package promptkitadapter

import (
	"context"
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"sync"
	"testing"
	"time"

	promptkit "gitea.maximumdirect.net/eric/promptkit"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/promptexec"
)

type fakeClient struct {
	mu       sync.Mutex
	response *promptkit.GenerateResponse
	err      error
	calls    int
	requests []promptkit.GenerateRequest
	block    bool
}

type recordingReader struct {
	ref promptkit.ArtifactRef
}

func (reader *recordingReader) Read(_ context.Context, ref promptkit.ArtifactRef) (*promptkit.Artifact, error) {
	reader.ref = ref
	return &promptkit.Artifact{
		Name:        "data_package",
		ContentType: "application/yaml",
		Body:        []byte(ref.Body),
		URI:         ref.URI,
		Hash:        "input-hash",
	}, nil
}

func (client *fakeClient) Generate(ctx context.Context, request promptkit.GenerateRequest) (*promptkit.GenerateResponse, error) {
	client.mu.Lock()
	client.calls++
	client.requests = append(client.requests, request)
	block := client.block
	response := client.response
	err := client.err
	client.mu.Unlock()
	if block {
		<-ctx.Done()
		return nil, ctx.Err()
	}
	return response, err
}

func (client *fakeClient) callCount() int {
	client.mu.Lock()
	defer client.mu.Unlock()
	return client.calls
}

func (client *fakeClient) request() promptkit.GenerateRequest {
	client.mu.Lock()
	defer client.mu.Unlock()
	return client.requests[0]
}

func TestInspectPromptAndProfile(t *testing.T) {
	adapter := newTestAdapter(t, &fakeClient{})
	inspection, err := adapter.InspectPrompt(context.Background(), "weather.daily_generated_text", "2.0.0")
	if err != nil {
		t.Fatalf("InspectPrompt() error = %v", err)
	}
	if inspection.PromptID != "weather.daily_generated_text" || inspection.PromptVersion != "2.0.0" || inspection.DefaultProfileID != "weather-balanced" {
		t.Fatalf("inspection = %#v", inspection)
	}
	if len(inspection.Inputs) != 1 || inspection.Inputs[0].Name != "data_package" || !inspection.Inputs[0].Required || inspection.Inputs[0].ContentType != "application/yaml" {
		t.Fatalf("inputs = %#v", inspection.Inputs)
	}
	if inspection.Output.Format != "json" || inspection.Output.ValidationMode != "json_schema" || inspection.Output.SchemaPath != "daily.generated_text.schema.json" {
		t.Fatalf("output = %#v", inspection.Output)
	}

	profile, err := adapter.InspectProfile(context.Background(), "test-profile")
	if err != nil {
		t.Fatalf("InspectProfile() error = %v", err)
	}
	if profile.ProfileID != "test-profile" || profile.BackendID != "" || profile.ModelName != "test-model" || profile.CredentialRequired {
		t.Fatalf("profile = %#v", profile)
	}
	if strings.Contains(fmt.Sprintf("%#v", profile), "https://profile.example") {
		t.Fatalf("profile leaks endpoint: %#v", profile)
	}

	builtin, err := adapter.InspectProfile(context.Background(), "gemini-flash-latest")
	if err != nil {
		t.Fatalf("InspectProfile(builtin) error = %v", err)
	}
	if builtin.ProfileID != "gemini-flash-latest" || builtin.ModelName == "" {
		t.Fatalf("builtin profile = %#v", builtin)
	}
}

func TestEmbeddedProfilesAreAvailableToProductionAndTestAdapters(t *testing.T) {
	adapter, err := New(Config{})
	if err != nil {
		t.Fatalf("New() error = %v", err)
	}
	for _, want := range []struct {
		id      string
		backend string
		model   string
	}{
		{"weather-light", "openrouter", "deepseek/deepseek-v4-flash"},
		{"weather-balanced", "openrouter", "~google/gemini-flash-latest"},
		{"weather-deep", "openrouter", "~anthropic/claude-sonnet-latest"},
	} {
		t.Run(want.id, func(t *testing.T) {
			assertProfile(t, adapter, want.id, want.backend, want.model)
		})
	}

	testAdapter, err := newAdapterForTest(Config{}, &fakeClient{})
	if err != nil {
		t.Fatalf("newAdapterForTest() error = %v", err)
	}
	assertProfile(t, testAdapter, "weather-light", "openrouter", "deepseek/deepseek-v4-flash")
}

func TestConfiguredProfilesOverrideEmbeddedFallbacks(t *testing.T) {
	file := writeProfileFile(t, `id: weather-light
endpoint: https://local-file.example/v1
model: file-light
`)
	fileAdapter, err := New(Config{ProfileFile: file})
	if err != nil {
		t.Fatalf("New(profile file) error = %v", err)
	}
	assertProfile(t, fileAdapter, "weather-light", "", "file-light")

	directory := testProfileDirectory(t, `id: weather-light
backend: local
model: directory-light
`)
	directoryAdapter, err := New(Config{ProfileDirectory: directory, LocalEndpoint: "https://local-directory.example/v1"})
	if err != nil {
		t.Fatalf("New(profile directory) error = %v", err)
	}
	assertProfile(t, directoryAdapter, "weather-light", promptkit.BackendLocal, "directory-light")
}

func TestMaintainedWeatherLightLocalProfileExampleInspectsOffline(t *testing.T) {
	adapter, err := New(Config{ProfileFile: filepath.Join("..", "..", "..", "examples", "weather-light-local-profile.yml")})
	if err != nil {
		t.Fatalf("New() error = %v", err)
	}
	assertProfile(t, adapter, "weather-light", "", "weather-local")
}

func TestProfileResolutionFallsThroughOnlyWhenTheConfiguredIDIsAbsent(t *testing.T) {
	absentAdapter, err := New(Config{ProfileDirectory: testProfileDirectory(t, `id: other-profile
backend: openrouter
model: other-model
`)})
	if err != nil {
		t.Fatalf("New(absent profile) error = %v", err)
	}
	assertProfile(t, absentAdapter, "weather-light", "openrouter", "deepseek/deepseek-v4-flash")

	malformedAdapter, err := New(Config{ProfileDirectory: testProfileDirectory(t, `id: weather-light
backend: openrouter
`)})
	if err != nil {
		t.Fatalf("New(malformed profile) error = %v", err)
	}
	if _, err := malformedAdapter.InspectProfile(context.Background(), "weather-light"); err == nil {
		t.Fatal("InspectProfile() error = nil, want malformed configured profile error")
	}
}

func TestProfileResolutionPreservesBuiltInAndExplicitPrecedence(t *testing.T) {
	adapter, err := New(Config{})
	if err != nil {
		t.Fatalf("New() error = %v", err)
	}
	builtin, err := adapter.InspectProfile(context.Background(), "gemini-flash-latest")
	if err != nil {
		t.Fatalf("InspectProfile(builtin) error = %v", err)
	}
	if builtin.ProfileID != "gemini-flash-latest" || builtin.BackendID != "openrouter" || builtin.ModelName == "" {
		t.Fatalf("builtin profile = %#v", builtin)
	}

	explicit, err := newAdapter(Config{}, promptkit.WithProfiles(promptkit.Profile{
		ID:       "weather-light",
		Endpoint: "https://explicit.example/v1",
		Model:    "explicit-light",
	}))
	if err != nil {
		t.Fatalf("newAdapter(explicit profile) error = %v", err)
	}
	assertProfile(t, explicit, "weather-light", "", "explicit-light")
}

func TestExecuteUsesPreparedInlineDataPackage(t *testing.T) {
	client := &fakeClient{response: validResponse()}
	adapter := newTestAdapter(t, client)
	request := testExecuteRequest()
	callbackCalls := 0
	result, err := adapter.Execute(context.Background(), request, func(preparation promptexec.Preparation, debug *promptexec.PreparationDebug) error {
		callbackCalls++
		if preparation.PromptID != request.PromptID || preparation.PromptVersion != request.PromptVersion || preparation.ModelName != "test-model" {
			t.Fatalf("preparation = %#v", preparation)
		}
		if debug != nil {
			t.Fatalf("debug = %#v, want nil", debug)
		}
		if client.callCount() != 0 {
			t.Fatal("provider called before preparation callback")
		}
		return nil
	})
	if err != nil {
		t.Fatalf("Execute() error = %v", err)
	}
	if callbackCalls != 1 || client.callCount() != 1 {
		t.Fatalf("callback/provider calls = %d/%d, want 1/1", callbackCalls, client.callCount())
	}
	if result == nil || result.Validation.Status != promptexec.ValidationPassed || string(result.RawOutput) != client.response.Content {
		t.Fatalf("result = %#v", result)
	}
	if result.Debug != nil {
		t.Fatalf("debug = %#v, want nil", result.Debug)
	}
	providerRequest := client.request()
	if providerRequest.Target.Model != "test-model" || providerRequest.Target.Endpoint != "https://profile.example/v1" {
		t.Fatalf("provider target = %#v", providerRequest.Target)
	}
	if len(providerRequest.Prompt.Messages) == 0 || !strings.Contains(providerRequest.Prompt.Messages[2].Content, string(request.DataPackage)) {
		t.Fatalf("rendered messages do not contain exact data package: %#v", providerRequest.Prompt.Messages)
	}
}

func TestExecuteEmbeddedHourlyProfileThroughPreparedPath(t *testing.T) {
	t.Setenv("OPENROUTER_API_KEY", "test-openrouter-key")
	client := &fakeClient{response: hourlyValidResponse()}
	adapter, err := newAdapter(Config{}, promptkit.WithLLMClient(client))
	if err != nil {
		t.Fatalf("newAdapter() error = %v", err)
	}
	request := promptexec.ExecuteRequest{
		PromptID:      "weather.hourly_generated_text",
		PromptVersion: "2.0.0",
		ProfileID:     "weather-light",
		DataPackage:   []byte("report:\n  id: hourly\nbriefing: {}\n"),
	}
	var preparation promptexec.Preparation
	prepared := false
	result, err := adapter.Execute(context.Background(), request, func(value promptexec.Preparation, _ *promptexec.PreparationDebug) error {
		if client.callCount() != 0 {
			t.Fatal("provider was called before preparation completed")
		}
		preparation = value
		prepared = true
		return nil
	})
	if err != nil {
		t.Fatalf("Execute() error = %v", err)
	}
	if !prepared || preparation.ProfileID != "weather-light" || preparation.BackendID != "openrouter" || preparation.ModelName != "deepseek/deepseek-v4-flash" {
		t.Fatalf("preparation = %#v", preparation)
	}
	if result == nil || result.ProfileID != "weather-light" || result.BackendID != "openrouter" || result.ModelName != "deepseek/deepseek-v4-flash" || result.Validation.Status != promptexec.ValidationPassed {
		t.Fatalf("execution = %#v", result)
	}
	if client.callCount() != 1 || client.request().Target.Model != "deepseek/deepseek-v4-flash" {
		t.Fatalf("provider calls/request = %d/%#v", client.callCount(), client.request())
	}
}

func TestExecuteUsesExactInlineDataPackageProvenance(t *testing.T) {
	client := &fakeClient{response: validResponse()}
	reader := &recordingReader{}
	adapter := newTestAdapterWithOptions(t, client, promptkit.WithArtifactReader(reader))
	request := testExecuteRequest()
	if _, err := adapter.Execute(context.Background(), request, nil); err != nil {
		t.Fatalf("Execute() error = %v", err)
	}
	if reader.ref.Type != promptkit.ArtifactRefInline || reader.ref.URI != "" || reader.ref.Body != string(request.DataPackage) {
		t.Fatalf("artifact ref = %#v, want exact inline data package provenance", reader.ref)
	}
}

func TestExecuteCapturesSensitiveDebugOnlyWhenRequested(t *testing.T) {
	client := &fakeClient{response: validResponse()}
	adapter := newTestAdapter(t, client)
	request := testExecuteRequest()
	request.CaptureDebug = true
	var preparationDebug *promptexec.PreparationDebug
	result, err := adapter.Execute(context.Background(), request, func(preparation promptexec.Preparation, debug *promptexec.PreparationDebug) error {
		preparationDebug = debug
		if strings.Contains(fmt.Sprintf("%#v", preparation), "https://profile.example") || strings.Contains(fmt.Sprintf("%#v", preparation), string(request.DataPackage)) {
			t.Fatalf("safe preparation leaks sensitive content: %#v", preparation)
		}
		return nil
	})
	if err != nil {
		t.Fatalf("Execute() error = %v", err)
	}
	if preparationDebug == nil || preparationDebug.Endpoint != "https://profile.example/v1" || len(preparationDebug.RenderedMessages) == 0 || len(preparationDebug.StructuredSchema) == 0 || len(preparationDebug.ParametersJSON) == 0 {
		t.Fatalf("preparation debug = %#v", preparationDebug)
	}
	if result.Debug == nil || string(result.Debug.RawOutput) != client.response.Content {
		t.Fatalf("execution debug = %#v", result.Debug)
	}
}

func TestExecuteCallbackFailurePreventsGeneration(t *testing.T) {
	client := &fakeClient{response: validResponse()}
	adapter := newTestAdapter(t, client)
	callbackError := errors.New("save preparation")
	result, err := adapter.Execute(context.Background(), testExecuteRequest(), func(promptexec.Preparation, *promptexec.PreparationDebug) error {
		return callbackError
	})
	if result != nil || !errors.Is(err, callbackError) || client.callCount() != 0 {
		t.Fatalf("result/error/provider calls = %#v/%v/%d", result, err, client.callCount())
	}
}

func TestExecuteReturnsCompletedValidationRejection(t *testing.T) {
	client := &fakeClient{response: &promptkit.GenerateResponse{Content: `{"summary":42}`, Usage: promptkit.TokenUsage{TotalTokens: 5}}}
	adapter := newTestAdapter(t, client)
	result, err := adapter.Execute(context.Background(), testExecuteRequest(), nil)
	if err != nil {
		t.Fatalf("Execute() error = %v", err)
	}
	if result == nil || result.Validation.Status != promptexec.ValidationFailed || len(result.Validation.Diagnostics) == 0 || string(result.RawOutput) != client.response.Content {
		t.Fatalf("result = %#v", result)
	}
}

func TestExecuteClassifiesOperationalFailures(t *testing.T) {
	tests := []struct {
		name     string
		client   *fakeClient
		context  func() (context.Context, context.CancelFunc)
		category promptexec.ErrorCategory
	}{
		{
			name:   "generation",
			client: &fakeClient{err: errors.New("provider response body")},
			context: func() (context.Context, context.CancelFunc) {
				return context.WithCancel(context.Background())
			},
			category: promptexec.Generation,
		},
		{
			name:   "canceled",
			client: &fakeClient{block: true},
			context: func() (context.Context, context.CancelFunc) {
				ctx, cancel := context.WithCancel(context.Background())
				cancel()
				return ctx, func() {}
			},
			category: promptexec.Canceled,
		},
		{
			name:   "deadline",
			client: &fakeClient{block: true},
			context: func() (context.Context, context.CancelFunc) {
				return context.WithTimeout(context.Background(), time.Nanosecond)
			},
			category: promptexec.DeadlineExceeded,
		},
	}
	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			adapter := newTestAdapter(t, test.client)
			ctx, cancel := test.context()
			defer cancel()
			result, err := adapter.Execute(ctx, testExecuteRequest(), nil)
			if result != nil || err == nil || promptexec.CategoryOf(err) != test.category {
				t.Fatalf("result/error/category = %#v/%v/%q, want %q", result, err, promptexec.CategoryOf(err), test.category)
			}
			if strings.Contains(err.Error(), "provider response body") {
				t.Fatalf("error leaks provider detail: %v", err)
			}
		})
	}
}

func TestClassifyPromptkitErrors(t *testing.T) {
	tests := []struct {
		err      error
		category promptexec.ErrorCategory
	}{
		{promptkit.ErrInvalidConfig, promptexec.InvalidConfiguration},
		{promptkit.ErrInvalidRequest, promptexec.InvalidRequest},
		{promptkit.ErrPromptNotFound, promptexec.PromptNotFound},
		{promptkit.ErrPromptLoad, promptexec.PromptLoad},
		{promptkit.ErrProfileNotFound, promptexec.ProfileNotFound},
		{promptkit.ErrProfileLoad, promptexec.ProfileLoad},
		{promptkit.ErrAPIKeyEnvMissing, promptexec.MissingCredential},
		{promptkit.ErrArtifactLoad, promptexec.ArtifactLoad},
		{promptkit.ErrPromptRender, promptexec.PromptRender},
		{promptkit.ErrLLMGenerate, promptexec.Generation},
		{promptkit.ErrValidation, promptexec.OperationalValidation},
		{&promptkit.CapacityError{BackendID: "local"}, promptexec.Capacity},
	}
	for _, test := range tests {
		t.Run(string(test.category), func(t *testing.T) {
			got := classifyError(test.err)
			if promptexec.CategoryOf(got) != test.category {
				t.Fatalf("category = %q, want %q", promptexec.CategoryOf(got), test.category)
			}
		})
	}
}

func TestNewValidatesConfiguration(t *testing.T) {
	if _, err := New(Config{ProfileDirectory: "profiles", ProfileFile: "profile.yml"}); promptexec.CategoryOf(err) != promptexec.InvalidConfiguration {
		t.Fatalf("profile source error = %v", err)
	}
	if _, err := New(Config{LocalConcurrencyLimit: 1}); promptexec.CategoryOf(err) != promptexec.InvalidConfiguration {
		t.Fatalf("local concurrency error = %v", err)
	}
	if _, err := New(Config{LocalEndpoint: "not a URL"}); promptexec.CategoryOf(err) != promptexec.InvalidConfiguration {
		t.Fatalf("local endpoint error = %v", err)
	}
}

func TestLocalBackendAndMissingCredentialBehavior(t *testing.T) {
	profiles := testProfileDirectory(t, `id: local-profile
backend: local
model: local-model
`)
	adapter, err := newAdapterForTest(Config{
		ProfileDirectory:      profiles,
		LocalEndpoint:         "https://local.example/v1",
		LocalConcurrencyLimit: 1,
	}, &fakeClient{})
	if err != nil {
		t.Fatalf("newAdapterForTest(local) error = %v", err)
	}
	profile, err := adapter.InspectProfile(context.Background(), "local-profile")
	if err != nil || profile.BackendID != promptkit.BackendLocal || profile.ModelName != "local-model" {
		t.Fatalf("local profile/error = %#v/%v", profile, err)
	}
	if got := classifyError(&promptkit.CapacityError{BackendID: promptkit.BackendLocal}); promptexec.CategoryOf(got) != promptexec.Capacity {
		t.Fatalf("capacity classification = %v", got)
	}

	credentialProfiles := testProfileDirectory(t, `id: credential-profile
endpoint: https://profile.example/v1
model: test-model
api_key_env: WEATHERREPORTER_TEST_MISSING_KEY
`)
	client := &fakeClient{response: validResponse()}
	credentialAdapter, err := newAdapterForTest(Config{ProfileDirectory: credentialProfiles}, client)
	if err != nil {
		t.Fatalf("newAdapterForTest(credential) error = %v", err)
	}
	credentialProfile, err := credentialAdapter.InspectProfile(context.Background(), "credential-profile")
	if err != nil || credentialProfile.CredentialRequired || credentialProfile.APIKeyEnv != "WEATHERREPORTER_TEST_MISSING_KEY" {
		t.Fatalf("credential profile/error = %#v/%v", credentialProfile, err)
	}
	request := testExecuteRequest()
	request.ProfileID = "credential-profile"
	result, err := credentialAdapter.Execute(context.Background(), request, nil)
	if result != nil || promptexec.CategoryOf(err) != promptexec.MissingCredential || client.callCount() != 0 {
		t.Fatalf("credential result/category/calls = %#v/%q/%d", result, promptexec.CategoryOf(err), client.callCount())
	}
}

func newTestAdapter(t *testing.T, client promptkit.LLMClient) *Adapter {
	return newTestAdapterWithOptions(t, client)
}

func assertProfile(t *testing.T, adapter *Adapter, id string, backend string, model string) {
	t.Helper()
	profile, err := adapter.InspectProfile(context.Background(), id)
	if err != nil {
		t.Fatalf("InspectProfile(%q) error = %v", id, err)
	}
	if profile.ProfileID != id || profile.BackendID != backend || profile.ModelName != model {
		t.Fatalf("profile = %#v, want %q with backend/model %q/%q", profile, id, backend, model)
	}
}

func newTestAdapterWithOptions(t *testing.T, client promptkit.LLMClient, options ...promptkit.Option) *Adapter {
	t.Helper()
	profiles := testProfileDirectory(t, `id: test-profile
endpoint: https://profile.example/v1
model: test-model
temperature: 0.2
max_tokens: 300
top_p: 1
timeout_seconds: 30
`)
	options = append(options, promptkit.WithLLMClient(client))
	adapter, err := newAdapter(Config{ProfileDirectory: profiles, Timeout: time.Second}, options...)
	if err != nil {
		t.Fatalf("newAdapter() error = %v", err)
	}
	return adapter
}

func testProfileDirectory(t *testing.T, profile string) string {
	t.Helper()
	profiles := t.TempDir()
	if err := os.WriteFile(filepath.Join(profiles, "profile.yml"), []byte(profile), 0o600); err != nil {
		t.Fatalf("write profile: %v", err)
	}
	return profiles
}

func writeProfileFile(t *testing.T, profile string) string {
	t.Helper()
	path := filepath.Join(t.TempDir(), "profile.yml")
	if err := os.WriteFile(path, []byte(profile), 0o600); err != nil {
		t.Fatalf("write profile: %v", err)
	}
	return path
}

func testExecuteRequest() promptexec.ExecuteRequest {
	return promptexec.ExecuteRequest{
		PromptID:      "weather.daily_generated_text",
		PromptVersion: "2.0.0",
		ProfileID:     "test-profile",
		DataPackage:   []byte("report:\n  id: daily\nbriefing: {}\n"),
	}
}

func validResponse() *promptkit.GenerateResponse {
	return &promptkit.GenerateResponse{
		Content: `{"summary":"A quiet day is expected.","forecast_discussion":["High pressure keeps conditions settled."],"precipitation_timing":""}`,
		Usage:   promptkit.TokenUsage{PromptTokens: 12, CompletionTokens: 8, TotalTokens: 20},
	}
}

func hourlyValidResponse() *promptkit.GenerateResponse {
	return &promptkit.GenerateResponse{
		Content: `{"summary":"A quiet hour is expected.","forecast_discussion":"Conditions remain settled.","precipitation_timing":""}`,
		Usage:   promptkit.TokenUsage{PromptTokens: 12, CompletionTokens: 8, TotalTokens: 20},
	}
}