package executor

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

	"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"
	"github.com/tidwall/gjson"
	"github.com/tidwall/sjson"
)

// GeminiExecutorRefactored is a stateless executor for the official Gemini API.
type GeminiExecutorRefactored struct {
	cfg  *config.Config
	base *BaseExecutor
}

// NewGeminiExecutorRefactored creates a new Gemini executor instance.
func NewGeminiExecutorRefactored(cfg *config.Config) *GeminiExecutorRefactored {
	provider := &GeminiProvider{}
	return &GeminiExecutorRefactored{
		cfg:  cfg,
		base: NewBaseExecutor(cfg, provider),
	}
}

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

// PrepareRequest injects Gemini credentials into the outgoing HTTP request.
func (e *GeminiExecutorRefactored) PrepareRequest(req *http.Request, auth *cliproxyauth.Auth) error {
	if req == nil {
		return nil
	}
	apiKey, bearer := geminiCreds(auth)
	if apiKey != "" {
		req.Header.Set("x-goog-api-key", apiKey)
		req.Header.Del("Authorization")
	} else if bearer != "" {
		req.Header.Set("Authorization", "Bearer "+bearer)
		req.Header.Del("x-goog-api-key")
	}
	applyGeminiHeadersRefactored(req, auth)
	return nil
}

// HttpRequest injects Gemini credentials into the request and executes it.
func (e *GeminiExecutorRefactored) HttpRequest(ctx context.Context, auth *cliproxyauth.Auth, req *http.Request) (*http.Response, error) {
	if req == nil {
		return nil, fmt.Errorf("gemini 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 Gemini API.
func (e *GeminiExecutorRefactored) Execute(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (resp cliproxyexecutor.Response, err error) {
	if opts.Alt == "responses/compact" {
		return resp, statusErr{code: http.StatusNotImplemented, msg: "/responses/compact not supported"}
	}

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

// ExecuteStream performs a streaming request to the Gemini API.
func (e *GeminiExecutorRefactored) 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.StatusNotImplemented, msg: "/responses/compact not supported"}
	}

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

// CountTokens counts tokens for the given request using the Gemini API.
func (e *GeminiExecutorRefactored) CountTokens(ctx context.Context, auth *cliproxyauth.Auth, req cliproxyexecutor.Request, opts cliproxyexecutor.Options) (cliproxyexecutor.Response, error) {
	baseModel := thinking.ParseSuffix(req.Model).ModelName

	apiKey, bearer := geminiCreds(auth)

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

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

	translatedReq = fixGeminiImageAspectRatio(baseModel, translatedReq)
	respCtx := context.WithValue(ctx, "alt", opts.Alt)
	translatedReq, _ = sjson.DeleteBytes(translatedReq, "tools")
	translatedReq, _ = sjson.DeleteBytes(translatedReq, "generationConfig")
	translatedReq, _ = sjson.DeleteBytes(translatedReq, "safetySettings")
	translatedReq, _ = sjson.SetBytes(translatedReq, "model", baseModel)

	baseURL := resolveGeminiBaseURL(auth)
	url := fmt.Sprintf("%s/%s/models/%s:%s", baseURL, glAPIVersion, baseModel, "countTokens")

	httpReq, err := http.NewRequestWithContext(ctx, http.MethodPost, url, strings.NewReader(string(translatedReq)))
	if err != nil {
		return cliproxyexecutor.Response{}, err
	}
	httpReq.Header.Set("Content-Type", "application/json")
	if apiKey != "" {
		httpReq.Header.Set("x-goog-api-key", apiKey)
	} else {
		httpReq.Header.Set("Authorization", "Bearer "+bearer)
	}
	applyGeminiHeadersRefactored(httpReq, auth)

	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:      translatedReq,
		Provider:  e.Identifier(),
		AuthID:    authID,
		AuthLabel: authLabel,
		AuthType:  authType,
		AuthValue: authValue,
	})

	httpClient := newProxyAwareHTTPClient(ctx, e.cfg, auth, 0)
	resp, err := httpClient.Do(httpReq)
	if err != nil {
		recordAPIResponseError(ctx, e.cfg, err)
		return cliproxyexecutor.Response{}, err
	}
	defer resp.Body.Close()
	recordAPIResponseMetadata(ctx, e.cfg, resp.StatusCode, resp.Header.Clone())

	data, err := io.ReadAll(resp.Body)
	if err != nil {
		recordAPIResponseError(ctx, e.cfg, err)
		return cliproxyexecutor.Response{}, err
	}
	appendAPIResponseChunk(ctx, e.cfg, data)
	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
		logWithRequestID(ctx).Debugf("request error, error status: %d, error message: %s", resp.StatusCode, summarizeErrorBody(resp.Header.Get("Content-Type"), data))
		return cliproxyexecutor.Response{}, statusErr{code: resp.StatusCode, msg: string(data)}
	}

	count := gjson.GetBytes(data, "totalTokens").Int()
	translated := sdktranslator.TranslateTokenCount(respCtx, to, from, count, data)
	return cliproxyexecutor.Response{Payload: []byte(translated), Headers: resp.Header.Clone()}, nil
}

// Refresh refreshes the authentication credentials (no-op for Gemini API key).
func (e *GeminiExecutorRefactored) Refresh(_ context.Context, auth *cliproxyauth.Auth) (*cliproxyauth.Auth, error) {
	return auth, nil
}

func geminiCreds(a *cliproxyauth.Auth) (apiKey, bearer string) {
	if a == nil {
		return "", ""
	}
	if a.Attributes != nil {
		if v := a.Attributes["api_key"]; v != "" {
			apiKey = v
		}
	}
	if a.Metadata != nil {
		// GeminiTokenStorage.Token is a map that may contain access_token
		if v, ok := a.Metadata["access_token"].(string); ok && v != "" {
			bearer = v
		}
		if token, ok := a.Metadata["token"].(map[string]any); ok && token != nil {
			if v, ok2 := token["access_token"].(string); ok2 && v != "" {
				bearer = v
			}
		}
	}
	return
}

func resolveGeminiBaseURL(auth *cliproxyauth.Auth) string {
	base := glEndpoint
	if auth != nil && auth.Attributes != nil {
		if custom := strings.TrimSpace(auth.Attributes["base_url"]); custom != "" {
			base = strings.TrimRight(custom, "/")
		}
	}
	if base == "" {
		return glEndpoint
	}
	return base
}

func applyGeminiHeadersRefactored(req *http.Request, auth *cliproxyauth.Auth) {
	var attrs map[string]string
	if auth != nil {
		attrs = auth.Attributes
	}
	util.ApplyCustomHeadersFromAttrs(req, attrs)
}