package json

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

	"gitea.maximumdirect.net/eric/notarius/internal/core/artifacts"
	"gitea.maximumdirect.net/eric/notarius/internal/core/source"
	"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 TestEncodeReturnsLogicalFilesGroupedByArtifactType(t *testing.T) {
	req := contracts.OutputRequest{
		Manifest: artifacts.RunManifest{RunID: "run-1", PipelineID: "pipeline-1"},
		Approved: []artifacts.Artifact{
			artifact("dnd.spell-cast", "first"),
			artifact("notes/item", "item"),
			artifact("dnd.spell-cast", "second"),
		},
		Rejected: []artifacts.RejectedArtifact{
			{
				Candidate:     candidate("bad type", "bad"),
				ValidatorName: "validator",
				ReasonCode:    "invalid",
				Message:       "not accepted",
			},
		},
		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{
		"artifacts/dnd.spell-cast.json",
		"artifacts/notes_item.json",
		"index.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 file.ContentType != contentTypeJSON {
			t.Fatalf("%s ContentType = %q, want %q", file.Name, file.ContentType, contentTypeJSON)
		}
		if !strings.HasSuffix(string(file.Bytes), "\n") {
			t.Fatalf("%s does not end with newline: %q", file.Name, string(file.Bytes))
		}
		if !stdjson.Valid(file.Bytes) {
			t.Fatalf("%s has invalid JSON: %s", file.Name, file.Bytes)
		}
	}

	spellFile := decodeObject(t, fileBytes(t, result.Files, "artifacts/dnd.spell-cast.json"))
	if spellFile["artifact_type"] != "dnd.spell-cast" {
		t.Fatalf("artifact_type = %#v, want dnd.spell-cast", spellFile["artifact_type"])
	}
	spells := spellFile["artifacts"].([]any)
	if len(spells) != 2 {
		t.Fatalf("len(spells) = %d, want 2", len(spells))
	}
	firstPayload := spells[0].(map[string]any)["payload"].(map[string]any)
	secondPayload := spells[1].(map[string]any)["payload"].(map[string]any)
	if firstPayload["name"] != "first" || secondPayload["name"] != "second" {
		t.Fatalf("spell order payloads = %#v then %#v, want runner order", firstPayload, secondPayload)
	}

	index := decodeObject(t, fileBytes(t, result.Files, "index.json"))
	artifactFiles := index["artifact_files"].([]any)
	if len(artifactFiles) != 2 {
		t.Fatalf("len(index artifact_files) = %d, want 2", len(artifactFiles))
	}
	firstIndex := artifactFiles[0].(map[string]any)
	secondIndex := artifactFiles[1].(map[string]any)
	if firstIndex["artifact_type"] != "dnd.spell-cast" || secondIndex["artifact_type"] != "notes/item" {
		t.Fatalf("artifact_files = %#v, want sorted by artifact type", artifactFiles)
	}
}

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 TestEncodeRejectsArtifactTypeWithoutSafeFileName(t *testing.T) {
	_, err := New().Encode(context.Background(), contracts.OutputRequest{
		Approved: []artifacts.Artifact{artifact("///", "unsafe")},
	})
	if err == nil {
		t.Fatal("Encode() error = nil, want unsafe artifact type 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{
		Approved: []artifacts.Artifact{artifact("dnd..spell.", "spell")},
	})
	if err != nil {
		t.Fatalf("Encode() error = %v, want nil", err)
	}

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

func TestEncodeRejectsSanitizedFilenameCollisions(t *testing.T) {
	_, err := New().Encode(context.Background(), contracts.OutputRequest{
		Approved: []artifacts.Artifact{
			artifact("a/b", "slash"),
			artifact("a?b", "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"},
		Approved: []artifacts.Artifact{
			artifact("dnd.spell", "original"),
		},
		Rejected: []artifacts.RejectedArtifact{
			{
				Candidate:     candidate("bad", "rejected"),
				ValidatorName: "validator",
				ReasonCode:    "invalid",
				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.Approved[0].Payload[0] = '['
	req.Approved[0].SourceRefs[0].StartUnitID = "changed"
	req.Approved[0].Metadata["name"] = "changed"
	req.Rejected[0].Candidate.Payload[0] = '['
	req.Warnings[0].Message = "changed"

	if !stdjson.Valid(fileBytes(t, result.Files, "artifacts/dnd.spell.json")) {
		t.Fatal("artifact 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 TestArtifactFilesDoNotContainWarnings(t *testing.T) {
	result, err := New().Encode(context.Background(), contracts.OutputRequest{
		Approved: []artifacts.Artifact{artifact("dnd.spell", "spell")},
		Warnings: []contracts.Warning{
			{ReasonCode: "pipeline-warning", Message: "warning"},
		},
	})
	if err != nil {
		t.Fatalf("Encode() error = %v, want nil", err)
	}

	artifactFile := decodeObject(t, fileBytes(t, result.Files, "artifacts/dnd.spell.json"))
	if _, ok := artifactFile["warnings"]; ok {
		t.Fatalf("artifact file contains warnings: %#v", artifactFile)
	}
}

func artifact(artifactType, name string) artifacts.Artifact {
	return artifacts.Artifact{
		ExtractorKey:  "extractor",
		ArtifactType:  artifactType,
		SchemaVersion: "v1",
		Payload:       stdjson.RawMessage(`{"name":"` + name + `"}`),
		SourceRefs: []source.SourceRef{
			{SourceID: "source-1", StartUnitID: "u1", EndUnitID: "u1"},
		},
		Metadata: map[string]any{"name": name},
	}
}

func candidate(artifactType, name string) artifacts.ArtifactCandidate {
	return artifacts.ArtifactCandidate{
		Index:         1,
		ExtractorKey:  "extractor",
		ArtifactType:  artifactType,
		SchemaVersion: "v1",
		Payload:       stdjson.RawMessage(`{"name":"` + name + `"}`),
		SourceRefs: []source.SourceRef{
			{SourceID: "source-1", StartUnitID: "u1", EndUnitID: "u1"},
		},
		Metadata: map[string]any{"name": name},
	}
}

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)
}