTestPayload() []byte {
	payload := map[string]any{
		"contents": []map[string]any{
			{
				"role": "user",
				"parts": []map[string]any{
					{"text": "hi"},
				},
			},
		},
		"systemInstruction": map[string]any{
			"parts": []map[string]any{
				{"text": "You are a helpful AI assistant."},
			},
		},
	}
	bytes, _ := json.Marshal(payload)
	return bytes
}

// processGeminiStream processes SSE stream from Gemini API
func (s *AccountTestService) processGeminiStream(c *gin.Context, body io.Reader) error {
	reader := bufio.NewReader(body)

	for {
		line, err := reader.ReadString('\n')
		if err != nil {
			if err == io.EOF {
				s.sendEvent(c, TestEvent{Type: "test_complete", Success: true})
				return nil
			}
			return s.sendErrorAndEnd(c, fmt.Sprintf("Stream read error: %s", err.Error()))
		}

		line = strings.TrimSpace(line)
		if line == "" || !strings.HasPrefix(line, "data: ") {
			continue
		}

		jsonStr := strings.TrimPrefix(line, "data: ")
		if jsonStr == "[DONE]" {
			s.sendEvent(c, TestEvent{Type: "test_complete", Success: true})
			return nil
		}

		var data map[string]any
		if err := json.Unmarshal([]byte(jsonStr), &data); err != nil {
			continue
		}

		// Support two Gemini response formats:
		// - AI Studio: {"candidates": [...]}
		// - Gemini CLI: {"response": {"candidates": [...]}}
		if resp, ok := data["response"].(map[string]any); ok && resp != nil {
			data = resp
		}
		if candidates, ok := data["candidates"].([]any); ok && len(candidates) > 0 {
			if candidate, ok := candidates[0].(map[string]any); ok {
				// Extract content first (before checking completion)
				if content, ok := candidate["content"].(map[string]any); ok {
					if parts, ok := content["parts"].([]any); ok {
						for _, part := range parts {
							if partMap, ok := part.(map[string]any); ok {
								if text, ok := partMap["text"].(string); ok && text != "" {
									s.sendEvent(c, TestEvent{Type: "content", Text: text})
								}
							}
						}
					}
				}

				// Check for completion after extracting content
				if finishReason, ok := candidate["finishReason"].(string); ok && finishReason != "" {
					s.sendEvent(c, TestEvent{Type: "test_complete", Success: true})
					return nil
				}
			}
		}

		// Handle errors
		if errData, ok := data["error"].(map[string]any); ok {
			errorMsg := "Unknown error"
			if msg, ok := errData["message"].(string); ok {
				errorMsg = msg
			}
			return s.sendErrorAndEnd(c, errorMsg)
		}
	}
}

// createOpenAITestPayload creates a test payload for OpenAI Responses API
func createOpenAITestPayload(modelID string, isOAuth bool) map[string]any {
	payload := map[string]any{
		"model": modelID,
		"input": []map[string]any{
			{
				"role": "user",
				"content": []map[string]any{
					{
						"type": "input_text",
						"text": "hi",
					},
				},
			},
		},
		"stream": true,
	}

	// OAuth accounts using ChatGPT internal API require store: false
	if isOAuth {
		payload["store"] = false
	}

	// All accounts require instructions for Responses API
	payload["instructions"] = openai.DefaultInstructions

	return payload
}

// processClaudeStream processes the SSE stream from Claude API
func (s *AccountTestService) processClaudeStream(c *gin.Context, body io.Reader) error {
	reader := bufio.NewReader(body)

	for {
		line, err := reader.ReadString('\n')
		if err != nil {
			if err == io.EOF {
				s.sendEvent(c, TestEvent{Type: "test_complete", Success: true})
				return nil
			}
			return s.sendErrorAndEnd(c, fmt.Sprintf("Stream read error: %s", err.Error()))
		}

		line = strings.TrimSpace(line)
		if line == "" || !sseDataPrefix.MatchString(line) {
			continue
		}

		jsonStr := sseDataPrefix.ReplaceAllString(line, "")
		if jsonStr == "[DONE]" {
			s.sendEvent(c, TestEvent{Type: "test_complete", Success: true})
			return nil
		}

		var data map[string]any
		if err := json.Unmarshal([]byte(jsonStr), &data); err != nil {
			continue
		}

		eventType, _ := data["type"].(string)

		switch eventType {
		case "content_block_delta":
			if delta, ok := data["delta"].(map[string]any); ok {
				if text, ok := delta["text"].(string); ok {
					s.sendEvent(c, TestEvent{Type: "content", Text: text})
				}
			}
		case "message_stop":
			s.sendEvent(c, TestEvent{Type: "test_complete", Success: true})
			return nil
		case "error":
			errorMsg := "Unknown error"
			if errData, ok := data["error"].(map[string]any); ok {
				if msg, ok := errData["message"].(string); ok {
					errorMsg = msg
				}
			}
			return s.sendErrorAndEnd(c, errorMsg)
		}
	}
}

// processOpenAIStream processes the SSE stream from OpenAI Responses API
func (s *AccountTestService) processOpenAIStream(c *gin.Context, body io.Reader) error {
	reader := bufio.NewReader(body)

	for {
		line, err := reader.ReadString('\n')
		if err != nil {
			if err == io.EOF {
				s.sendEvent(c, TestEvent{Type: "test_complete", Success: true})
				return nil
			}
			return s.sendErrorAndEnd(c, fmt.Sprintf("Stream read error: %s", err.Error()))
		}

		line = strings.TrimSpace(line)
		if line == "" || !sseDataPrefix.MatchString(line) {
			continue
		}

		jsonStr := sseDataPrefix.ReplaceAllString(line, "")
		if jsonStr == "[DONE]" {
			s.sendEvent(c, TestEvent{Type: "test_complete", Success: true})
			return nil
		}

		var data map[string]any
		if err := json.Unmarshal([]byte(jsonStr), &data); err != nil {
			continue
		}

		eventType, _ := data["type"].(string)

		switch eventType {
		case "response.output_text.delta":
			// OpenAI Responses API uses "delta" field for text content
			if delta, ok := data["delta"].(string); ok && delta != "" {
				s.sendEvent(c, TestEvent{Type: "content", Text: delta})
			}
		case "response.completed":
			s.sendEvent(c, TestEvent{Type: "test_complete", Success: true})
			return nil
		case "error":
			errorMsg := "Unknown error"
			if errData, ok := data["error"].(map[string]any); ok {
				if msg, ok := errData["message"].(string); ok {
					errorMsg = msg
				}
			}
			return s.sendErrorAndEnd(c, errorMsg)
		}
	}
}

// sendEvent sends a SSE event to the client
func (s *AccountTestService) sendEvent(c *gin.Context, event TestEvent) {
	eventJSON, _ := json.Marshal(event)
	if _, err := fmt.Fprintf(c.Writer, "data: %s\n\n", eventJSON); err != nil {
		log.Printf("failed to write SSE event: %v", err)
		return
	}
	c.Writer.Flush()
}

// sendErrorAndEnd sends an error event and ends the stream
func (s *AccountTestService) sendErrorAndEnd(c *gin.Context, errorMsg string) error {
	log.Printf("Account test error: %s", errorMsg)
	s.sendEvent(c, TestEvent{Type: "error", Error: errorMsg})
	return fmt.Errorf("%s", errorMsg)
}
