package json

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

	"gitea.maximumdirect.net/eric/notarius/internal/core/artifacts"
	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
	"gitea.maximumdirect.net/eric/notarius/internal/framework/pipeline"
)

func TestModuleSpecAndRegister(t *testing.T) {
	want := pipeline.ModuleSpec{
		Key:      Key,
		Stage:    pipeline.StageOutput,
		Requires: []string{"normalized"},
		Provides: []string{"encoded"},
	}
	if got := ModuleSpec(); !reflect.DeepEqual(got, want) {
		t.Fatalf("ModuleSpec() = %#v, want %#v", got, want)
	}

	registry := pipeline.NewOutputEncoderRegistry()
	if err := Register(registry); err != nil {
		t.Fatalf("Register() error = %v, want nil", err)
	}
	spec, ok := registry.Spec(Key)
	if !ok {
		t.Fatalf("Spec(%q) ok = false, want true", Key)
	}
	if !reflect.DeepEqual(spec, want) {
		t.Fatalf("registered spec = %#v, want %#v", spec, want)
	}
}

func TestEncodeReturnsLogicalFilesForNormalizedOutputs(t *testing.T) {
	req := contracts.OutputRequest{
		Manifest: artifacts.RunManifest{RunID: "run-1", PipelineID: "pipeline-1"},
		NormalizeOutputs: []contracts.NormalizeOutput{
			normalizeOutput("spells", `{"spell_casts":[{"spell":"Cure Wounds"}]}`),
			normalizeOutput("notes/items", `{"items":[{"name":"Torch"}]}`),
		},
		Rejected: []contracts.RejectedOutput{
			{
				Stage:         "extract",
				LaneID:        "spells",
				ModuleKey:     "dnd/spells",
				ChunkID:       "chunk-1",
				ChunkIndex:    1,
				ReasonCode:    "invalid",
				Message:       "not accepted",
				AttemptCount:  1,
				ValidatorName: "validator",
			},
		},
		Warnings: []contracts.Warning{{ReasonCode: "warning", Message: "check source"}},
	}

	result, err := New().Encode(context.Background(), req)
	if err != nil {
		t.Fatalf("Encode() error = %v, want nil", err)
	}

	wantNames := []string{
		"index.json",
		"lanes/notes_items.json",
		"lanes/spells.json",
		"manifest.json",
		"rejected.json",
		"warnings.json",
	}
	if got := outputFileNames(result.Files); !reflect.DeepEqual(got, wantNames) {
		t.Fatalf("file names = %#v, want %#v", got, wantNames)
	}

	for _, file := range result.Files {
		if !strings.HasSuffix(string(file.Bytes), "\n") {
			t.Fatalf("%s does not end with newline: %q", file.Name, string(file.Bytes))
		}
		if file.ContentType == contentTypeJSON && !stdjson.Valid(file.Bytes) {
			t.Fatalf("%s has invalid JSON: %s", file.Name, file.Bytes)
		}
	}

	spells := decodeObject(t, fileBytes(t, result.Files, "lanes/spells.json"))
	spellCasts := spells["spell_casts"].([]any)
	if spellCasts[0].(map[string]any)["spell"] != "Cure Wounds" {
		t.Fatalf("spells output = %#v, want raw normalized content", spells)
	}

	index := decodeObject(t, fileBytes(t, result.Files, "index.json"))
	outputFiles := index["output_files"].([]any)
	if len(outputFiles) != 2 {
		t.Fatalf("len(index output_files) = %d, want 2", len(outputFiles))
	}
	firstIndex := outputFiles[0].(map[string]any)
	secondIndex := outputFiles[1].(map[string]any)
	if firstIndex["lane_id"] != "notes/items" || secondIndex["lane_id"] != "spells" {
		t.Fatalf("output_files = %#v, want sorted by lane id", outputFiles)
	}

	rejected := decodeObject(t, fileBytes(t, result.Files, "rejected.json"))
	if got := rejected["rejected"].([]any); len(got) != 1 {
		t.Fatalf("rejected = %#v, want one rejected output", got)
	}
}

func TestEncodeIncludesRejectedAndWarningsWhenEmpty(t *testing.T) {
	result, err := New().Encode(context.Background(), contracts.OutputRequest{
		Manifest: artifacts.RunManifest{RunID: "run-1"},
	})
	if err != nil {
		t.Fatalf("Encode() error = %v, want nil", err)
	}

	rejected := decodeObject(t, fileBytes(t, result.Files, "rejected.json"))
	if got := rejected["rejected"].([]any); len(got) != 0 {
		t.Fatalf("rejected = %#v, want empty array", got)
	}
	warnings := decodeObject(t, fileBytes(t, result.Files, "warnings.json"))
	if got := warnings["warnings"].([]any); len(got) != 0 {
		t.Fatalf("warnings = %#v, want empty array", got)
	}
}

func TestEncodePrettyPrintsJSON(t *testing.T) {
	result, err := New().Encode(context.Background(), contracts.OutputRequest{
		Manifest: artifacts.RunManifest{RunID: "run-1"},
	})
	if err != nil {
		t.Fatalf("Encode() error = %v, want nil", err)
	}

	manifest := string(fileBytes(t, result.Files, "manifest.json"))
	if !strings.Contains(manifest, "\n  \"run_id\": \"run-1\"\n") {
		t.Fatalf("manifest JSON = %q, want two-space indentation", manifest)
	}
}

func TestEncodeIncludesManifestReferences(t *testing.T) {
	result, err := New().Encode(context.Background(), contracts.OutputRequest{
		Manifest: artifacts.RunManifest{
			RunID: "run-1",
			References: []artifacts.ReferenceProvenance{
				{
					Stage:         "extract",
					LaneID:        "events",
					SlotName:      "roster",
					OriginType:    "file",
					OriginURI:     "file:///tmp/roster.txt",
					Digest:        "sha256:reference",
					MediaType:     "text/plain; charset=utf-8",
					SizeBytes:     12,
					BindingSource: "config",
				},
			},
		},
	})
	if err != nil {
		t.Fatalf("Encode() error = %v, want nil", err)
	}

	manifest := decodeObject(t, fileBytes(t, result.Files, "manifest.json"))
	references := manifest["references"].([]any)
	if len(references) != 1 {
		t.Fatalf("references = %#v, want one entry", references)
	}
	reference := references[0].(map[string]any)
	if reference["lane_id"] != "events" || reference["slot_name"] != "roster" || reference["digest"] != "sha256:reference" {
		t.Fatalf("reference manifest = %#v, want lane slot digest", reference)
	}
	if _, ok := reference["content"]; ok {
		t.Fatalf("reference manifest = %#v, want no content field", reference)
	}
}

func TestEncodeIncludesManifestRawOutputProvenance(t *testing.T) {
	result, err := New().Encode(context.Background(), contracts.OutputRequest{
		Manifest: artifacts.RunManifest{
			RunID: "run-1",
			NormalizedOutputs: []artifacts.NormalizedOutputManifest{
				{
					LaneID:    "spells",
					ModuleKey: "noop",
					SourceID:  "source-1",
					MediaType: contentTypeJSON,
					Schema: artifacts.OutputSchemaProvenance{
						ID:      "schema-id",
						Name:    "schema-name",
						Version: "v1",
					},
				},
			},
			RejectedOutputs: []artifacts.RejectedOutputManifest{
				{
					Stage:        "extract",
					LaneID:       "spells",
					ModuleKey:    "dnd/spells",
					ChunkID:      "chunk-0",
					ReasonCode:   "raw_output_rejected",
					AttemptCount: 2,
				},
			},
		},
	})
	if err != nil {
		t.Fatalf("Encode() error = %v, want nil", err)
	}

	manifest := decodeObject(t, fileBytes(t, result.Files, "manifest.json"))
	normalized := manifest["normalized_outputs"].([]any)
	if len(normalized) != 1 {
		t.Fatalf("normalized_outputs = %#v, want one entry", normalized)
	}
	normalizedEntry := normalized[0].(map[string]any)
	if normalizedEntry["lane_id"] != "spells" || normalizedEntry["media_type"] != contentTypeJSON {
		t.Fatalf("normalized output manifest = %#v, want lane and media type", normalizedEntry)
	}
	rejected := manifest["rejected_outputs"].([]any)
	if len(rejected) != 1 {
		t.Fatalf("rejected_outputs = %#v, want one entry", rejected)
	}
	rejectedEntry := rejected[0].(map[string]any)
	if rejectedEntry["attempt_count"] != float64(2) || rejectedEntry["chunk_id"] != "chunk-0" {
		t.Fatalf("rejected output manifest = %#v, want attempt count and chunk", rejectedEntry)
	}
}

func TestEncodeRejectsLaneIDWithoutSafeFileName(t *testing.T) {
	_, err := New().Encode(context.Background(), contracts.OutputRequest{
		NormalizeOutputs: []contracts.NormalizeOutput{normalizeOutput("///", `{"value":true}`)},
	})
	if err == nil {
		t.Fatal("Encode() error = nil, want unsafe lane id error")
	}
	if !strings.Contains(err.Error(), "json output encoder") || !strings.Contains(err.Error(), "safe file name") {
		t.Fatalf("Encode() error = %q, want safe file name context", err.Error())
	}
}

func TestEncodeSanitizesParentPathSequences(t *testing.T) {
	result, err := New().Encode(context.Background(), contracts.OutputRequest{
		NormalizeOutputs: []contracts.NormalizeOutput{normalizeOutput("dnd..spell.", `{"value":true}`)},
	})
	if err != nil {
		t.Fatalf("Encode() error = %v, want nil", err)
	}

	if got := outputFileNames(result.Files); !containsString(got, "lanes/dnd__spell.json") {
		t.Fatalf("file names = %#v, want sanitized output filename", got)
	}
}

func TestEncodeRejectsInvalidJSONAndUnsupportedMediaTypes(t *testing.T) {
	tests := []struct {
		name   string
		output contracts.NormalizeOutput
		want   string
	}{
		{
			name:   "invalid JSON",
			output: normalizeOutput("spells", `{"spell_casts":[`),
			want:   "invalid JSON",
		},
		{
			name: "unsupported media type",
			output: func() contracts.NormalizeOutput {
				output := normalizeOutput("spells", `{"spell_casts":[]}`)
				output.Payload.MediaType = "text/plain"
				return output
			}(),
			want: "unsupported media type",
		},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			_, err := New().Encode(context.Background(), contracts.OutputRequest{
				NormalizeOutputs: []contracts.NormalizeOutput{test.output},
			})
			if err == nil {
				t.Fatal("Encode() error = nil, want error")
			}
			if !strings.Contains(err.Error(), test.want) {
				t.Fatalf("Encode() error = %q, want %q", err.Error(), test.want)
			}
		})
	}
}

func TestEncodeRejectsSanitizedFilenameCollisions(t *testing.T) {
	_, err := New().Encode(context.Background(), contracts.OutputRequest{
		NormalizeOutputs: []contracts.NormalizeOutput{
			normalizeOutput("a/b", `{"value":"slash"}`),
			normalizeOutput("a?b", `{"value":"question"}`),
		},
	})
	if err == nil {
		t.Fatal("Encode() error = nil, want duplicate file error")
	}
	if !strings.Contains(err.Error(), "duplicate output file") {
		t.Fatalf("Encode() error = %q, want duplicate file context", err.Error())
	}
}

func TestEncodeDoesNotMutateInputs(t *testing.T) {
	req := contracts.OutputRequest{
		Manifest: artifacts.RunManifest{RunID: "run-1"},
		NormalizeOutputs: []contracts.NormalizeOutput{
			normalizeOutput("spells", `{"name":"original"}`),
		},
		Rejected: []contracts.RejectedOutput{
			{Stage: "extract", LaneID: "spells", Message: "not accepted"},
		},
		Warnings: []contracts.Warning{{ReasonCode: "warning", Message: "message"}},
	}
	before := mustMarshal(t, req)

	result, err := New().Encode(context.Background(), req)
	if err != nil {
		t.Fatalf("Encode() error = %v, want nil", err)
	}
	after := mustMarshal(t, req)
	if before != after {
		t.Fatalf("request mutated:\nbefore: %s\nafter:  %s", before, after)
	}

	req.NormalizeOutputs[0].Payload.Content[0] = '['
	req.NormalizeOutputs[0].Payload.Metadata["name"] = "changed"
	req.Rejected[0].Message = "changed"
	req.Warnings[0].Message = "changed"

	if !stdjson.Valid(fileBytes(t, result.Files, "lanes/spells.json")) {
		t.Fatal("output changed after request mutation")
	}
	warnings := decodeObject(t, fileBytes(t, result.Files, "warnings.json"))
	gotWarnings := warnings["warnings"].([]any)
	if gotWarnings[0].(map[string]any)["message"] != "message" {
		t.Fatalf("warnings output changed after request mutation: %#v", gotWarnings)
	}
}

func TestOutputFilesDoNotContainWarnings(t *testing.T) {
	result, err := New().Encode(context.Background(), contracts.OutputRequest{
		NormalizeOutputs: []contracts.NormalizeOutput{normalizeOutput("spells", `{"spell":"Shield"}`)},
		Warnings: []contracts.Warning{
			{ReasonCode: "pipeline-warning", Message: "warning"},
		},
	})
	if err != nil {
		t.Fatalf("Encode() error = %v, want nil", err)
	}

	outputFile := decodeObject(t, fileBytes(t, result.Files, "lanes/spells.json"))
	if _, ok := outputFile["warnings"]; ok {
		t.Fatalf("output file contains warnings: %#v", outputFile)
	}
}

func normalizeOutput(laneID string, content string) contracts.NormalizeOutput {
	return contracts.NormalizeOutput{
		LaneID:        laneID,
		NormalizerKey: "noop",
		SourceID:      "source-1",
		Schema: contracts.ResponseSchema{
			ID:      "schema-id",
			Name:    "schema-name",
			Version: "v1",
		},
		Payload: contracts.RawPayload{
			Content:   []byte(content),
			MediaType: contentTypeJSON,
			Metadata:  map[string]any{"name": laneID},
		},
	}
}

func outputFileNames(files []contracts.OutputFile) []string {
	names := make([]string, 0, len(files))
	for _, file := range files {
		names = append(names, file.Name)
	}
	return names
}

func containsString(values []string, want string) bool {
	for _, value := range values {
		if value == want {
			return true
		}
	}
	return false
}

func fileBytes(t *testing.T, files []contracts.OutputFile, name string) []byte {
	t.Helper()
	for _, file := range files {
		if file.Name == name {
			return file.Bytes
		}
	}
	t.Fatalf("file %q not found in %#v", name, outputFileNames(files))
	return nil
}

func decodeObject(t *testing.T, data []byte) map[string]any {
	t.Helper()
	var got map[string]any
	if err := stdjson.Unmarshal(data, &got); err != nil {
		t.Fatalf("Unmarshal() error = %v, want nil\n%s", err, data)
	}
	return got
}

func mustMarshal(t *testing.T, value any) string {
	t.Helper()
	data, err := stdjson.Marshal(value)
	if err != nil {
		t.Fatalf("Marshal() error = %v, want nil", err)
	}
	return string(data)
}