package executor

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"net/http"
	"strings"
	"time"

	codexauth "github.com/router-for-me/CLIProxyAPI/v6/internal/auth/codex"
	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
	"github.com/router-for-me/CLIProxyAPI/v6/internal/thinking"
	"github.com/router-for-me/CLIProxyAPI/v6/internal/util"
	cliproxyauth "github.com/router-for-me/CLIProxyAPI/v6/sdk/cliproxy/auth"
	cliproxyexecutor "github.com/router-for-me/CLIProxyAPI/v6/sdk/cliproxy/executor"
	sdktranslator "github.com/router-for-me/CLIProxyAPI/v6/sdk/translator"
	log "github.com/sirupsen/logrus"
	"github.com/tidwall/gjson"
	"github.com/tidwall/sjson"
	"github.com/tiktoken-go/tokenizer"
)

// CodexExecutorRefactored is a stateless executor for Codex (OpenAI Responses API).
type CodexExecutorRefactored struct {
	cfg  *config.Config
	base *BaseExecutor
}

// NewCodexExecutorRefactored creates a new Codex executor instance.
func NewCodexExecutorRefactored(cfg *config.Config) *CodexExecutorRefactored {
	provider := NewCodexProvider(cfg)
	return &CodexExecutorRefactored{
		cfg:  cfg,
		base: NewBaseExecutor(cfg, provider),
	}
}

// Identifier returns the executor identifier.
func (e *CodexExecutorRefactored) Identifier() string { return "codex" }

// PrepareRequest injects Codex credentials into the outgoing HTTP request.
func (e *CodexExecutorRefactored) PrepareRequest(req *http.Request, auth *cliproxyauth.Auth) error {
	if req == nil {
		return nil
	}
	apiKey, _ := codexCreds(auth)
	if strings.TrimSpace(apiKey) != "" {
		req.Header.Set("Authorization", "Bearer "+apiKey)
	}
	var attrs map[string]string
	if auth != nil {
		attrs = auth.Attributes
	}
	util.ApplyCustomHeadersFromAttrs(req, attrs)
	return nil
}

// HttpRequest injects Codex credentials into the request and executes it.
func (e *CodexExecutorRefactored) HttpRequest(ctx context.Context, auth *cliproxyauth.Auth, req *http.Request) (*http.Response, error) {
	if req == nil {
		return nil, fmt.Errorf("codex executor: request is nil")
	}
	if ctx == nil {
		ctx = req.Context()
	}
	httpReq := req.WithContext(ctx)
	if err := e.PrepareRequest(httpReq, auth); err != nil {
		return nil, err
	}
	httpClient := newProxyAwareHTTPClient(ctx, e.cfg, auth, 0)
	return httpClient.Do(httpReq)
}

// Execute performs a non-streaming request to the Codex API.
func (e *CodexExecutorRefactored) Execute(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (resp cliproxyexecutor.Response, err error) {
	if cfg := parseCodexAgentConfig(req.Payload); cfg.Enabled() && opts.Alt == "responses/compact" {
		return cliproxyexecutor.Response{}, statusErr{code: http.StatusBadRequest, msg: "codex agent_mode is not supported for /responses/compact"}
	}
	if opts.Alt == "responses/compact" {
		return e.executeCompact(ctx, auth, req, opts)
	}

	// Codex always uses streaming internally, then converts to non-streaming
	return e.executeViaStream(ctx, auth, req, opts)
}

// executeViaStream executes a non-streaming request by consuming a stream
func (e *CodexExecutorRefactored) executeViaStream(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (resp cliproxyexecutor.Response, err error) {
	baseModel := thinking.ParseSuffix(req.Model).ModelName
	apiKey, baseURL := codexCreds(auth)
	if baseURL == "" {
		baseURL = codexDefaultURL
	}

	reporter := newUsageReporter(ctx, e.Identifier(), baseModel, auth)
	defer reporter.trackFailure(ctx, &err)

	from := opts.SourceFormat
	to := sdktranslator.FromString("codex")
	originalPayloadSource := req.Payload
	if len(opts.OriginalRequest) > 0 {
		originalPayloadSource = opts.OriginalRequest
	}
	originalPayload := bytes.Clone(originalPayloadSource)
	originalTranslated := sdktranslator.TranslateRequest(from, to, baseModel, originalPayload, false)
	body := sdktranslator.TranslateRequest(from, to, baseModel, bytes.Clone(req.Payload), false)

	body, err = thinking.ApplyThinking(body, req.Model, from.String(), to.String(), e.Identifier())
	if err != nil {
		return resp, err
	}

	requestedModel := payloadRequestedModel(opts, req.Model)
	body = applyPayloadConfigWithRoot(e.cfg, baseModel, to.String(), "", body, originalTranslated, requestedModel)
	agentCfg := resolveCodexAgentConfigForNonStream(body, req.Payload)
	body, err = normalizeCodexRequestBody(body, baseModel, true)
	if err != nil {
		return resp, err
	}

	var pass codexCompletedPassResult
	switch agentCfg.Mode {
	case codexAgentModePlannerReviewer:
		pass, err = e.executeCodexPlannerReviewerPipeline(ctx, auth, apiKey, baseURL, from, req, body)
	default:
		url := strings.TrimSuffix(baseURL, "/") + "/responses"
		pass, err = e.executeCodexCompletedHTTPPass(ctx, auth, apiKey, url, from, req, body, true)
	}
	if err != nil {
		return resp, err
	}
	if pass.UsageOK {
		reporter.publish(ctx, pass.Usage)
	}

	reqBodyForTranslation := body
	if len(pass.Request) > 0 {
		reqBodyForTranslation = pass.Request
	}
	var param any
	out := sdktranslator.TranslateNonStream(ctx, to, from, req.Model, originalPayload, reqBodyForTranslation, pass.Completed, &param)
	resp = cliproxyexecutor.Response{Payload: []byte(out), Headers: pass.Headers}
	return resp, nil
}

// executeCompact handles the /responses/compact endpoint
func (e *CodexExecutorRefactored) executeCompact(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (resp cliproxyexecutor.Response, err error) {
	baseModel := thinking.ParseSuffix(req.Model).ModelName
	apiKey, baseURL := codexCreds(auth)
	if baseURL == "" {
		baseURL = codexDefaultURL
	}

	reporter := newUsageReporter(ctx, e.Identifier(), baseModel, auth)
	defer reporter.trackFailure(ctx, &err)

	from := opts.SourceFormat
	to := sdktranslator.FromString("openai-response")
	originalPayloadSource := req.Payload
	if len(opts.OriginalRequest) > 0 {
		originalPayloadSource = opts.OriginalRequest
	}
	originalPayload := bytes.Clone(originalPayloadSource)
	originalTranslated := sdktranslator.TranslateRequest(from, to, baseModel, originalPayload, false)
	body := sdktranslator.TranslateRequest(from, to, baseModel, bytes.Clone(req.Payload), false)

	body, err = thinking.ApplyThinking(body, req.Model, from.String(), to.String(), e.Identifier())
	if err != nil {
		return resp, err
	}

	requestedModel := payloadRequestedModel(opts, req.Model)
	body = applyPayloadConfigWithRoot(e.cfg, baseModel, to.String(), "", body, originalTranslated, requestedModel)
	body, err = normalizeCodexRequestBody(body, baseModel, false)
	if err != nil {
		return resp, err
	}
	body, _ = sjson.DeleteBytes(body, "stream")

	url := strings.TrimSuffix(baseURL, "/") + "/responses/compact"
	httpReq, err := e.cacheHelper(ctx, from, url, req, body)
	if err != nil {
		return resp, err
	}

	provider := NewCodexProvider(e.cfg)
	provider.ApplyHeaders(httpReq, auth, apiKey, false)

	var authID, authLabel, authType, authValue string
	if auth != nil {
		authID = auth.ID
		authLabel = auth.Label
		authType, authValue = auth.AccountInfo()
	}
	recordAPIRequest(ctx, e.cfg, upstreamRequestLog{
		URL:       url,
		Method:    http.MethodPost,
		Headers:   httpReq.Header.Clone(),
		Body:      body,
		Provider:  e.Identifier(),
		AuthID:    authID,
		AuthLabel: authLabel,
		AuthType:  authType,
		AuthValue: authValue,
	})

	httpClient := newProxyAwareHTTPClient(ctx, e.cfg, auth, 0)
	httpResp, err := httpClient.Do(httpReq)
	if err != nil {
		recordAPIResponseError(ctx, e.cfg, err)
		return resp, err
	}
	defer httpResp.Body.Close()

	recordAPIResponseMetadata(ctx, e.cfg, httpResp.StatusCode, httpResp.Header.Clone())
	if httpResp.StatusCode < 200 || httpResp.StatusCode >= 300 {
		b, _ := io.ReadAll(httpResp.Body)
		appendAPIResponseChunk(ctx, e.cfg, b)
		logWithRequestID(ctx).Debugf("request error, error status: %d, error message: %s", httpResp.StatusCode, summarizeErrorBody(httpResp.Header.Get("Content-Type"), b))
		return resp, statusErr{code: httpResp.StatusCode, msg: string(b)}
	}

	data, err := io.ReadAll(httpResp.Body)
	if err != nil {
		recordAPIResponseError(ctx, e.cfg, err)
		return resp, err
	}
	appendAPIResponseChunk(ctx, e.cfg, data)
	reporter.publish(ctx, parseOpenAIUsage(data))
	reporter.ensurePublished(ctx)

	var param any
	out := sdktranslator.TranslateNonStream(ctx, to, from, req.Model, originalPayload, body, data, &param)
	resp = cliproxyexecutor.Response{Payload: []byte(out), Headers: httpResp.Header.Clone()}
	return resp, nil
}

// ExecuteStream performs a streaming request to the Codex API.
func (e *CodexExecutorRefactored) ExecuteStream(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (*cliproxyexecutor.StreamResult, error) {
	if opts.Alt == "responses/compact" {
		return nil, statusErr{code: http.StatusBadRequest, msg: "streaming not supported for /responses/compact"}
	}
	if cfg := parseCodexAgentConfig(req.Payload); cfg.Enabled() {
		return nil, statusErr{code: http.StatusBadRequest, msg: "codex agent_mode is not supported for streaming requests"}
	}

	return e.base.ExecuteStream(ctx, auth, req, opts)
}

// CountTokens estimates token count for Codex requests.
func (e *CodexExecutorRefactored) CountTokens(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (cliproxyexecutor.Response, error) {
	baseModel := thinking.ParseSuffix(req.Model).ModelName

	from := opts.SourceFormat
	to := sdktranslator.FromString("codex")
	body := sdktranslator.TranslateRequest(from, to, baseModel, req.Payload, false)

	body, err := thinking.ApplyThinking(body, req.Model, from.String(), to.String(), e.Identifier())
	if err != nil {
		return cliproxyexecutor.Response{}, err
	}

	body, err = normalizeCodexRequestBody(body, baseModel, false)
	if err != nil {
		return cliproxyexecutor.Response{}, err
	}

	enc, err := tokenizerForCodexModel(baseModel)
	if err != nil {
		return cliproxyexecutor.Response{}, fmt.Errorf("codex executor: tokenizer init failed: %w", err)
	}

	count, err := countCodexInputTokens(enc, body)
	if err != nil {
		return cliproxyexecutor.Response{}, fmt.Errorf("codex executor: token counting failed: %w", err)
	}

	usageJSON := fmt.Sprintf(`{"response":{"usage":{"input_tokens":%d,"output_tokens":0,"total_tokens":%d}}}`, count, count)
	translated := sdktranslator.TranslateTokenCount(ctx, to, from, count, []byte(usageJSON))
	return cliproxyexecutor.Response{Payload: []byte(translated)}, nil
}

// Refresh refreshes the Codex authentication tokens.
func (e *CodexExecutorRefactored) Refresh(ctx context.Context, auth *cliproxyauth.Auth) (*cliproxyauth.Auth, error) {
	log.Debugf("codex executor: refresh called")
	if auth == nil {
		return nil, statusErr{code: 500, msg: "codex executor: auth is nil"}
	}
	var refreshToken string
	if auth.Metadata != nil {
		if v, ok := auth.Metadata["refresh_token"].(string); ok && v != "" {
			refreshToken = v
		}
	}
	if refreshToken == "" {
		return auth, nil
	}
	svc := codexauth.NewCodexAuth(e.cfg)
	td, err := svc.RefreshTokensWithRetry(ctx, refreshToken, 3)
	if err != nil {
		return nil, err
	}
	if auth.Metadata == nil {
		auth.Metadata = make(map[string]any)
	}
	auth.Metadata["id_token"] = td.IDToken
	auth.Metadata["access_token"] = td.AccessToken
	if td.RefreshToken != "" {
		auth.Metadata["refresh_token"] = td.RefreshToken
	}
	if td.AccountID != "" {
		auth.Metadata["account_id"] = td.AccountID
	}
	auth.Metadata["email"] = td.Email
	auth.Metadata["expired"] = td.Expire
	auth.Metadata["type"] = "codex"
	now := time.Now().Format(time.RFC3339)
	auth.Metadata["last_refresh"] = now
	return auth, nil
}

// cacheHelper applies cache-related logic to the request.
func (e *CodexExecutorRefactored) cacheHelper(ctx context.Context, from sdktranslator.Format, url string, req cliproxyexecutor.Request, rawJSON []byte) (*http.Request, error) {
	rawJSON, _, cacheHeaders := applyCodexPromptCache(e.cfg, from, req.Payload, req.Model, rawJSON, false)

	httpReq, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(rawJSON))
	if err != nil {
		return nil, err
	}

	for k, values := range cacheHeaders {
		for i := range values {
			httpReq.Header.Add(k, values[i])
		}
	}

	return httpReq, nil
}

func tokenizerForCodexModel(model string) (tokenizer.Codec, error) {
	sanitized := strings.ToLower(strings.TrimSpace(model))
	switch {
	case sanitized == "":
		return tokenizer.Get(tokenizer.Cl100kBase)
	case strings.HasPrefix(sanitized, "gpt-5"):
		return tokenizer.ForModel(tokenizer.GPT5)
	case strings.HasPrefix(sanitized, "gpt-4.1"):
		return tokenizer.ForModel(tokenizer.GPT41)
	case strings.HasPrefix(sanitized, "gpt-4o"):
		return tokenizer.ForModel(tokenizer.GPT4o)
	case strings.HasPrefix(sanitized, "gpt-4"):
		return tokenizer.ForModel(tokenizer.GPT4)
	case strings.HasPrefix(sanitized, "gpt-3.5"), strings.HasPrefix(sanitized, "gpt-3"):
		return tokenizer.ForModel(tokenizer.GPT35Turbo)
	default:
		return tokenizer.Get(tokenizer.Cl100kBase)
	}
}

func countCodexInputTokens(enc tokenizer.Codec, body []byte) (int64, error) {
	if enc == nil {
		return 0, fmt.Errorf("encoder is nil")
	}
	if len(body) == 0 {
		return 0, nil
	}

	root := gjson.ParseBytes(body)
	var segments []string

	if inst := strings.TrimSpace(root.Get("instructions").String()); inst != "" {
		segments = append(segments, inst)
	}

	inputItems := root.Get("input")
	if inputItems.IsArray() {
		arr := inputItems.Array()
		for i := range arr {
			item := arr[i]
			switch item.Get("type").String() {
			case "message":
				content := item.Get("content")
				if content.IsArray() {
					parts := content.Array()
					for j := range parts {
						part := parts[j]
						if text := strings.TrimSpace(part.Get("text").String()); text != "" {
							segments = append(segments, text)
						}
					}
				}
			case "function_call":
				if name := strings.TrimSpace(item.Get("name").String()); name != "" {
					segments = append(segments, name)
				}
				if args := strings.TrimSpace(item.Get("arguments").String()); args != "" {
					segments = append(segments, args)
				}
			case "function_call_output":
				if out := strings.TrimSpace(item.Get("output").String()); out != "" {
					segments = append(segments, out)
				}
			default:
				if text := strings.TrimSpace(item.Get("text").String()); text != "" {
					segments = append(segments, text)
				}
			}
		}
	}

	tools := root.Get("tools")
	if tools.IsArray() {
		tarr := tools.Array()
		for i := range tarr {
			tool := tarr[i]
			if name := strings.TrimSpace(tool.Get("name").String()); name != "" {
				segments = append(segments, name)
			}
			if desc := strings.TrimSpace(tool.Get("description").String()); desc != "" {
				segments = append(segments, desc)
			}
			if params := tool.Get("parameters"); params.Exists() {
				val := params.Raw
				if params.Type == gjson.String {
					val = params.String()
				}
				if trimmed := strings.TrimSpace(val); trimmed != "" {
					segments = append(segments, trimmed)
				}
			}
		}
	}

	textFormat := root.Get("text.format")
	if textFormat.Exists() {
		if name := strings.TrimSpace(textFormat.Get("name").String()); name != "" {
			segments = append(segments, name)
		}
		if schema := textFormat.Get("schema"); schema.Exists() {
			val := schema.Raw
			if schema.Type == gjson.String {
				val = schema.String()
			}
			if trimmed := strings.TrimSpace(val); trimmed != "" {
				segments = append(segments, trimmed)
			}
		}
	}

	text := strings.Join(segments, "\n")
	if text == "" {
		return 0, nil
	}

	count, err := enc.Count(text)
	if err != nil {
		return 0, err
	}
	return int64(count), nil
}

func codexCreds(a *cliproxyauth.Auth) (apiKey, baseURL string) {
	if a == nil {
		return "", ""
	}
	if a.Attributes != nil {
		apiKey = a.Attributes["api_key"]
		baseURL = a.Attributes["base_url"]
	}
	if apiKey == "" && a.Metadata != nil {
		if v, ok := a.Metadata["access_token"].(string); ok {
			apiKey = v
		}
	}
	return
}