package npcs

import (
	"context"
	"reflect"
	"strings"
	"testing"

	"gitea.maximumdirect.net/eric/notarius/internal/core/source"
	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
	"gitea.maximumdirect.net/eric/notarius/internal/framework/pipeline"
	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd"
	identity "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/npcs/identity"
)

func TestModuleContractAndIdentity(t *testing.T) {
	if _, err := DecodeOptions(nil); err != nil {
		t.Fatalf("DecodeOptions(nil) error = %v, want nil", err)
	}
	if _, err := DecodeOptions(map[string]any{"unexpected": true}); err == nil || !strings.Contains(err.Error(), "unknown option") {
		t.Fatalf("DecodeOptions() error = %v, want unknown option error", err)
	}

	want := pipeline.ModuleSpec{
		Key:          Key,
		Stage:        pipeline.StageNormalize,
		Requires:     []string{"merged"},
		Provides:     []string{"normalized"},
		ArtifactKind: dnd.NPCListKind,
	}
	if got := ModuleSpec(); !reflect.DeepEqual(got, want) {
		t.Fatalf("ModuleSpec() = %#v, want %#v", got, want)
	}
	if slots := New(Options{}).ReferenceSlots(); slots != nil {
		t.Fatalf("ReferenceSlots() = %#v, want nil", slots)
	}

	registry := pipeline.NewNormalizerRegistry()
	if err := Register(registry); err != nil {
		t.Fatalf("Register() error = %v, want nil", err)
	}
	if registered, ok := registry.SpecForArtifact(Key, dnd.NPCListKind); !ok || !reflect.DeepEqual(registered, want) {
		t.Fatalf("registered spec = %#v, ok = %t, want %#v", registered, ok, want)
	}
	if err := Register(nil); err == nil || !strings.Contains(err.Error(), "normalizer registry") {
		t.Fatalf("Register(nil) error = %v, want registry error", err)
	}

	normalizer := New(Options{})
	metadata := normalizer.ManifestMetadata()
	if metadata["identity_policy"] != identity.Policy || metadata["normalization_policy"] != normalizationPolicy {
		t.Fatalf("metadata = %#v, want identity and normalization policies", metadata)
	}
	fingerprints := normalizer.CheckpointFingerprints()
	wantFingerprints := []pipeline.CheckpointFingerprint{
		{Name: "identity_policy", Value: identity.Policy},
		{Name: "normalization_policy", Value: normalizationPolicy},
	}
	if !reflect.DeepEqual(fingerprints, wantFingerprints) {
		t.Fatalf("fingerprints = %#v, want %#v", fingerprints, wantFingerprints)
	}
	fingerprints[0].Value = "changed"
	if got := normalizer.CheckpointFingerprints(); !reflect.DeepEqual(got, wantFingerprints) {
		t.Fatalf("fingerprints were not defensive: %#v", got)
	}
}

func TestNormalizePerRecordFieldsAndEvidence(t *testing.T) {
	input := dnd.NPCList{NPCs: []dnd.NPC{{
		ID:          "wrong",
		Name:        "  Lady\tAsh  ",
		Aliases:     []string{" Ash ", "  L.A. ", "l.a.", "  Lady Ash  "},
		Description: "  first description\n",
		Relationships: []dnd.NPCRelationship{
			{Target: "  Lord\nOak ", Relationship: " friend "},
			{Target: "lord oak", Relationship: "friend"},
		},
		SourceRefs: []source.SourceRef{
			{SourceID: "b", StartUnitID: 2, EndUnitID: 3},
			{SourceID: "a", StartUnitID: 4, EndUnitID: 4},
			{SourceID: "b", StartUnitID: 2, EndUnitID: 3},
		},
	}}}

	result, err := New(Options{}).Normalize(context.Background(), normalizeRequest(input))
	if err != nil {
		t.Fatalf("Normalize() error = %v, want nil", err)
	}
	got := result.Value.NPCs[0]
	if got.Name != "Lady Ash" || got.Description != "first description" {
		t.Fatalf("normalized fields = %#v, want normalized display and description", got)
	}
	if !reflect.DeepEqual(got.Aliases, []string{"Ash", "L.A."}) {
		t.Fatalf("aliases = %#v, want canonical alias removal and deduplication", got.Aliases)
	}
	wantRelationships := []dnd.NPCRelationship{{Target: "Lord Oak", Relationship: "friend"}}
	if !reflect.DeepEqual(got.Relationships, wantRelationships) {
		t.Fatalf("relationships = %#v, want %#v", got.Relationships, wantRelationships)
	}
	wantRefs := []source.SourceRef{
		{SourceID: "a", StartUnitID: 4, EndUnitID: 4},
		{SourceID: "b", StartUnitID: 2, EndUnitID: 3},
	}
	if !reflect.DeepEqual(got.SourceRefs, wantRefs) {
		t.Fatalf("source refs = %#v, want %#v", got.SourceRefs, wantRefs)
	}
	if got.ID != identity.DeriveID("Lady Ash") {
		t.Fatalf("ID = %q, want derived ID", got.ID)
	}
	if !hasWarning(result.Warnings, ReasonCodeNPCFieldsNormalized, "npcs[0]") ||
		!hasWarning(result.Warnings, ReasonCodeSourceReferencesNormalized, "npcs[0]") ||
		!hasWarning(result.Warnings, ReasonCodeNPCIDRecomputed, "npcs[0]") {
		t.Fatalf("warnings = %#v, want field, source, and ID warnings", result.Warnings)
	}
}

func TestNormalizeConsolidatesIdentityComponentsInStableOrder(t *testing.T) {
	input := dnd.NPCList{NPCs: []dnd.NPC{
		{
			Name:          " Captain Vale ",
			Description:   "first description",
			Aliases:       []string{"Vale"},
			Relationships: []dnd.NPCRelationship{{Target: "Archivist", Relationship: "knows"}},
			SourceRefs:    []source.SourceRef{{SourceID: "a", StartUnitID: 1, EndUnitID: 1}},
		},
		{
			Name:        "Captain Vale",
			Description: "second description",
			Aliases:     []string{"CV"},
			SourceRefs:  []source.SourceRef{{SourceID: "b", StartUnitID: 1, EndUnitID: 1}},
		},
		{
			Name:        "The Sage",
			Description: "sage description",
			Aliases:     []string{"Archivist"},
			SourceRefs:  []source.SourceRef{{SourceID: "c", StartUnitID: 1, EndUnitID: 1}},
		},
		{
			Name:        "Archivist",
			Description: "later sage description",
			Aliases:     []string{"Chronicler"},
			SourceRefs:  []source.SourceRef{{SourceID: "d", StartUnitID: 1, EndUnitID: 1}},
		},
		{
			Name:        "North",
			Description: "north description",
			SourceRefs:  []source.SourceRef{{SourceID: "e", StartUnitID: 1, EndUnitID: 1}},
		},
		{
			Name:        "North Old",
			Description: "old north description",
			Aliases:     []string{"North"},
			SourceRefs:  []source.SourceRef{{SourceID: "f", StartUnitID: 1, EndUnitID: 1}},
		},
		{
			Name:        "North Renamed",
			Description: "renamed north description",
			Aliases:     []string{"North Old"},
			SourceRefs:  []source.SourceRef{{SourceID: "g", StartUnitID: 1, EndUnitID: 1}},
		},
		{Name: "Red", Description: "red", Aliases: []string{"Shared"}, SourceRefs: []source.SourceRef{{SourceID: "h", StartUnitID: 1, EndUnitID: 1}}},
		{Name: "Blue", Description: "blue", Aliases: []string{"Shared"}, SourceRefs: []source.SourceRef{{SourceID: "i", StartUnitID: 1, EndUnitID: 1}}},
	}}

	result, err := New(Options{}).Normalize(context.Background(), normalizeRequest(input))
	if err != nil {
		t.Fatalf("Normalize() error = %v, want nil", err)
	}
	if got := len(result.Value.NPCs); got != 5 {
		t.Fatalf("normalized NPC count = %d, want five components", got)
	}

	first := result.Value.NPCs[0]
	if first.Name != "Captain Vale" || first.Description != "first description" || !reflect.DeepEqual(first.Aliases, []string{"Vale", "CV"}) {
		t.Fatalf("first component = %#v, want first description and ordered aliases", first)
	}
	if !reflect.DeepEqual(first.SourceRefs, []source.SourceRef{
		{SourceID: "a", StartUnitID: 1, EndUnitID: 1},
		{SourceID: "b", StartUnitID: 1, EndUnitID: 1},
	}) {
		t.Fatalf("first provenance = %#v, want unioned refs", first.SourceRefs)
	}

	second := result.Value.NPCs[1]
	if second.Name != "The Sage" || !reflect.DeepEqual(second.Aliases, []string{"Archivist", "Chronicler"}) || second.Description != "sage description" {
		t.Fatalf("canonical-to-alias component = %#v, want consolidated sage", second)
	}
	if first.Relationships[0].Target != "The Sage" {
		t.Fatalf("relationship target = %q, want The Sage", first.Relationships[0].Target)
	}
	if !hasWarning(result.Warnings, ReasonCodeRelationshipTargetCanonicalized, "npcs[0]") ||
		!hasWarning(result.Warnings, ReasonCodeDuplicateNPCCollapsed, "npcs[0]") ||
		!hasWarning(result.Warnings, ReasonCodeDuplicateNPCCollapsed, "npcs[2]") {
		t.Fatalf("warnings = %#v, want collapse and target warnings", result.Warnings)
	}

	if got := result.Value.NPCs[2].Aliases; !reflect.DeepEqual(got, []string{"North Old", "North Renamed"}) {
		t.Fatalf("transitive aliases = %#v, want ordered canonical members", got)
	}
	if result.Value.NPCs[3].Name != "Red" || result.Value.NPCs[4].Name != "Blue" {
		t.Fatalf("shared-alias ordering = %#v, want Red then Blue", result.Value.NPCs[3:])
	}
}

func TestNormalizePreservesInvalidEvidenceAndDoesNotAliasInput(t *testing.T) {
	invalid := dnd.NPCList{NPCs: []dnd.NPC{{
		Name:          " ",
		Aliases:       []string{""},
		Description:   " ",
		Relationships: []dnd.NPCRelationship{{Target: " ", Relationship: " "}},
		SourceRefs:    []source.SourceRef{{SourceID: "source", StartUnitID: 9, EndUnitID: 9}},
	}}}
	original := cloneNPCListForTest(invalid)
	result, err := New(Options{}).Normalize(context.Background(), normalizeRequest(invalid))
	if err != nil {
		t.Fatalf("Normalize() error = %v, want nil", err)
	}
	if !reflect.DeepEqual(invalid, original) {
		t.Fatalf("normalizer mutated input: got %#v, want %#v", invalid, original)
	}
	if result.Value.NPCs[0].Name != "" || result.Value.NPCs[0].Aliases[0] != "" || result.Value.NPCs[0].Relationships[0].Target != "" {
		t.Fatalf("invalid evidence was unexpectedly removed: %#v", result.Value.NPCs[0])
	}

	result.Value.NPCs[0].Aliases[0] = "changed"
	result.Value.NPCs[0].Relationships[0].Target = "changed"
	result.Value.NPCs[0].SourceRefs[0].SourceID = "changed"
	if invalid.NPCs[0].Aliases[0] != "" || invalid.NPCs[0].Relationships[0].Target != " " || invalid.NPCs[0].SourceRefs[0].SourceID != "source" {
		t.Fatalf("output aliases input storage: input = %#v", invalid)
	}
}

func TestNormalizeHandlesNilAndCanceledCalls(t *testing.T) {
	normalizer := New(Options{})
	result, err := normalizer.Normalize(context.Background(), normalizeRequest(dnd.NPCList{NPCs: nil}))
	if err != nil || result.Value.NPCs != nil {
		t.Fatalf("nil list result = %#v, error = %v, want nil NPC slice", result.Value, err)
	}
	canceled, cancel := context.WithCancel(context.Background())
	cancel()
	if _, err := normalizer.Normalize(canceled, normalizeRequest(dnd.NPCList{})); err == nil || !strings.Contains(err.Error(), "context error") {
		t.Fatalf("canceled Normalize() error = %v, want context error", err)
	}
	if _, err := normalizer.Normalize(nil, normalizeRequest(dnd.NPCList{})); err == nil || !strings.Contains(err.Error(), "context must not be nil") {
		t.Fatalf("nil context Normalize() error = %v, want context error", err)
	}
	var nilNormalizer *Normalizer
	if _, err := nilNormalizer.Normalize(context.Background(), normalizeRequest(dnd.NPCList{})); err == nil {
		t.Fatal("nil normalizer Normalize() error = nil, want error")
	}
}

func TestNormalizePreservesPresentEmptyAliases(t *testing.T) {
	result, err := New(Options{}).Normalize(context.Background(), normalizeRequest(dnd.NPCList{NPCs: []dnd.NPC{{
		Name:        "Hooded Guard",
		Aliases:     []string{},
		Description: "A distinguishable sentry.",
		SourceRefs:  []source.SourceRef{{SourceID: "session", StartUnitID: 1, EndUnitID: 1}},
	}}}))
	if err != nil {
		t.Fatalf("Normalize() error = %v, want nil", err)
	}
	if result.Value.NPCs[0].Aliases == nil || len(result.Value.NPCs[0].Aliases) != 0 {
		t.Fatalf("aliases = %#v, want present empty array", result.Value.NPCs[0].Aliases)
	}
}

func normalizeRequest(value dnd.NPCList) contracts.TypedNormalizeRequest[dnd.NPCList] {
	return contracts.TypedNormalizeRequest[dnd.NPCList]{
		MergeOutput: contracts.MergeArtifact[dnd.NPCList]{Value: value},
	}
}

func cloneNPCListForTest(input dnd.NPCList) dnd.NPCList {
	output := dnd.NPCList{}
	if input.NPCs != nil {
		output.NPCs = make([]dnd.NPC, len(input.NPCs))
		for index, npc := range input.NPCs {
			output.NPCs[index] = cloneNPC(npc)
		}
	}
	return output
}

func hasWarning(warnings []contracts.Warning, reason, scope string) bool {
	for _, warning := range warnings {
		if warning.ReasonCode == reason && warning.Scope == scope {
			return true
		}
	}
	return false
}