package jobs

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"math"
	"net/url"
	"strings"
	"time"

	"git.nianxx.cn/wangxuming/NianAIGC/backend/internal/prompt"
	"git.nianxx.cn/wangxuming/NianAIGC/backend/internal/providers"
)

type ProviderRegistry map[string]providers.Adapter

type ProviderProcessor struct {
	Providers ProviderRegistry
	Store     Store
}

func (p ProviderProcessor) Advance(ctx context.Context, job Job) (Job, error) {
	// A persisted terminal provider result is the recovery checkpoint. Replaying
	// it must run downstream idempotent finalizers, never submit/query again.
	if job.Status.Terminal() {
		return job, nil
	}
	adapter := p.Providers[job.Provider]
	if adapter == nil {
		return Job{}, fmt.Errorf("generation provider %q is unavailable", job.Provider)
	}
	var request providers.Request
	if err := json.Unmarshal(job.RequestPayload, &request); err != nil {
		return Job{}, errors.New("invalid provider request payload")
	}
	var result providers.Result
	var err error
	expectedStatus := job.Status
	if job.ProviderTaskID == "" {
		if job.ProviderDispatchStartedAt != nil {
			failed := StatusFailed
			failure := &JobError{Message: "provider submission outcome is unknown; refusing duplicate submission", Retryable: false}
			if p.Store == nil {
				job.Status, job.Error = failed, failure
				return job, nil
			}
			return p.Store.UpdateJob(ctx, job.ID, workerPatch(job, Patch{Status: &failed, Error: failure}))
		}
		if p.Store != nil {
			started := time.Now().UTC()
			prepared, persistErr := p.Store.UpdateJob(ctx, job.ID, workerPatch(job, Patch{ProviderDispatchStartedAt: &started}))
			if persistErr != nil {
				return Job{}, persistErr
			}
			job = prepared
		}
		result, err = adapter.Submit(ctx, request)
	} else {
		if modeled, ok := adapter.(providers.ModelQueryAdapter); ok {
			result, err = modeled.QueryModel(ctx, job.ProviderTaskID, job.ReqKey)
		} else {
			result, err = adapter.Query(ctx, job.ProviderTaskID)
		}
	}
	if err != nil && job.ProviderTaskID == "" && p.Store != nil {
		failed := StatusFailed
		failure := &JobError{Message: "provider submission outcome is unknown; refusing duplicate submission", Retryable: false}
		return p.Store.UpdateJob(ctx, job.ID, workerPatch(job, Patch{Status: &failed, Error: failure}))
	}
	if err != nil {
		return Job{}, err
	}
	job.ProviderTaskID = result.TaskID
	encoded, err := providers.EncodeResult(result)
	if err != nil {
		return Job{}, errors.New("encode provider result")
	}
	job.ResponsePayload = encoded
	job.Status = Status(result.Status)
	if result.ErrorMessage != "" {
		job.Error = &JobError{Message: result.ErrorMessage}
	}
	if p.Store != nil {
		patch := Patch{Status: &job.Status, ProviderTaskID: &job.ProviderTaskID, ResponsePayload: job.ResponsePayload, SetResponsePayload: true, ClearError: result.ErrorMessage == ""}
		patch.ExpectedStatuses = []Status{expectedStatus}
		if job.LockedBy != "" {
			worker := job.LockedBy
			patch.ExpectedLockedBy = &worker
		}
		if job.Error != nil {
			patch.Error = job.Error
		}
		return p.Store.UpdateJob(ctx, job.ID, patch)
	}
	return job, nil
}

type ProviderJobBuilder struct {
	ImageProvider, VideoProvider string
	ImageModel, VideoModel       string
	ImageEngine, VideoEngine     string
	ImageEngines                 map[string]ProviderTarget
	VideoEngines                 map[string]ProviderTarget
	NewID                        func() string
}

// ProviderTarget is server-owned routing configuration for one UI engine.
// The request may select a known engine, but it cannot supply a provider or
// model directly.
type ProviderTarget struct {
	Provider string
	Model    string
	Settings map[string]any
}

func (b ProviderJobBuilder) Build(_ context.Context, owner, client, capability, idempotency string, body map[string]any) (CreateCommand, error) {
	if capability != "image.generate" && capability != "video.generate" {
		return CreateCommand{}, &Error{Kind: ErrorInvalid, Status: 400, Message: "Unsupported capability: " + capability}
	}
	target, engine, err := b.target(capability, body["engine"])
	if err != nil {
		return CreateCommand{}, err
	}
	if target.Provider == "" || target.Model == "" || b.NewID == nil {
		return CreateCommand{}, errors.New("provider job builder is not configured")
	}
	prepared, err := prepareProviderRequest(capability, engine, target.Settings, body)
	if err != nil {
		return CreateCommand{}, err
	}
	prepared.request.Model = target.Model
	raw, err := json.Marshal(prepared.request)
	if err != nil {
		return CreateCommand{}, errors.New("encode provider request")
	}
	priority := NormalizePriority(intFromAny(body["priority"]))
	webhook, _ := body["webhookUrl"].(string)
	webhook = strings.TrimSpace(webhook)
	if client != "" && webhook != "" && !validWebhookURL(webhook) {
		return CreateCommand{}, invalidPreparation("webhookUrl must be an HTTP or HTTPS URL")
	}
	return CreateCommand{Job: Job{ID: b.NewID(), OwnerID: owner, ExternalClientID: client, Capability: capability, Provider: target.Provider, ReqKey: target.Model, Status: StatusQueued, Prompt: prepared.request.Prompt, InputURLs: prepared.request.InputURLs, InputAssetIDs: prepared.assetIDs, OutputAssetIDs: []string{}, RequestPayload: raw, IdempotencyKey: idempotency, Priority: priority, WebhookURL: webhook}, IdempotencyBody: body}, nil
}

func validWebhookURL(value string) bool {
	parsed, err := url.Parse(value)
	return err == nil && parsed.IsAbs() && parsed.Host != "" && parsed.User == nil && (parsed.Scheme == "http" || parsed.Scheme == "https")
}

func (b ProviderJobBuilder) target(capability string, rawEngine any) (ProviderTarget, string, error) {
	engine := engineName(rawEngine)
	if capability == "image.generate" {
		if rawEngine != nil && engine == "" {
			return ProviderTarget{}, "", invalidPreparation("unsupported image engine")
		}
		if engine != "" {
			if engine != "jimeng" && engine != "evolink" && engine != "bailian" {
				return ProviderTarget{}, "", invalidPreparation("unsupported image engine")
			}
			target, ok := b.ImageEngines[engine]
			if !ok || target.Provider == "" || target.Model == "" {
				return ProviderTarget{}, "", errors.New("provider job builder is not configured")
			}
			return target, engine, nil
		}
		return ProviderTarget{Provider: b.ImageProvider, Model: b.ImageModel}, firstConfiguredEngine(b.ImageEngine, b.ImageProvider, "image"), nil
	}
	if rawEngine != nil && engine == "" {
		return ProviderTarget{}, "", invalidPreparation("unsupported video engine")
	}
	if engine != "" {
		if engine != "seedance" && engine != "bailian" {
			return ProviderTarget{}, "", invalidPreparation("unsupported video engine")
		}
		target, ok := b.VideoEngines[engine]
		if !ok || target.Provider == "" || target.Model == "" {
			return ProviderTarget{}, "", errors.New("provider job builder is not configured")
		}
		return target, engine, nil
	}
	return ProviderTarget{Provider: b.VideoProvider, Model: b.VideoModel}, firstConfiguredEngine(b.VideoEngine, b.VideoProvider, "video"), nil
}

func firstConfiguredEngine(configured, provider, capabilityKind string) string {
	if engine := engineName(configured); engine != "" {
		return engine
	}
	if capabilityKind == "image" {
		switch provider {
		case "volcengine-visual":
			return "jimeng"
		case "evolink", "bailian":
			return provider
		}
	} else if provider == "seedance" || provider == "bailian" {
		return provider
	}
	return ""
}

type preparedProviderRequest struct {
	request  providers.Request
	assetIDs []string
}

func prepareProviderRequest(capability, engine string, defaults map[string]any, body map[string]any) (preparedProviderRequest, error) {
	materials, assembly, err := preparationMaterials(body, capability)
	if err != nil {
		return preparedProviderRequest{}, err
	}
	text := stringValue(body["prompt"])
	if text == "" && assembly != nil {
		text = prompt.Assemble(*assembly).Prompt
	}
	text = strings.TrimSpace(text)
	if text == "" {
		return preparedProviderRequest{}, invalidPreparation("prompt is required")
	}
	assetIDs := stringsFromAny(body["inputAssetIds"])
	if len(assetIDs) == 0 {
		for _, material := range materials {
			if material.ID != "" {
				assetIDs = append(assetIDs, material.ID)
			}
		}
	}
	var urls []string
	var settings map[string]any
	if capability == "image.generate" {
		urls = stringsFromAny(firstNonNil(body["imageUrls"], body["inputUrls"]))
		if len(urls) == 0 {
			for _, material := range materials {
				if material.Type == "image" {
					urls = append(urls, material.URL)
				}
			}
		}
		if err := validateImageCoverage(text, materials, len(urls)); err != nil {
			return preparedProviderRequest{}, err
		}
		settings, err = imageSettings(body)
		if err == nil && engine == "bailian" {
			err = validateBailianImage(urls, settings)
		}
	} else {
		if err := validateMaterialCoverage(text, materials); err != nil {
			return preparedProviderRequest{}, err
		}
		for _, material := range materials {
			urls = append(urls, material.URL)
		}
		settings, err = videoSettings(engine, defaults, body["settings"], materials)
	}
	if err != nil {
		return preparedProviderRequest{}, err
	}
	providerMaterials := make([]providers.Material, 0, len(materials))
	for _, material := range materials {
		materialType := providers.MaterialImage
		switch material.Type {
		case "video":
			materialType = providers.MaterialVideo
		case "audio":
			materialType = providers.MaterialAudio
		}
		providerMaterials = append(providerMaterials, providers.Material{
			URL: material.URL, Type: materialType, Role: material.Role, Label: material.Label,
		})
	}
	return preparedProviderRequest{request: providers.Request{Capability: capability, Prompt: text, InputURLs: urls, Materials: providerMaterials, Settings: settings}, assetIDs: assetIDs}, nil
}

func validateImageCoverage(text string, materials []prompt.Material, imageURLCount int) error {
	required := prompt.ExtractRequirements(text)
	if required.Video > 0 || required.Audio > 0 {
		return validateMaterialCoverage(text, materials)
	}
	if required.Image > imageURLCount {
		return invalidPreparation(fmt.Sprintf("prompt requires @图片%d but only %d image materials were supplied", required.Image, imageURLCount))
	}
	return nil
}

func preparationMaterials(body map[string]any, capability string) ([]prompt.Material, *prompt.Input, error) {
	assemblyRecord, hasAssembly := body["promptAssembly"].(map[string]any)
	var assembly *prompt.Input
	if hasAssembly {
		var decoded prompt.Input
		if err := decodeViaJSON(assemblyRecord, &decoded); err != nil {
			return nil, nil, invalidPreparation("invalid promptAssembly")
		}
		if capability == "image.generate" {
			decoded.Mode = "image"
		} else {
			decoded.Mode = "video"
		}
		assembly = &decoded
	}
	var materials []prompt.Material
	if raw, ok := body["materials"]; ok {
		if err := decodeViaJSON(raw, &materials); err != nil {
			return nil, nil, invalidPreparation("invalid materials")
		}
	} else if assembly != nil {
		materials = assembly.Materials
	}
	materials = prompt.NormalizeMaterials(materials)
	if assembly != nil {
		assembly.Materials = materials
	}
	return materials, assembly, nil
}

func validateMaterialCoverage(text string, materials []prompt.Material) error {
	required := prompt.ExtractRequirements(text)
	available := prompt.Requirements{}
	for _, material := range materials {
		switch material.Type {
		case "video":
			available.Video++
		case "audio":
			available.Audio++
		default:
			available.Image++
		}
	}
	if required.Image > available.Image {
		return invalidPreparation(fmt.Sprintf("prompt requires @图片%d but only %d image materials were supplied", required.Image, available.Image))
	}
	if required.Video > available.Video {
		return invalidPreparation(fmt.Sprintf("prompt requires @视频%d but only %d video materials were supplied", required.Video, available.Video))
	}
	if required.Audio > available.Audio {
		return invalidPreparation(fmt.Sprintf("prompt requires @音频%d but only %d audio materials were supplied", required.Audio, available.Audio))
	}
	return nil
}

func imageSettings(body map[string]any) (map[string]any, error) {
	out := map[string]any{}
	if nested, ok := body["settings"].(map[string]any); ok {
		for _, key := range []string{"scale", "width", "height", "min_ratio", "max_ratio", "imageCount", "force_single", "quality"} {
			if nested[key] != nil {
				out[key] = nested[key]
			}
		}
	}
	for _, key := range []string{"scale", "width", "height", "min_ratio", "max_ratio", "imageCount"} {
		raw := body[key]
		if raw == nil {
			raw = out[key]
		}
		if value, ok := finiteNumber(raw); ok {
			out[key] = value
		} else if raw != nil && raw != "" {
			return nil, invalidPreparation("invalid image parameter: " + key)
		} else {
			delete(out, key)
		}
	}
	forceSingle := body["force_single"]
	if forceSingle == nil {
		forceSingle = out["force_single"]
	}
	if value, ok := forceSingle.(bool); ok {
		out["force_single"] = value
	} else if forceSingle != nil {
		return nil, invalidPreparation("invalid image parameter: force_single")
	} else {
		delete(out, "force_single")
	}
	qualityRaw := body["quality"]
	if qualityRaw == nil {
		qualityRaw = out["quality"]
	}
	delete(out, "quality")
	if raw, ok := qualityRaw.(string); ok {
		quality := strings.ToLower(strings.TrimSpace(raw))
		if quality == "low" || quality == "medium" || quality == "high" {
			out["quality"] = quality
		}
	}
	if count, ok := out["imageCount"].(float64); ok && (count <= 0 || count > 9 || math.Trunc(count) != count) {
		return nil, invalidPreparation("imageCount must be an integer between 1 and 9")
	}
	return out, nil
}

func validateBailianImage(urls []string, settings map[string]any) error {
	if len(urls) > 9 {
		return invalidPreparation("bailian supports at most 9 reference images")
	}
	width, hasWidth := settings["width"].(float64)
	height, hasHeight := settings["height"].(float64)
	if !hasWidth && !hasHeight {
		return nil
	}
	if !hasWidth || !hasHeight || math.Trunc(width) != width || math.Trunc(height) != height || width <= 0 || height <= 0 {
		return invalidPreparation("bailian image dimensions must be positive integers")
	}
	pixels := width * height
	maximum := float64(4096 * 4096)
	if len(urls) > 0 {
		maximum = float64(2048 * 2048)
	}
	if pixels < float64(768*768) || pixels > maximum || width/height < 1.0/8.0 || width/height > 8 {
		return invalidPreparation("bailian image dimensions are outside supported size constraints")
	}
	return nil
}

func videoSettings(engine string, defaults map[string]any, raw any, materials []prompt.Material) (map[string]any, error) {
	input, _ := raw.(map[string]any)
	merged := make(map[string]any, len(defaults)+len(input))
	for key, value := range defaults {
		merged[key] = value
	}
	for key, value := range input {
		merged[key] = value
	}
	input = merged
	settings := map[string]any{}
	if engine == "bailian" {
		if len(materials) < 1 || len(materials) > 2 {
			return nil, invalidPreparation("bailian video requires 1 or 2 image materials")
		}
		for _, material := range materials {
			if material.Type != "image" {
				return nil, invalidPreparation("bailian video requires 1 or 2 image materials")
			}
		}
		duration := float64(10)
		if input["duration"] != nil {
			var ok bool
			duration, ok = finiteNumber(input["duration"])
			if !ok || math.Trunc(duration) != duration || duration < 2 || duration > 15 {
				return nil, invalidPreparation("bailian video duration must be an integer between 2 and 15 seconds")
			}
		}
		resolution := strings.ToUpper(stringValue(input["resolution"]))
		if resolution == "" {
			resolution = "720P"
		}
		if resolution != "720P" && resolution != "1080P" {
			return nil, invalidPreparation("bailian video resolution must be 720P or 1080P")
		}
		return map[string]any{"duration": duration, "resolution": resolution}, nil
	}
	if engine != "" && engine != "seedance" {
		return nil, invalidPreparation("unsupported video engine")
	}
	ratio := stringValue(input["ratio"])
	if ratio != "" && !oneOf(ratio, "9:16", "16:9", "1:1", "4:3", "3:4", "21:9", "adaptive") {
		return nil, invalidPreparation("unsupported video ratio")
	}
	if ratio != "" {
		settings["ratio"] = ratio
	}
	if input["duration"] != nil {
		duration, ok := finiteNumber(input["duration"])
		if !ok || math.Trunc(duration) != duration || duration < 4 || duration > 15 {
			return nil, invalidPreparation("video duration must be an integer between 4 and 15 seconds")
		}
		settings["duration"] = duration
	}
	resolution := stringValue(input["resolution"])
	if resolution != "" && !oneOf(resolution, "480p", "720p", "1080p", "4k") {
		return nil, invalidPreparation("unsupported video resolution")
	}
	if resolution != "" {
		settings["resolution"] = resolution
	}
	return settings, nil
}

func invalidPreparation(message string) error {
	return &Error{Kind: ErrorInvalid, Status: 400, Message: message}
}

func decodeViaJSON(input, output any) error {
	raw, err := json.Marshal(input)
	if err != nil {
		return err
	}
	return json.Unmarshal(raw, output)
}

func finiteNumber(value any) (float64, bool) {
	var number float64
	switch typed := value.(type) {
	case float64:
		number = typed
	case float32:
		number = float64(typed)
	case int:
		number = float64(typed)
	case int64:
		number = float64(typed)
	default:
		return 0, false
	}
	return number, !math.IsNaN(number) && !math.IsInf(number, 0)
}

func stringValue(value any) string {
	text, _ := value.(string)
	return strings.TrimSpace(text)
}

func engineName(value any) string { return strings.ToLower(stringValue(value)) }

func oneOf(value string, options ...string) bool {
	for _, option := range options {
		if value == option {
			return true
		}
	}
	return false
}

func stringsFromAny(v any) []string {
	if values, ok := v.([]string); ok {
		out := make([]string, 0, len(values))
		for _, value := range values {
			if value = strings.TrimSpace(value); value != "" {
				out = append(out, value)
			}
		}
		return out
	}
	values, _ := v.([]any)
	out := []string{}
	for _, x := range values {
		if s, ok := x.(string); ok && strings.TrimSpace(s) != "" {
			out = append(out, strings.TrimSpace(s))
		}
	}
	return out
}
func intFromAny(v any) int {
	switch x := v.(type) {
	case float64:
		return int(x)
	case int:
		return x
	}
	return 0
}
func firstNonNil(v ...any) any {
	for _, x := range v {
		if x != nil {
			return x
		}
	}
	return nil
}