package contracts

import (
	"context"
	"encoding/json"
	"reflect"
	"testing"

	"gitea.maximumdirect.net/eric/notarius/internal/core/artifacts"
	"gitea.maximumdirect.net/eric/notarius/internal/core/source"
)

var _ InputAdapter = fakeAdapter{}
var _ Chunker = fakeChunker{}
var _ Extractor[fakeArtifact] = fakeExtractor{}
var _ Merger[fakeArtifact] = fakeMerger{}
var _ Normalizer[fakeArtifact] = fakeNormalizer{}
var _ StructuredLLMClient = fakeLLMClient{}
var _ OutputEncoder = fakeOutputEncoder{}

func TestFakeExtractorReturnsTypedOutput(t *testing.T) {
	extractor := fakeExtractor{
		key: "generic-extractor",
	}
	doc := &source.SourceDocument{
		ID:     "source-1",
		Kind:   "document",
		Format: "text/plain",
		Digest: "sha256:abc123",
		Units: []source.SourceUnit{
			{ID: 1, Kind: "section", Text: "Source text."},
		},
	}

	result, err := extractor.Extract(context.Background(), TypedExtractionRequest{Source: doc})
	if err != nil {
		t.Fatalf("Extract() error = %v, want nil", err)
	}

	if extractor.Key() != "generic-extractor" {
		t.Fatalf("Key() = %q, want generic-extractor", extractor.Key())
	}
	if result.Value.Value != "example" {
		t.Fatalf("Value = %q, want example", result.Value.Value)
	}
}

func TestFakeChunkerReturnsSourcePlan(t *testing.T) {
	doc := &source.SourceDocument{
		ID:     "source-1",
		Kind:   "document",
		Format: "text/plain",
		Digest: "sha256:abc123",
		Units: []source.SourceUnit{
			{ID: 1, Kind: "section", Text: "Source text."},
		},
	}
	chunker := fakeChunker{key: "generic-chunker"}

	result, err := chunker.Plan(context.Background(), ChunkRequest{Source: doc})
	if err != nil {
		t.Fatalf("Plan() error = %v, want nil", err)
	}

	if chunker.Key() != "generic-chunker" {
		t.Fatalf("Key() = %q, want generic-chunker", chunker.Key())
	}
	if len(result.Plan.Ranges) != 1 {
		t.Fatalf("len(Ranges) = %d, want 1", len(result.Plan.Ranges))
	}
	if result.Plan.SourceDigest != doc.Digest || result.Plan.Ranges[0].StartUnitID != 1 || result.Plan.Ranges[0].EndUnitID != 1 {
		t.Fatalf("Plan = %#v, want source digest and unit range", result.Plan)
	}
}

func TestFakeChunkerReceivesPerRunContext(t *testing.T) {
	doc := &source.SourceDocument{
		ID:     "source-1",
		Kind:   "document",
		Format: "text/plain",
		Digest: "sha256:abc123",
		Units: []source.SourceUnit{
			{ID: 1, Kind: "section", Text: "Source text."},
		},
	}
	chunker := &recordingChunker{key: "llm-chunker"}

	if _, err := chunker.Plan(context.Background(), ChunkRequest{Source: doc, SessionID: "session", LLMProfile: "profile"}); err != nil {
		t.Fatalf("Plan() error = %v, want nil", err)
	}
	if chunker.request.SessionID != "session" || chunker.request.LLMProfile != "profile" {
		t.Fatalf("ChunkRequest = %#v, want per-run session and profile", chunker.request)
	}
}

func TestFakeExtractorReceivesChunkAndAmbientContext(t *testing.T) {
	extractor := fakeExtractor{key: "generic-extractor"}
	doc := &source.SourceDocument{
		ID:     "source-1",
		Kind:   "document",
		Format: "text/plain",
		Digest: "sha256:abc123",
		Units: []source.SourceUnit{
			{ID: 1, Kind: "section", Text: "First source text."},
			{ID: 2, Kind: "section", Text: "Second source text."},
		},
	}
	chunk := source.Chunk{
		ID:        "source-1:chunk:1",
		SourceID:  doc.ID,
		Index:     1,
		Ref:       source.SourceRef{SourceID: doc.ID, StartUnitID: 2, EndUnitID: 2},
		Content:   []byte(`{"units":[{"id":2,"kind":"section","text":"Second source text."}]}`),
		MediaType: "application/json",
		Units:     []source.SourceUnit{doc.Units[1]},
	}

	result, err := extractor.Extract(context.Background(), TypedExtractionRequest{
		Source:         doc,
		Chunk:          &chunk,
		AmbientContext: map[string]any{"mode": "chunked"},
	})
	if err != nil {
		t.Fatalf("Extract() error = %v, want nil", err)
	}
	if result.Value.Value != "chunked" {
		t.Fatalf("Value = %q, want chunked", result.Value.Value)
	}
}

func TestReferenceSetDataTypes(t *testing.T) {
	references := ReferenceSet{
		Slots: map[string]ResolvedReferenceSlot{
			"roster": {
				Slot: ReferenceSlot{
					Name:               "roster",
					Description:        "Known characters",
					Required:           true,
					AcceptedMediaTypes: []string{"text/plain"},
					Multiple:           true,
					MaxBytes:           4096,
				},
				Items: []ReferenceItem{
					{
						SlotName:  "roster",
						MediaType: "text/plain",
						Content:   []byte("Aria\nBryn\n"),
						Digest:    "sha256:reference",
						Origin: ReferenceOrigin{
							Type: "file",
							URI:  "file:///tmp/roster.txt",
						},
						SizeBytes:     10,
						BindingSource: ReferenceBindingSourceConfig,
					},
				},
			},
		},
	}

	item := references.Slots["roster"].Items[0]
	if item.SlotName != "roster" || item.MediaType != "text/plain" || string(item.Content) != "Aria\nBryn\n" {
		t.Fatalf("reference item = %#v, want constructed item fields", item)
	}
	if item.BindingSource != ReferenceBindingSourceConfig {
		t.Fatalf("BindingSource = %q, want %q", item.BindingSource, ReferenceBindingSourceConfig)
	}
}

func TestCloneReferenceSlotsEmptyInputReturnsNil(t *testing.T) {
	if got := CloneReferenceSlots(nil); got != nil {
		t.Fatalf("CloneReferenceSlots(nil) = %#v, want nil", got)
	}
	if got := CloneReferenceSlots([]ReferenceSlot{}); got != nil {
		t.Fatalf("CloneReferenceSlots(empty) = %#v, want nil", got)
	}
}

func TestCloneReferenceSlotsPreservesFields(t *testing.T) {
	slots := []ReferenceSlot{
		{
			Name:               "roster",
			Description:        "Known characters",
			Required:           true,
			AcceptedMediaTypes: []string{"text/plain", "text/markdown"},
			Multiple:           true,
			MaxBytes:           4096,
		},
		{
			Name:        "glossary",
			Description: "Campaign terms",
			MaxBytes:    2048,
		},
	}

	got := CloneReferenceSlots(slots)

	if !reflect.DeepEqual(got, slots) {
		t.Fatalf("CloneReferenceSlots() = %#v, want %#v", got, slots)
	}
}

func TestCloneReferenceSlotsCopiesAcceptedMediaTypes(t *testing.T) {
	slots := []ReferenceSlot{
		{
			Name:               "party",
			AcceptedMediaTypes: []string{"application/json", "text/plain"},
		},
	}

	got := CloneReferenceSlots(slots)
	got[0].Name = "changed"
	got[0].AcceptedMediaTypes[0] = "text/markdown"

	if slots[0].Name != "party" {
		t.Fatalf("source slot name = %q, want unchanged", slots[0].Name)
	}
	if slots[0].AcceptedMediaTypes[0] != "application/json" {
		t.Fatalf("source AcceptedMediaTypes aliased clone: %#v", slots[0].AcceptedMediaTypes)
	}
}

func TestReferenceItemJSONOmitsContent(t *testing.T) {
	item := ReferenceItem{
		SlotName:  "roster",
		MediaType: "text/plain",
		Content:   []byte("reference content"),
		Digest:    "sha256:reference",
		Origin:    ReferenceOrigin{Type: "file", URI: "file:///tmp/roster.txt"},
	}

	encoded, err := json.Marshal(item)
	if err != nil {
		t.Fatalf("json.Marshal() error = %v, want nil", err)
	}

	var got map[string]any
	if err := json.Unmarshal(encoded, &got); err != nil {
		t.Fatalf("json.Unmarshal() error = %v, want nil", err)
	}
	if _, ok := got["content"]; ok {
		t.Fatalf("encoded reference item leaked content: %s", encoded)
	}
	if _, ok := got["Content"]; ok {
		t.Fatalf("encoded reference item leaked Content: %s", encoded)
	}
}

func TestLLMInputMaterialCopiesContentAndOmitsContentFromJSON(t *testing.T) {
	content := []byte("raw source bytes")
	material := NewLLMInputMaterial("transcript", "application/json", content, "sha256:source", "file:///tmp/source.json")
	content[0] = 'R'
	if got := string(material.Content); got != "raw source bytes" {
		t.Fatalf("material content = %q, want defensive copy", got)
	}
	if material.SizeBytes != int64(len("raw source bytes")) {
		t.Fatalf("SizeBytes = %d, want content length", material.SizeBytes)
	}

	clone := material.Clone()
	clone.Content[0] = 'X'
	if got := string(material.Content); got != "raw source bytes" {
		t.Fatalf("cloned material content aliased original: %q", got)
	}

	encoded, err := json.Marshal(material)
	if err != nil {
		t.Fatalf("json.Marshal() error = %v, want nil", err)
	}
	var got map[string]any
	if err := json.Unmarshal(encoded, &got); err != nil {
		t.Fatalf("json.Unmarshal() error = %v, want nil", err)
	}
	if _, ok := got["content"]; ok {
		t.Fatalf("encoded material leaked content: %s", encoded)
	}
	if _, ok := got["Content"]; ok {
		t.Fatalf("encoded material leaked Content: %s", encoded)
	}
	if got["digest"] != "sha256:source" || got["origin_uri"] != "file:///tmp/source.json" {
		t.Fatalf("encoded material = %#v, want non-secret provenance", got)
	}
}

func TestLLMInputSetCloneCopiesContent(t *testing.T) {
	set := LLMInputSet{
		"transcript": NewLLMInputMaterial("transcript", "application/json", []byte("source"), "sha256:source", "file:///tmp/source.json"),
	}
	clone := set.Clone()
	clone["transcript"].Content[0] = 'S'
	if got := string(set["transcript"].Content); got != "source" {
		t.Fatalf("input set clone aliased content: %q", got)
	}
}

func TestArtifactSchemaJSONOmitsSchemaContent(t *testing.T) {
	schema := ArtifactSchema{
		ID:         "schema-id",
		Name:       "schema-name",
		Version:    "v1",
		JSONSchema: []byte(`{"type":"object"}`),
	}
	encoded, err := json.Marshal(schema)
	if err != nil {
		t.Fatalf("json.Marshal() error = %v, want nil", err)
	}
	var got map[string]any
	if err := json.Unmarshal(encoded, &got); err != nil {
		t.Fatalf("json.Unmarshal() error = %v, want nil", err)
	}
	if got["id"] != "schema-id" || got["name"] != "schema-name" || got["version"] != "v1" {
		t.Fatalf("encoded schema = %#v, want schema provenance", got)
	}
	if _, ok := got["json_schema"]; ok {
		t.Fatalf("encoded schema leaked raw schema content: %s", encoded)
	}
	if _, ok := got["JSONSchema"]; ok {
		t.Fatalf("encoded schema leaked raw schema content: %s", encoded)
	}
}

func TestFakeMergeNormalizeAndOutputContracts(t *testing.T) {
	extractOutput := ExtractArtifact[fakeArtifact]{LaneID: "generic-lane", ExtractorKey: "generic-extractor", SourceID: "source-1", ChunkID: "source-1:chunk:0", ChunkIndex: 0, Value: fakeArtifact{Value: "example"}}
	merger := fakeMerger{key: "generic-merger"}
	normalizer := fakeNormalizer{key: "generic-normalizer"}
	encoder := fakeOutputEncoder{key: "generic-output"}

	merged, err := merger.Merge(context.Background(), TypedMergeRequest[fakeArtifact]{
		LaneID:         "generic-lane",
		ExtractOutputs: []ExtractArtifact[fakeArtifact]{extractOutput},
	})
	if err != nil {
		t.Fatalf("Merge() error = %v, want nil", err)
	}
	if merger.Key() != "generic-merger" {
		t.Fatalf("Merger.Key() = %q, want generic-merger", merger.Key())
	}
	if merged.Value.Value != "example" {
		t.Fatalf("merged value = %q, want example", merged.Value.Value)
	}

	normalized, err := normalizer.Normalize(context.Background(), TypedNormalizeRequest[fakeArtifact]{
		LaneID:      "generic-lane",
		MergeOutput: MergeArtifact[fakeArtifact]{LaneID: "generic-lane", MergerKey: merger.Key(), SourceID: "source-1", Value: merged.Value},
	})
	if err != nil {
		t.Fatalf("Normalize() error = %v, want nil", err)
	}
	if normalizer.Key() != "generic-normalizer" {
		t.Fatalf("Normalizer.Key() = %q, want generic-normalizer", normalizer.Key())
	}
	if normalized.Value.Value != "example" {
		t.Fatalf("normalized value = %q, want example", normalized.Value.Value)
	}

	encoded, err := encoder.Encode(context.Background(), OutputRequest{
		Manifest:         artifacts.RunManifest{RunID: "run-1"},
		NormalizeOutputs: []SerializedOutput{{LaneID: "generic-lane", NormalizerKey: normalizer.Key(), SourceID: "source-1", Artifact: SerializedArtifact{Kind: "test/artifact", Schema: ArtifactSchema{ID: "schema-id", Name: "schema-name", Version: "v1"}, MediaType: "application/json", Content: []byte(`{"value":"example"}`)}}},
	})
	if err != nil {
		t.Fatalf("Encode() error = %v, want nil", err)
	}
	if encoder.Key() != "generic-output" {
		t.Fatalf("OutputEncoder.Key() = %q, want generic-output", encoder.Key())
	}
	if len(encoded.Files) != 1 {
		t.Fatalf("len(Files) = %d, want 1", len(encoded.Files))
	}
	if encoded.Files[0].ContentType != "application/json" {
		t.Fatalf("ContentType = %q, want application/json", encoded.Files[0].ContentType)
	}
	if string(encoded.Files[0].Bytes) != `{"run_id":"run-1","output_count":1}` {
		t.Fatalf("Bytes = %s, want encoded output", encoded.Files[0].Bytes)
	}
}

func TestOutputFileJSONShapeOmitsBytes(t *testing.T) {
	file := OutputFile{
		Name:        "artifacts/events.json",
		ContentType: "application/json",
		Bytes:       []byte(`{"ignored":true}`),
	}

	encoded, err := json.Marshal(file)
	if err != nil {
		t.Fatalf("json.Marshal() error = %v, want nil", err)
	}

	var got map[string]any
	if err := json.Unmarshal(encoded, &got); err != nil {
		t.Fatalf("json.Unmarshal() error = %v, want nil", err)
	}
	if got["name"] != "artifacts/events.json" {
		t.Fatalf("name = %#v, want logical file name", got["name"])
	}
	if got["content_type"] != "application/json" {
		t.Fatalf("content_type = %#v, want application/json", got["content_type"])
	}
	if _, ok := got["Bytes"]; ok {
		t.Fatalf("encoded output file leaked Bytes: %s", encoded)
	}
	if _, ok := got["bytes"]; ok {
		t.Fatalf("encoded output file leaked bytes: %s", encoded)
	}
}

type fakeAdapter struct {
	key string
	doc *source.SourceDocument
}

func (adapter fakeAdapter) Key() string {
	return adapter.key
}

func (adapter fakeAdapter) Parse(ctx context.Context, req ParseRequest) (*source.SourceDocument, error) {
	return adapter.doc, nil
}

type fakeChunker struct {
	key string
}

func (chunker fakeChunker) Key() string {
	return chunker.key
}

func (chunker fakeChunker) ReferenceSlots() []ReferenceSlot {
	return nil
}

func (chunker fakeChunker) Plan(ctx context.Context, req ChunkRequest) (ChunkPlanResult, error) {
	return ChunkPlanResult{
		Plan: source.ChunkPlan{
			SourceDigest: req.Source.Digest,
			Ranges: []source.ChunkRange{{
				StartUnitID: req.Source.Units[0].ID,
				EndUnitID:   req.Source.Units[len(req.Source.Units)-1].ID,
			}},
		},
	}, nil
}

type recordingChunker struct {
	key     string
	request ChunkRequest
}

func (chunker *recordingChunker) Key() string {
	return chunker.key
}

func (chunker *recordingChunker) ReferenceSlots() []ReferenceSlot {
	return nil
}

func (chunker *recordingChunker) Plan(ctx context.Context, req ChunkRequest) (ChunkPlanResult, error) {
	chunker.request = req
	return fakeChunker{key: chunker.key}.Plan(ctx, req)
}

type fakeExtractor struct {
	key string
}

type fakeArtifact struct{ Value string }

func (extractor fakeExtractor) Key() string {
	return extractor.key
}

func (extractor fakeExtractor) ReferenceSlots() []ReferenceSlot {
	return nil
}

func (extractor fakeExtractor) Extract(ctx context.Context, req TypedExtractionRequest) (TypedExtractionResult[fakeArtifact], error) {
	value := "example"
	if req.AmbientContext["mode"] == "chunked" {
		value = "chunked"
	}
	return TypedExtractionResult[fakeArtifact]{Value: fakeArtifact{Value: value}}, nil
}

type fakeMerger struct {
	key string
}

func (merger fakeMerger) Key() string {
	return merger.key
}

func (merger fakeMerger) Merge(ctx context.Context, req TypedMergeRequest[fakeArtifact]) (TypedMergeResult[fakeArtifact], error) {
	return TypedMergeResult[fakeArtifact]{Value: req.ExtractOutputs[0].Value}, nil
}

type fakeNormalizer struct {
	key string
}

func (normalizer fakeNormalizer) Key() string {
	return normalizer.key
}

func (normalizer fakeNormalizer) ReferenceSlots() []ReferenceSlot {
	return nil
}

func (normalizer fakeNormalizer) Normalize(ctx context.Context, req TypedNormalizeRequest[fakeArtifact]) (TypedNormalizeResult[fakeArtifact], error) {
	return TypedNormalizeResult[fakeArtifact]{Value: req.MergeOutput.Value}, nil
}

type fakeLLMClient struct{}

func (client fakeLLMClient) CompleteStructured(ctx context.Context, req StructuredCompletionRequest, out any) (StructuredCompletionResponse, error) {
	return StructuredCompletionResponse{
		Content: json.RawMessage(`{"value":"example"}`),
	}, nil
}

type fakeOutputEncoder struct {
	key string
}

func (encoder fakeOutputEncoder) Key() string {
	return encoder.key
}

func (encoder fakeOutputEncoder) Encode(ctx context.Context, req OutputRequest) (OutputResult, error) {
	return OutputResult{
		Files: []OutputFile{
			{
				Name:        "artifacts/generic.json",
				ContentType: "application/json",
				Bytes:       []byte(`{"run_id":"` + req.Manifest.RunID + `","output_count":1}`),
			},
		},
	}, nil
}