package enemyevents

import (
	"crypto/sha256"
	"encoding/hex"
	"strings"
	"testing"

	"gitea.maximumdirect.net/eric/notarius/internal/core/source"
	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd"
	combatturncodec "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/codec/combatturns"
	occurrencecodec "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/codec/npcoccurrences"
	npccodec "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/codec/npcregistry"
	scenecodec "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/codec/scenedescriptions"
	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/npcs/identity"
	sceneregistry "gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/scenedescriptions/registry"
)

func TestReferenceSlotsDescribeRequiredTypedArtifacts(t *testing.T) {
	slots := referenceSlots()
	if len(slots) != 8 {
		t.Fatalf("ReferenceSlots() count = %d, want 8", len(slots))
	}
	byName := make(map[string]contracts.ReferenceSlot, len(slots))
	for index, slot := range slots {
		if index > 0 && slots[index-1].Name > slot.Name {
			t.Fatalf("ReferenceSlots() is not sorted: %#v", slots)
		}
		byName[slot.Name] = slot
	}
	for _, want := range []struct {
		name string
		kind contracts.ArtifactKind
	}{
		{NPCRegistryReferenceSlot, dnd.NPCRegistryKind},
		{SceneDescriptionReferenceSlot, dnd.SceneDescriptionListKind},
		{CombatTurnReferenceSlot, dnd.CombatTurnListKind},
		{NPCOccurrenceReferenceSlot, dnd.NPCOccurrenceListKind},
	} {
		slot, ok := byName[want.name]
		if !ok || !slot.Required || slot.MaxBytes != ReferenceMaxBytes || len(slot.AcceptedMediaTypes) != 1 || slot.AcceptedMediaTypes[0] != "application/json" || len(slot.AcceptedArtifactKinds) != 1 || slot.AcceptedArtifactKinds[0] != want.kind {
			t.Fatalf("slot %q = %#v", want.name, slot)
		}
	}

	slots[0].AcceptedMediaTypes[0] = "changed"
	if referenceSlots()[0].AcceptedMediaTypes[0] == "changed" {
		t.Fatal("ReferenceSlots() returned caller-owned storage")
	}
}

func TestGroundingProducesExactSourceFreePromptInputs(t *testing.T) {
	resolver, err := newGroundingResolver(groundingReferences(t, "Ashfang", dnd.SceneKindCombat))
	if err != nil {
		t.Fatal(err)
	}
	resolved, err := resolver.Resolve(contracts.ReferenceSet{})
	if err != nil {
		t.Fatal(err)
	}
	inputs := resolved.PromptInputs()
	want := map[string]string{
		NPCRegistryReferenceSlot:   `{"npcs":[{"name":"Ashfang"}]}`,
		CombatTurnReferenceSlot:    `{"combat_turns":[{"actor":"Ashfang","turn_kind":"turn"},{"actor":"Aria","turn_kind":"reaction"}]}`,
		NPCOccurrenceReferenceSlot: `{"npc_occurrences":[{"name":"Ashfang","kind":"combat_opponent"}]}`,
	}
	if len(inputs) != len(want) {
		t.Fatalf("PromptInputs() = %#v", inputs)
	}
	for name, content := range want {
		input, ok := inputs[name]
		if !ok || string(input.Content) != content || input.Digest != digest([]byte(content)) || input.OriginURI != "" || input.MediaType != "application/json" {
			t.Fatalf("PromptInputs()[%q] = %#v, want %q", name, input, content)
		}
		for _, forbidden := range []string{"source_ref", "npc-ashfang", "origin", "summary", "combat-session"} {
			if strings.Contains(string(input.Content), forbidden) {
				t.Fatalf("PromptInputs()[%q] leaked %q: %s", name, forbidden, input.Content)
			}
		}
	}
	if _, ok := inputs[SceneDescriptionReferenceSlot]; ok {
		t.Fatal("scene descriptions were rendered as prompt grounding")
	}

	inputs[CombatTurnReferenceSlot] = contracts.NewLLMInputMaterial("changed", "text/plain", []byte("changed"), "", "")
	if next := resolved.PromptInputs()[CombatTurnReferenceSlot]; string(next.Content) != want[CombatTurnReferenceSlot] {
		t.Fatal("PromptInputs() did not return a defensive copy")
	}
}

func TestGroundingResolvesGeneratedReferencesAndSceneEligibility(t *testing.T) {
	prepared := groundingReferences(t, "Ashfang", dnd.SceneKindCombat)
	resolver, err := newGroundingResolver(prepared)
	if err != nil {
		t.Fatal(err)
	}

	generated := groundingReferences(t, "Grimjaw", dnd.SceneKindNarrative)
	resolved, err := resolver.Resolve(generated)
	if err != nil {
		t.Fatal(err)
	}
	if got := string(resolved.PromptInputs()[NPCRegistryReferenceSlot].Content); got != `{"npcs":[{"name":"Grimjaw"}]}` {
		t.Fatalf("generated NPC projection = %s", got)
	}
	match, err := resolver.SceneMatch(generated, combatChunk())
	if err != nil {
		t.Fatal(err)
	}
	if match != (sceneregistry.ChunkMatch{State: sceneregistry.MatchExact, Kind: dnd.SceneKindNarrative}) {
		t.Fatalf("generated scene match = %#v", match)
	}
	match, err = resolver.SceneMatch(generated, &source.Chunk{ID: "other", Ref: combatChunk().Ref})
	if err != nil {
		t.Fatal(err)
	}
	if match.State != sceneregistry.MatchMissing {
		t.Fatal("missing scene was not reported")
	}
	mismatched := combatChunk()
	mismatched.Ref.EndUnitID++
	match, err = resolver.SceneMatch(generated, mismatched)
	if err != nil {
		t.Fatal(err)
	}
	if match.State != sceneregistry.MatchMismatched {
		t.Fatal("mismatched scene was not reported")
	}

	static, err := resolver.Resolve(contracts.ReferenceSet{})
	if err != nil {
		t.Fatal(err)
	}
	if got := string(static.PromptInputs()[NPCRegistryReferenceSlot].Content); got != `{"npcs":[{"name":"Ashfang"}]}` {
		t.Fatalf("static NPC projection changed after generated resolution: %s", got)
	}
	match, err = resolver.SceneMatch(contracts.ReferenceSet{}, combatChunk())
	if err != nil {
		t.Fatal(err)
	}
	if match != (sceneregistry.ChunkMatch{State: sceneregistry.MatchExact, Kind: dnd.SceneKindCombat}) {
		t.Fatalf("static scene match = %#v", match)
	}
}

func TestGroundingRejectsMissingAndInvalidReferences(t *testing.T) {
	valid := groundingReferences(t, "Ashfang", dnd.SceneKindCombat)
	for _, test := range []struct {
		slot string
		want string
	}{
		{NPCRegistryReferenceSlot, "NPC registry"},
		{SceneDescriptionReferenceSlot, "scene descriptions"},
		{CombatTurnReferenceSlot, CombatTurnReferenceSlot},
		{NPCOccurrenceReferenceSlot, NPCOccurrenceReferenceSlot},
	} {
		t.Run("missing "+test.slot, func(t *testing.T) {
			resolver, err := newGroundingResolver(withoutSlot(valid, test.slot))
			if err != nil {
				t.Fatal(err)
			}
			if test.slot == SceneDescriptionReferenceSlot {
				_, err = resolver.SceneMatch(contracts.ReferenceSet{}, combatChunk())
			} else {
				_, err = resolver.Resolve(contracts.ReferenceSet{})
			}
			if err == nil || !strings.Contains(err.Error(), test.want) {
				t.Fatalf("grounding error = %v, want missing %q reference", err, test.slot)
			}
		})
	}

	tests := []struct {
		name string
		set  contracts.ReferenceSet
	}{
		{"multiple items", replaceSlot(valid, CombatTurnReferenceSlot, contracts.ResolvedReferenceSlot{Items: []contracts.ReferenceItem{{MediaType: "application/json"}, {MediaType: "application/json"}}})},
		{"malformed durable content", replaceItem(valid, NPCOccurrenceReferenceSlot, contracts.ReferenceItem{MediaType: "application/json", Content: []byte(`{}`)})},
		{"wrong media type", replaceItem(valid, CombatTurnReferenceSlot, contracts.ReferenceItem{MediaType: "text/plain", Content: valid.Slots[CombatTurnReferenceSlot].Items[0].Content})},
		{"oversize", replaceItem(valid, CombatTurnReferenceSlot, contracts.ReferenceItem{MediaType: "application/json", Content: make([]byte, ReferenceMaxBytes+1)})},
	}
	resolver, err := newGroundingResolver(valid)
	if err != nil {
		t.Fatal(err)
	}
	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			if _, err := resolver.Resolve(test.set); err == nil {
				t.Fatal("Resolve() error = nil")
			}
		})
	}
}

func groundingReferences(t *testing.T, enemy string, sceneKind dnd.SceneKind) contracts.ReferenceSet {
	t.Helper()
	npcContent, err := npccodec.New().Encode(dnd.NPCRegistry{NPCs: []dnd.NPC{{
		ID:         identity.DeriveID(enemy),
		Name:       enemy,
		SourceRefs: []source.SourceRef{{SourceID: "combat-session", StartUnitID: 1, EndUnitID: 1}},
	}}})
	if err != nil {
		t.Fatal(err)
	}
	sceneContent, err := scenecodec.New().Encode(dnd.SceneDescriptionList{Scenes: []dnd.SceneDescription{{
		ID:        "combat-scene",
		SourceRef: source.SourceRef{SourceID: "combat-session", StartUnitID: 1, EndUnitID: 4},
		Kind:      sceneKind,
		Title:     "Combat session",
		Summary:   "A detailed scene summary that must not reach the prompt.",
	}}})
	if err != nil {
		t.Fatal(err)
	}
	turnContent, err := combatturncodec.New().Encode(dnd.CombatTurnList{CombatTurns: []dnd.CombatTurn{
		{Actor: enemy, TurnKind: dnd.CombatTurnKindTurn, SourceRefs: []source.SourceRef{{SourceID: "combat-session", StartUnitID: 1, EndUnitID: 1}}},
		{Actor: "Aria", TurnKind: dnd.CombatTurnKindReaction, SourceRefs: []source.SourceRef{{SourceID: "combat-session", StartUnitID: 2, EndUnitID: 2}}},
	}})
	if err != nil {
		t.Fatal(err)
	}
	occurrenceContent, err := occurrencecodec.New().Encode(dnd.NPCOccurrenceList{Occurrences: []dnd.NPCOccurrence{
		{NPCID: identity.DeriveID(enemy), Name: enemy, Kind: dnd.NPCOccurrenceKindCombatOpponent, SourceRefs: []source.SourceRef{{SourceID: "combat-session", StartUnitID: 1, EndUnitID: 1}}},
		{NPCID: identity.DeriveID("Aria"), Name: "Aria", Kind: dnd.NPCOccurrenceKindCombatAlly, SourceRefs: []source.SourceRef{{SourceID: "combat-session", StartUnitID: 2, EndUnitID: 2}}},
	}})
	if err != nil {
		t.Fatal(err)
	}
	return contracts.ReferenceSet{Slots: map[string]contracts.ResolvedReferenceSlot{
		NPCRegistryReferenceSlot:      {Items: []contracts.ReferenceItem{newReferenceItem(NPCRegistryReferenceSlot, npcContent)}},
		SceneDescriptionReferenceSlot: {Items: []contracts.ReferenceItem{newReferenceItem(SceneDescriptionReferenceSlot, sceneContent)}},
		CombatTurnReferenceSlot:       {Items: []contracts.ReferenceItem{newReferenceItem(CombatTurnReferenceSlot, turnContent)}},
		NPCOccurrenceReferenceSlot:    {Items: []contracts.ReferenceItem{newReferenceItem(NPCOccurrenceReferenceSlot, occurrenceContent)}},
	}}
}

func newReferenceItem(slot string, content []byte) contracts.ReferenceItem {
	return contracts.ReferenceItem{
		SlotName:  slot,
		MediaType: "application/json",
		Content:   append([]byte(nil), content...),
		Digest:    digest(content),
		Origin:    contracts.ReferenceOrigin{Type: "file", URI: "file:///private/reference.json"},
		Producer:  contracts.ReferenceProducer{PipelineID: "prior", StepID: "extract", LaneID: "lane", ModuleKey: "dnd/example"},
	}
}

func withoutSlot(set contracts.ReferenceSet, name string) contracts.ReferenceSet {
	cloned := contracts.ReferenceSet{Slots: make(map[string]contracts.ResolvedReferenceSlot, len(set.Slots)-1)}
	for slotName, slot := range set.Slots {
		if slotName != name {
			cloned.Slots[slotName] = slot
		}
	}
	return cloned
}

func replaceSlot(set contracts.ReferenceSet, name string, value contracts.ResolvedReferenceSlot) contracts.ReferenceSet {
	cloned := contracts.ReferenceSet{Slots: make(map[string]contracts.ResolvedReferenceSlot, len(set.Slots))}
	for slotName, slot := range set.Slots {
		cloned.Slots[slotName] = slot
	}
	cloned.Slots[name] = value
	return cloned
}

func replaceItem(set contracts.ReferenceSet, name string, item contracts.ReferenceItem) contracts.ReferenceSet {
	return replaceSlot(set, name, contracts.ResolvedReferenceSlot{Items: []contracts.ReferenceItem{item}})
}

func combatChunk() *source.Chunk {
	return &source.Chunk{ID: "combat-scene", Ref: source.SourceRef{SourceID: "combat-session", StartUnitID: 1, EndUnitID: 4}}
}

func digest(content []byte) string {
	sum := sha256.Sum256(content)
	return "sha256:" + hex.EncodeToString(sum[:])
}