package main

import (
	"bufio"
	"bytes"
	"context"
	"crypto/sha256"
	"crypto/tls"
	"encoding/base64"
	"encoding/binary"
	"encoding/hex"
	"encoding/json"
	"errors"
	"flag"
	"fmt"
	"hash/crc32"
	"io"
	"net/http"
	"net/url"
	"os"
	"regexp"
	"sort"
	"strings"
	"sync"
	"time"

	"github.com/easyai/easyai-ai-gateway/apps/api/internal/acceptanceworkload"
)

const (
	runHeader      = "X-EasyAI-Acceptance-Run"
	tokenHeader    = "X-EasyAI-Acceptance-Token"
	upstreamHeader = "X-EasyAI-Acceptance-Upstream"
)

var reportURLPattern = regexp.MustCompile(`(?i)(?:https?|postgres(?:ql)?):\/\/[^\s"'<>]+`)

type options struct {
	gateways       []string
	gatewayTLSName string
	emulatorURL    string
	apiKey         string
	runID          string
	runToken       string
	geminiModel    string
	videoModel     string
	profile        string
	reportPath     string
	realImageURLs  []string
	timeout        time.Duration
}

type report struct {
	RunID      string        `json:"runId"`
	Profile    string        `json:"profile"`
	StartedAt  time.Time     `json:"startedAt"`
	FinishedAt time.Time     `json:"finishedAt"`
	Passed     bool          `json:"passed"`
	Phases     []phaseReport `json:"phases"`
	Failure    string        `json:"failure,omitempty"`
	SecretSafe bool          `json:"secretSafe"`
}

type phaseReport struct {
	Name                  string  `json:"name"`
	Requests              int     `json:"requests"`
	Completed             int     `json:"completed"`
	Failed                int     `json:"failed"`
	DurationMS            int64   `json:"durationMs"`
	SubmissionDurationMS  int64   `json:"submissionDurationMs,omitempty"`
	P50MS                 float64 `json:"p50Ms"`
	P95MS                 float64 `json:"p95Ms"`
	P99MS                 float64 `json:"p99Ms"`
	DecodedOutputBytes    int64   `json:"decodedOutputBytes,omitempty"`
	OutputSHA256          string  `json:"outputSha256,omitempty"`
	UniqueTaskIDs         int     `json:"uniqueTaskIds,omitempty"`
	UniqueImageCombos     int     `json:"uniqueImageCombinations,omitempty"`
	ForcedConversionTasks int     `json:"forcedConversionTasks,omitempty"`
}

type phaseResult struct {
	report    phaseReport
	latencies []time.Duration
	err       error
}

func main() {
	opts, err := parseOptions()
	if err != nil {
		fmt.Fprintln(os.Stderr, "acceptance load configuration error:", err)
		os.Exit(2)
	}
	ctx, cancel := context.WithTimeout(context.Background(), opts.timeout)
	defer cancel()
	result := report{
		RunID: opts.runID, Profile: opts.profile, StartedAt: time.Now().UTC(), SecretSafe: true,
	}
	phaseResults, runErr := run(ctx, opts)
	for _, phase := range phaseResults {
		phase.report.P50MS = percentileMilliseconds(phase.latencies, 0.50)
		phase.report.P95MS = percentileMilliseconds(phase.latencies, 0.95)
		phase.report.P99MS = percentileMilliseconds(phase.latencies, 0.99)
		result.Phases = append(result.Phases, phase.report)
		if runErr == nil && phase.err != nil {
			runErr = phase.err
		}
	}
	result.FinishedAt = time.Now().UTC()
	result.Passed = runErr == nil
	if runErr != nil {
		result.Failure = redactError(runErr.Error(), opts)
	}
	payload, _ := json.MarshalIndent(result, "", "  ")
	fmt.Println(string(payload))
	if opts.reportPath != "" {
		if err := os.WriteFile(opts.reportPath, append(payload, '\n'), 0o600); err != nil {
			fmt.Fprintln(os.Stderr, "write acceptance report failed:", err)
			os.Exit(1)
		}
	}
	if runErr != nil {
		os.Exit(1)
	}
}

func parseOptions() (options, error) {
	var profile string
	var reportPath string
	var timeout time.Duration
	flag.StringVar(&profile, "profile", env("AI_GATEWAY_ACCEPTANCE_PROFILE", "simulated-all"), "simulated-all, Gemini profile, video profile, or real-canary")
	flag.StringVar(&reportPath, "report", env("AI_GATEWAY_ACCEPTANCE_REPORT", ""), "secret-safe JSON report path")
	flag.DurationVar(&timeout, "timeout", 45*time.Minute, "overall timeout")
	flag.Parse()
	opts := options{
		gateways:       splitCSV(os.Getenv("AI_GATEWAY_ACCEPTANCE_GATEWAYS")),
		gatewayTLSName: strings.TrimSpace(os.Getenv("AI_GATEWAY_ACCEPTANCE_GATEWAY_TLS_SERVER_NAME")),
		emulatorURL:    strings.TrimRight(strings.TrimSpace(os.Getenv("AI_GATEWAY_ACCEPTANCE_EMULATOR_URL")), "/"),
		apiKey:         strings.TrimSpace(os.Getenv("AI_GATEWAY_ACCEPTANCE_API_KEY")),
		runID:          strings.TrimSpace(os.Getenv("AI_GATEWAY_ACCEPTANCE_RUN_ID")),
		runToken:       strings.TrimSpace(os.Getenv("AI_GATEWAY_ACCEPTANCE_RUN_TOKEN")),
		geminiModel:    strings.TrimSpace(os.Getenv("AI_GATEWAY_ACCEPTANCE_GEMINI_MODEL")),
		videoModel:     strings.TrimSpace(os.Getenv("AI_GATEWAY_ACCEPTANCE_VIDEO_MODEL")),
		profile:        strings.ToLower(strings.TrimSpace(profile)),
		reportPath:     strings.TrimSpace(reportPath),
		realImageURLs:  splitCSV(os.Getenv("AI_GATEWAY_ACCEPTANCE_REAL_IMAGE_URLS")),
		timeout:        timeout,
	}
	if len(opts.gateways) != 2 {
		return options{}, errors.New("AI_GATEWAY_ACCEPTANCE_GATEWAYS must contain exactly two API base URLs")
	}
	for index := range opts.gateways {
		opts.gateways[index] = strings.TrimRight(opts.gateways[index], "/")
		if _, err := url.ParseRequestURI(opts.gateways[index]); err != nil {
			return options{}, fmt.Errorf("gateway %d URL is invalid", index+1)
		}
	}
	if opts.gatewayTLSName != "" &&
		(strings.ContainsAny(opts.gatewayTLSName, "/:@") || !strings.Contains(opts.gatewayTLSName, ".")) {
		return options{}, errors.New("AI_GATEWAY_ACCEPTANCE_GATEWAY_TLS_SERVER_NAME must be a DNS hostname")
	}
	if opts.apiKey == "" || opts.runID == "" || opts.runToken == "" {
		return options{}, errors.New("acceptance API key, Run ID, and Run Token environment variables are required")
	}
	if opts.geminiModel == "" || opts.videoModel == "" {
		return options{}, errors.New("Gemini and video model environment variables are required")
	}
	if opts.timeout <= 0 {
		return options{}, errors.New("timeout must be positive")
	}
	switch opts.profile {
	case "simulated-all", "gemini-baseline", "gemini-large", "gemini-peak", "video-throughput", "video-recovery":
		if opts.emulatorURL == "" {
			return options{}, errors.New("AI_GATEWAY_ACCEPTANCE_EMULATOR_URL is required for simulated profiles")
		}
	case "real-canary":
		if len(opts.realImageURLs) < 3 {
			return options{}, errors.New("real-canary requires at least three public AI_GATEWAY_ACCEPTANCE_REAL_IMAGE_URLS")
		}
	default:
		return options{}, fmt.Errorf("unsupported profile %q", opts.profile)
	}
	return opts, nil
}

func run(ctx context.Context, opts options) ([]phaseResult, error) {
	var tlsConfig *tls.Config
	if opts.gatewayTLSName != "" {
		tlsConfig = &tls.Config{
			MinVersion: tls.VersionTLS12,
			ServerName: opts.gatewayTLSName,
		}
	}
	client := &http.Client{
		Timeout: opts.timeout,
		Transport: &http.Transport{
			MaxIdleConns:        2048,
			MaxIdleConnsPerHost: 1024,
			MaxConnsPerHost:     1024,
			TLSClientConfig:     tlsConfig,
		},
	}
	results := make([]phaseResult, 0, 5)
	runPhase := func(name string) error {
		var result phaseResult
		if profile, ok := acceptanceworkload.GeminiProfileByName(name); ok {
			result = runGemini(ctx, client, opts, name, profile.Requests, profile.InputBytes, profile.OutputBytes, false)
		} else {
			switch name {
			case "video-throughput":
				result = runVideo(ctx, client, opts, name, 1200, false, opts.emulatorFixtureURLs(), false)
			case "video-recovery":
				result = runVideo(ctx, client, opts, name, 96, true, opts.emulatorFixtureURLs(), false)
			case "real-gemini-canary":
				result = runGemini(ctx, client, opts, name, 1, 256<<10, 0, true)
			case "real-video-canary":
				result = runVideo(ctx, client, opts, name, 1, false, opts.realImageURLs, true)
			default:
				return fmt.Errorf("unknown phase %q", name)
			}
		}
		results = append(results, result)
		return result.err
	}
	phases := []string{opts.profile}
	if opts.profile == "simulated-all" {
		phases = []string{"gemini-baseline", "gemini-large", "gemini-peak", "video-throughput", "video-recovery"}
	} else if opts.profile == "real-canary" {
		phases = []string{"real-gemini-canary", "real-video-canary"}
	}
	for _, phase := range phases {
		if err := runPhase(phase); err != nil {
			return results, err
		}
	}
	return results, nil
}

func runGemini(
	ctx context.Context,
	client *http.Client,
	opts options,
	name string,
	requestCount int,
	inputBytes int,
	expectedOutputBytes int,
	realUpstream bool,
) phaseResult {
	startedAt := time.Now()
	input := paddedPNG(inputBytes)
	requestBody, _ := json.Marshal(map[string]any{
		"contents": []any{map[string]any{
			"role": "user",
			"parts": []any{
				map[string]any{"text": "将参考图编辑为蓝色赛博朋克风格，保留主体结构"},
				map[string]any{"inlineData": map[string]any{
					"mimeType": "image/png",
					"data":     base64.StdEncoding.EncodeToString(input),
				}},
			},
		}},
		"generationConfig": map[string]any{"responseModalities": []any{"IMAGE"}},
	})
	expectedHash := ""
	if expectedOutputBytes > 0 {
		sum := sha256.Sum256(paddedPNG(expectedOutputBytes))
		expectedHash = hex.EncodeToString(sum[:])
	}
	latencies := make([]time.Duration, requestCount)
	var decodedBytes int64
	var completed int
	var failures int
	var firstErr error
	var mu sync.Mutex
	slots := make(chan struct{}, requestCount)
	var wg sync.WaitGroup
	for index := 0; index < requestCount; index++ {
		index := index
		wg.Add(1)
		go func() {
			defer wg.Done()
			select {
			case slots <- struct{}{}:
			case <-ctx.Done():
				return
			}
			defer func() { <-slots }()
			requestStarted := time.Now()
			endpoint := opts.gateways[index%len(opts.gateways)] + "/v1beta/models/" + url.PathEscape(opts.geminiModel) + ":generateContent"
			req, err := http.NewRequestWithContext(ctx, http.MethodPost, endpoint, bytes.NewReader(requestBody))
			if err == nil {
				opts.setHeaders(req, realUpstream)
				req.Header.Set("Content-Type", "application/json")
				var response *http.Response
				response, err = client.Do(req)
				if err == nil {
					if response.StatusCode != http.StatusOK {
						err = responseStatusError(response)
					} else {
						var size int64
						var outputHash string
						size, outputHash, err = streamGeminiImageHash(response.Body)
						_ = response.Body.Close()
						if err == nil && expectedOutputBytes > 0 && (size != int64(expectedOutputBytes) || outputHash != expectedHash) {
							err = fmt.Errorf("Gemini output mismatch: bytes=%d hash=%s", size, outputHash)
						}
						if err == nil {
							mu.Lock()
							decodedBytes += size
							if expectedHash == "" {
								expectedHash = outputHash
							}
							mu.Unlock()
						}
					}
				}
			}
			latency := time.Since(requestStarted)
			mu.Lock()
			latencies[index] = latency
			if err != nil {
				failures++
				if firstErr == nil {
					firstErr = err
				}
			} else {
				completed++
			}
			mu.Unlock()
		}()
	}
	wg.Wait()
	elapsed := time.Since(startedAt)
	result := phaseReport{
		Name: name, Requests: requestCount, Completed: completed, Failed: failures,
		DurationMS: elapsed.Milliseconds(), DecodedOutputBytes: decodedBytes, OutputSHA256: expectedHash,
	}
	if firstErr == nil && name == "gemini-baseline" && elapsed > 8*time.Minute {
		firstErr = fmt.Errorf("Gemini baseline exceeded 8 minutes: %s", elapsed)
	}
	if firstErr == nil && completed != requestCount {
		firstErr = fmt.Errorf("Gemini completed %d of %d requests", completed, requestCount)
	}
	return phaseResult{report: result, latencies: latencies, err: firstErr}
}

func runVideo(
	ctx context.Context,
	client *http.Client,
	opts options,
	name string,
	requestCount int,
	longRun bool,
	imageURLs []string,
	realUpstream bool,
) phaseResult {
	startedAt := time.Now()
	combinationCount := 128
	if realUpstream {
		combinationCount = 1
	}
	combinations := videoCombinations(imageURLs, combinationCount)
	var taskIDs = make([]string, requestCount)
	latencies := make([]time.Duration, requestCount)
	startedTasks := make([]time.Time, requestCount)
	var completed int
	var failures int
	var forcedConversions int
	var firstErr error
	var mu sync.Mutex
	var wg sync.WaitGroup
	submitStartedAt := time.Now()
	for index := 0; index < requestCount; index++ {
		index := index
		wg.Add(1)
		go func() {
			defer wg.Done()
			requestStarted := time.Now()
			startedTasks[index] = requestStarted
			imageCount := acceptanceworkload.VideoImageCount(index)
			combo := append([]string(nil), combinations[index%len(combinations)]...)
			if len(combo) > imageCount {
				combo = combo[:imageCount]
			}
			if !realUpstream && index%4 == 0 {
				combo[0] = imageURLs[12+(index/4)%4]
			}
			content := make([]any, 0, len(combo)+1)
			prompt := "多参考图生成连续运镜视频，保持人物、服装和场景一致"
			if longRun {
				prompt += " acceptance-long-recovery"
			}
			if !realUpstream && index%4 == 0 {
				prompt += " acceptance-force-conversion"
			}
			content = append(content, map[string]any{"type": "text", "text": prompt})
			for imageIndex, imageURL := range combo {
				role := "reference_image"
				if index%5 == 0 && imageIndex == 0 {
					role = "first_frame"
				}
				if index%5 == 0 && len(combo) > 3 && imageIndex == len(combo)-1 {
					role = "last_frame"
				}
				content = append(content, map[string]any{
					"type": "image_url", "role": role,
					"image_url": map[string]any{"url": imageURL},
				})
			}
			body, _ := json.Marshal(map[string]any{
				"model": opts.videoModel, "modelType": "omni_video", "content": content, "seed": index + 1,
				"duration": 5, "ratio": "16:9", "resolution": "720p",
			})
			endpoint := opts.gateways[index%len(opts.gateways)] + "/api/v1/videos/generations"
			req, err := http.NewRequestWithContext(ctx, http.MethodPost, endpoint, bytes.NewReader(body))
			if err == nil {
				opts.setHeaders(req, realUpstream)
				req.Header.Set("Content-Type", "application/json")
				req.Header.Set("X-Async", "true")
				var response *http.Response
				response, err = client.Do(req)
				if err == nil {
					if response.StatusCode != http.StatusAccepted {
						err = responseStatusError(response)
					} else {
						var accepted struct {
							TaskID string `json:"taskId"`
						}
						err = json.NewDecoder(io.LimitReader(response.Body, 1<<20)).Decode(&accepted)
						_ = response.Body.Close()
						taskIDs[index] = strings.TrimSpace(accepted.TaskID)
						if err == nil && taskIDs[index] == "" {
							err = errors.New("video acceptance response did not include taskId")
						}
					}
				}
			}
			mu.Lock()
			latencies[index] = time.Since(requestStarted)
			if !realUpstream && index%4 == 0 {
				forcedConversions++
			}
			if err != nil {
				failures++
				if firstErr == nil {
					firstErr = err
				}
			}
			mu.Unlock()
		}()
	}
	wg.Wait()
	submissionDuration := time.Since(submitStartedAt)
	if firstErr == nil && name == "video-throughput" && submissionDuration > 10*time.Second {
		firstErr = fmt.Errorf("1200 video submissions exceeded 10 seconds: %s", submissionDuration)
	}
	uniqueTaskIDs := map[string]struct{}{}
	for _, taskID := range taskIDs {
		if taskID != "" {
			uniqueTaskIDs[taskID] = struct{}{}
		}
	}
	if firstErr == nil && len(uniqueTaskIDs) != requestCount {
		firstErr = fmt.Errorf("video task IDs are not unique: unique=%d requests=%d", len(uniqueTaskIDs), requestCount)
	}
	pollSlots := make(chan struct{}, 256)
	for index, taskID := range taskIDs {
		if taskID == "" {
			continue
		}
		index, taskID := index, taskID
		wg.Add(1)
		go func() {
			defer wg.Done()
			select {
			case pollSlots <- struct{}{}:
			case <-ctx.Done():
				return
			}
			defer func() { <-pollSlots }()
			err := pollVideoTask(ctx, client, opts, taskID, index, realUpstream)
			mu.Lock()
			latencies[index] = time.Since(startedTasks[index])
			if err != nil {
				failures++
				if firstErr == nil {
					firstErr = err
				}
			} else {
				completed++
			}
			mu.Unlock()
		}()
	}
	wg.Wait()
	comboSet := map[string]struct{}{}
	for _, combo := range combinations {
		comboSet[strings.Join(combo, "\x00")] = struct{}{}
	}
	elapsed := time.Since(startedAt)
	result := phaseReport{
		Name: name, Requests: requestCount, Completed: completed, Failed: failures,
		DurationMS: elapsed.Milliseconds(), SubmissionDurationMS: submissionDuration.Milliseconds(),
		UniqueTaskIDs: len(uniqueTaskIDs), UniqueImageCombos: len(comboSet),
		ForcedConversionTasks: forcedConversions,
	}
	if firstErr == nil && completed != requestCount {
		firstErr = fmt.Errorf("video completed %d of %d tasks", completed, requestCount)
	}
	return phaseResult{report: result, latencies: latencies, err: firstErr}
}

func pollVideoTask(ctx context.Context, client *http.Client, opts options, taskID string, index int, realUpstream bool) error {
	ticker := time.NewTicker(time.Second)
	defer ticker.Stop()
	for {
		endpoint := opts.gateways[index%len(opts.gateways)] + "/api/v1/ai/result/" + url.PathEscape(taskID)
		req, err := http.NewRequestWithContext(ctx, http.MethodGet, endpoint, nil)
		if err != nil {
			return err
		}
		opts.setHeaders(req, realUpstream)
		response, err := client.Do(req)
		if err == nil {
			if response.StatusCode != http.StatusOK {
				err = responseStatusError(response)
			} else {
				var payload map[string]any
				err = json.NewDecoder(io.LimitReader(response.Body, 2<<20)).Decode(&payload)
				_ = response.Body.Close()
				status := strings.ToLower(strings.TrimSpace(fmt.Sprint(payload["status"])))
				switch status {
				case "succeeded", "success":
					mediaURL := findMediaURL(payload)
					if mediaURL == "" {
						return fmt.Errorf("video task %s succeeded without a media URL", taskID)
					}
					return validateVideoAsset(ctx, http.DefaultClient, mediaURL)
				case "failed", "cancelled", "canceled":
					return fmt.Errorf("video task %s finished with status %s", taskID, status)
				}
			}
		}
		if err != nil {
			return err
		}
		select {
		case <-ctx.Done():
			return ctx.Err()
		case <-ticker.C:
		}
	}
}

func findMediaURL(value any) string {
	switch typed := value.(type) {
	case map[string]any:
		for key, item := range typed {
			normalized := strings.ToLower(strings.TrimSpace(key))
			if (normalized == "url" || normalized == "video_url") && strings.HasPrefix(strings.TrimSpace(fmt.Sprint(item)), "http") {
				return strings.TrimSpace(fmt.Sprint(item))
			}
			if mediaURL := findMediaURL(item); mediaURL != "" {
				return mediaURL
			}
		}
	case []any:
		for _, item := range typed {
			if mediaURL := findMediaURL(item); mediaURL != "" {
				return mediaURL
			}
		}
	}
	return ""
}

func validateVideoAsset(ctx context.Context, client *http.Client, mediaURL string) error {
	request, err := http.NewRequestWithContext(ctx, http.MethodGet, mediaURL, nil)
	if err != nil {
		return err
	}
	response, err := client.Do(request)
	if err != nil {
		return fmt.Errorf("download final video: %w", err)
	}
	defer response.Body.Close()
	if response.StatusCode < 200 || response.StatusCode >= 300 {
		return fmt.Errorf("download final video: HTTP %d", response.StatusCode)
	}
	payload, err := io.ReadAll(io.LimitReader(response.Body, 64<<10))
	if err != nil {
		return fmt.Errorf("read final video: %w", err)
	}
	contentType := strings.ToLower(strings.TrimSpace(response.Header.Get("Content-Type")))
	hasMP4Header := len(payload) >= 12 && string(payload[4:8]) == "ftyp"
	if len(payload) < 12 || (!strings.HasPrefix(contentType, "video/") && !hasMP4Header) {
		return fmt.Errorf("final video asset is invalid: bytes=%d content_type=%q", len(payload), contentType)
	}
	return nil
}

func (o options) setHeaders(request *http.Request, realUpstream bool) {
	if o.gatewayTLSName != "" {
		request.Host = o.gatewayTLSName
	}
	request.Header.Set("Authorization", "Bearer "+o.apiKey)
	request.Header.Set(runHeader, o.runID)
	request.Header.Set(tokenHeader, o.runToken)
	if realUpstream {
		request.Header.Set(upstreamHeader, "real")
	}
}

func (o options) emulatorFixtureURLs() []string {
	out := make([]string, 0, 16)
	for index := 0; index < 4; index++ {
		out = append(out, fmt.Sprintf("%s/fixtures/image-%02d.png", o.emulatorURL, index))
	}
	for index := 4; index < 8; index++ {
		out = append(out, fmt.Sprintf("%s/fixtures/image-%02d.jpg", o.emulatorURL, index))
	}
	for index := 8; index < 12; index++ {
		out = append(out, fmt.Sprintf("%s/fixtures/image-%02d.webp", o.emulatorURL, index))
	}
	for index := 12; index < 16; index++ {
		out = append(out, fmt.Sprintf("%s/fixtures/image-%02d-4k.jpg", o.emulatorURL, index))
	}
	return out
}

func videoCombinations(images []string, count int) [][]string {
	if len(images) < 3 {
		return nil
	}
	if len(images) < 9 {
		return [][]string{append([]string(nil), images[:3]...)}
	}
	out := make([][]string, 0, count)
	seen := map[string]struct{}{}
	for seed := 0; len(out) < count; seed++ {
		imageCount := acceptanceworkload.VideoImageCount(seed)
		combo := make([]string, 0, imageCount)
		used := map[int]struct{}{}
		state := uint64(seed + 1)
		for len(combo) < imageCount {
			state = state*6364136223846793005 + 1442695040888963407
			index := int((state >> 32) % uint64(len(images)))
			if _, exists := used[index]; exists {
				continue
			}
			used[index] = struct{}{}
			combo = append(combo, images[index])
		}
		signature := strings.Join(combo, "\x00")
		if _, exists := seen[signature]; exists {
			continue
		}
		seen[signature] = struct{}{}
		out = append(out, combo)
	}
	return out
}

func streamGeminiImageHash(reader io.Reader) (int64, string, error) {
	buffered := bufio.NewReaderSize(reader, 64<<10)
	if err := scanUntil(buffered, []byte(`"inlineData"`), 256<<20); err != nil {
		return 0, "", err
	}
	if err := scanUntil(buffered, []byte(`"data"`), 1<<20); err != nil {
		return 0, "", err
	}
	for {
		item, err := buffered.ReadByte()
		if err != nil {
			return 0, "", err
		}
		if item == ':' {
			break
		}
	}
	for {
		item, err := buffered.ReadByte()
		if err != nil {
			return 0, "", err
		}
		if item == '"' {
			break
		}
		if item != ' ' && item != '\t' && item != '\r' && item != '\n' {
			return 0, "", errors.New("Gemini inlineData.data is not a JSON string")
		}
	}
	jsonString := &base64JSONStringReader{reader: buffered}
	digest := sha256.New()
	decodedBytes, err := io.Copy(digest, base64.NewDecoder(base64.StdEncoding, jsonString))
	if err != nil {
		return 0, "", fmt.Errorf("decode Gemini Base64 output: %w", err)
	}
	if decodedBytes == 0 {
		return 0, "", errors.New("Gemini Base64 output is empty")
	}
	return decodedBytes, hex.EncodeToString(digest.Sum(nil)), nil
}

type base64JSONStringReader struct {
	reader *bufio.Reader
	done   bool
}

func (r *base64JSONStringReader) Read(payload []byte) (int, error) {
	if r.done {
		return 0, io.EOF
	}
	written := 0
	for written < len(payload) {
		item, err := r.reader.ReadByte()
		if err != nil {
			return written, err
		}
		if item == '"' {
			r.done = true
			if written == 0 {
				return 0, io.EOF
			}
			return written, nil
		}
		if item == '\\' {
			return written, errors.New("escaped Base64 JSON strings are not supported")
		}
		payload[written] = item
		written++
	}
	return written, nil
}

func scanUntil(reader *bufio.Reader, target []byte, limit int64) error {
	matched := 0
	for read := int64(0); read < limit; read++ {
		item, err := reader.ReadByte()
		if err != nil {
			return err
		}
		if item == target[matched] {
			matched++
			if matched == len(target) {
				return nil
			}
			continue
		}
		if item == target[0] {
			matched = 1
		} else {
			matched = 0
		}
	}
	return errors.New("Gemini inlineData output was not found")
}

func responseStatusError(response *http.Response) error {
	defer response.Body.Close()
	payload, _ := io.ReadAll(io.LimitReader(response.Body, 512))
	return fmt.Errorf("HTTP %d: %s", response.StatusCode, strings.TrimSpace(string(payload)))
}

func percentileMilliseconds(values []time.Duration, quantile float64) float64 {
	filtered := make([]time.Duration, 0, len(values))
	for _, value := range values {
		if value > 0 {
			filtered = append(filtered, value)
		}
	}
	if len(filtered) == 0 {
		return 0
	}
	sort.Slice(filtered, func(i, j int) bool { return filtered[i] < filtered[j] })
	index := int(float64(len(filtered)-1) * quantile)
	return float64(filtered[index].Microseconds()) / 1000
}

func paddedPNG(size int) []byte {
	base, _ := base64.StdEncoding.DecodeString("iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNk+A8AAQUBAScY42YAAAAASUVORK5CYII=")
	if size <= len(base) {
		return base
	}
	iendOffset := len(base) - 12
	paddingLength := size - len(base) - 12
	if paddingLength < 0 {
		paddingLength = 0
	}
	chunk := make([]byte, 12+paddingLength)
	binary.BigEndian.PutUint32(chunk[:4], uint32(paddingLength))
	copy(chunk[4:8], []byte("teST"))
	binary.BigEndian.PutUint32(chunk[8+paddingLength:], crc32.ChecksumIEEE(chunk[4:8+paddingLength]))
	out := make([]byte, 0, size)
	out = append(out, base[:iendOffset]...)
	out = append(out, chunk...)
	out = append(out, base[iendOffset:]...)
	return out
}

func redactError(message string, opts options) string {
	for _, secret := range []string{opts.apiKey, opts.runToken} {
		if secret != "" {
			message = strings.ReplaceAll(message, secret, "[REDACTED]")
		}
	}
	return reportURLPattern.ReplaceAllString(message, "[REDACTED_URL]")
}

func splitCSV(value string) []string {
	items := strings.Split(value, ",")
	out := make([]string, 0, len(items))
	for _, item := range items {
		if item = strings.TrimSpace(item); item != "" {
			out = append(out, item)
		}
	}
	return out
}

func env(name string, fallback string) string {
	if value := strings.TrimSpace(os.Getenv(name)); value != "" {
		return value
	}
	return fallback
}