package executor

import (
	"bytes"
	"context"
	"errors"
	"io"
	"net/http"
	"net/url"
	"strings"

	"github.com/router-for-me/CLIProxyAPI/v7/internal/runtime/executor/helps"
	"github.com/router-for-me/CLIProxyAPI/v7/internal/thinking"
	"github.com/router-for-me/CLIProxyAPI/v7/internal/util"
	cliproxyauth "github.com/router-for-me/CLIProxyAPI/v7/sdk/cliproxy/auth"
	cliproxyexecutor "github.com/router-for-me/CLIProxyAPI/v7/sdk/cliproxy/executor"
	sdktranslator "github.com/router-for-me/CLIProxyAPI/v7/sdk/translator"
	log "github.com/sirupsen/logrus"
	"github.com/tidwall/gjson"
)

// CountTokens counts tokens for the given request using the Antigravity API.
func (e *AntigravityExecutor) 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
	responseFormat := cliproxyexecutor.ResponseFormatOrSource(opts)
	to := sdktranslator.FromString("antigravity")
	respCtx := context.WithValue(ctx, "alt", opts.Alt)
	originalPayloadSource := req.Payload
	if len(opts.OriginalRequest) > 0 {
		originalPayloadSource = opts.OriginalRequest
	}
	originalPayloadSource, errValidate := validateAntigravityRequestSignatures(ctx, baseModel, from, originalPayloadSource)
	if errValidate != nil {
		return cliproxyexecutor.Response{}, errValidate
	}
	req.Payload = originalPayloadSource
	token, updatedAuth, errToken := e.ensureAccessToken(ctx, auth)
	if errToken != nil {
		return cliproxyexecutor.Response{}, errToken
	}
	if updatedAuth != nil {
		auth = updatedAuth
	}
	cliproxyauth.NotifyAccessTokenFingerprint(ctx, auth)
	if strings.TrimSpace(token) == "" {
		return cliproxyexecutor.Response{}, statusErr{code: http.StatusUnauthorized, msg: "missing access token"}
	}

	// Prepare payload once (doesn't depend on baseURL)
	payload := helps.TranslateRequestWithCodexMultiAgentV2(ctx, opts.Headers, e.cfg, from, to, baseModel, req.Payload, false)

	payload, err := helps.ApplyThinkingWithSourcePayload(payload, req.Payload, originalPayloadSource, req.Model, from.String(), to.String(), e.Identifier())
	if err != nil {
		return cliproxyexecutor.Response{}, err
	}
	payload = e.obfuscateSensitiveWords(payload)
	payload = sanitizeAntigravityGeminiRequestSignatures(baseModel, payload)
	preparedPayload, _, errReplay := prepareAntigravityGeminiReasoningReplayPayload(ctx, baseModel, req, opts, payload)
	if errReplay != nil {
		return cliproxyexecutor.Response{}, errReplay
	}
	payload = ensureAntigravityGeminiLeadingUserContent(baseModel, preparedPayload)

	payload = helps.DeleteJSONField(payload, "project")
	payload = helps.DeleteJSONField(payload, "model")
	payload = helps.DeleteJSONField(payload, "request.safetySettings")

	baseURLs := antigravityBaseURLFallbackOrder(auth)
	httpClient := newAntigravityHTTPClient(ctx, e.cfg, auth, 0)

	var authID, authLabel, authType, authValue string
	if auth != nil {
		authID = auth.ID
		authLabel = auth.Label
		authType, authValue = auth.AccountInfo()
	}

	var lastStatus int
	var lastBody []byte
	var lastErr error

	for idx, baseURL := range baseURLs {
		base := strings.TrimSuffix(baseURL, "/")
		if base == "" {
			base = buildBaseURL(auth)
		}

		var requestURL strings.Builder
		requestURL.WriteString(base)
		requestURL.WriteString(antigravityCountTokensPath)
		if opts.Alt != "" {
			requestURL.WriteString("?$alt=")
			requestURL.WriteString(url.QueryEscape(opts.Alt))
		}

		httpReq, errReq := http.NewRequestWithContext(ctx, http.MethodPost, requestURL.String(), bytes.NewReader(payload))
		if errReq != nil {
			return cliproxyexecutor.Response{}, errReq
		}
		// No httpReq.Close: keep the shared Antigravity connection pool usable.
		httpReq.Header.Set("Content-Type", "application/json")
		httpReq.Header.Set("Authorization", "Bearer "+token)
		httpReq.Header.Set("User-Agent", resolveUserAgent(auth))
		if host := resolveHost(base); host != "" {
			httpReq.Host = host
		}
		var attrs map[string]string
		if auth != nil {
			attrs = auth.Attributes
		}
		util.ApplyCustomHeadersFromAttrs(httpReq, attrs)

		helps.RecordAPIRequest(ctx, e.cfg, helps.UpstreamRequestLog{
			URL:       requestURL.String(),
			Method:    http.MethodPost,
			Headers:   httpReq.Header.Clone(),
			Body:      payload,
			Provider:  e.Identifier(),
			AuthID:    authID,
			AuthLabel: authLabel,
			AuthType:  authType,
			AuthValue: authValue,
		})

		httpResp, errDo := httpClient.Do(httpReq)
		if errDo != nil {
			helps.RecordAPIResponseError(ctx, e.cfg, errDo)
			if errors.Is(errDo, context.Canceled) || errors.Is(errDo, context.DeadlineExceeded) {
				return cliproxyexecutor.Response{}, errDo
			}
			lastStatus = 0
			lastBody = nil
			lastErr = errDo
			if idx+1 < len(baseURLs) {
				log.Debugf("antigravity executor: request error on base url %s, retrying with fallback base url: %s", baseURL, baseURLs[idx+1])
				continue
			}
			return cliproxyexecutor.Response{}, errDo
		}

		helps.RecordAPIResponseMetadata(ctx, e.cfg, httpResp.StatusCode, httpResp.Header.Clone())
		bodyBytes, errRead := io.ReadAll(httpResp.Body)
		if errClose := httpResp.Body.Close(); errClose != nil {
			log.Errorf("antigravity executor: close response body error: %v", errClose)
		}
		if errRead != nil {
			helps.RecordAPIResponseError(ctx, e.cfg, errRead)
			return cliproxyexecutor.Response{}, errRead
		}
		helps.AppendAPIResponseChunk(ctx, e.cfg, bodyBytes)

		if httpResp.StatusCode >= http.StatusOK && httpResp.StatusCode < http.StatusMultipleChoices {
			count := gjson.GetBytes(bodyBytes, "totalTokens").Int()
			translated := sdktranslator.TranslateTokenCount(respCtx, to, responseFormat, count, bodyBytes)
			return cliproxyexecutor.Response{Payload: translated, Headers: httpResp.Header.Clone()}, nil
		}

		lastStatus = httpResp.StatusCode
		lastBody = append([]byte(nil), bodyBytes...)
		lastErr = nil
		if httpResp.StatusCode == http.StatusTooManyRequests && idx+1 < len(baseURLs) {
			log.Debugf("antigravity executor: rate limited on base url %s, retrying with fallback base url: %s", baseURL, baseURLs[idx+1])
			continue
		}
		sErr := statusErr{code: httpResp.StatusCode, msg: string(bodyBytes)}
		if httpResp.StatusCode == http.StatusTooManyRequests {
			if retryAfter, parseErr := helps.ParseRetryDelay(bodyBytes); parseErr == nil && retryAfter != nil {
				sErr.retryAfter = retryAfter
			}
		}
		return cliproxyexecutor.Response{}, sErr
	}

	switch {
	case lastStatus != 0:
		sErr := statusErr{code: lastStatus, msg: string(lastBody)}
		if lastStatus == http.StatusTooManyRequests {
			if retryAfter, parseErr := helps.ParseRetryDelay(lastBody); parseErr == nil && retryAfter != nil {
				sErr.retryAfter = retryAfter
			}
		}
		return cliproxyexecutor.Response{}, sErr
	case lastErr != nil:
		return cliproxyexecutor.Response{}, lastErr
	default:
		return cliproxyexecutor.Response{}, statusErr{code: http.StatusServiceUnavailable, msg: "antigravity executor: no base url available"}
	}
}