package spells

import (
	"context"
	"encoding/json"
	"errors"
	"strings"
	"testing"

	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd/shared"
)

func TestExtractReturnsCanonicalOutputFromStructuredResponse(t *testing.T) {
	client := &fakeSpellsLLMClient{
		response: extractionResponse{
			SpellCasts: []spellCastResponse{
				{
					Caster:               " Aria ",
					Spell:                " Cure Wounds ",
					Effect:               " Heals an injured ally. ",
					NarrativeDescription: " Aria restores the fighter after the fight. ",
					SourceRefs:           responseSourceRefsInt("transcript", 1, 2),
				},
			},
		},
		content: []byte(`{"spell_casts":[{"caster":" Aria ","spell":" Cure Wounds ","effect":" Heals an injured ally. ","narrative_description":" Aria restores the fighter after the fight. ","source_refs":[{"source_id":"session-alpha","start_unit_id":1,"end_unit_id":2}]}],"raw_marker":true}`),
	}

	extractReq := extractionRequestWithClient(client)
	result, err := New().Extract(context.Background(), extractReq)
	if err != nil {
		t.Fatalf("Extract() error = %v, want nil", err)
	}

	if len(client.requests) != 1 {
		t.Fatalf("LLM calls = %d, want 1", len(client.requests))
	}
	llmReq := client.requests[0]
	if llmReq.StageName != Key {
		t.Fatalf("StageName = %q, want %q", llmReq.StageName, Key)
	}
	if llmReq.PromptID != PromptID || llmReq.PromptVersion != SchemaVersion {
		t.Fatalf("prompt = %q/%q, want %q/%q", llmReq.PromptID, llmReq.PromptVersion, PromptID, SchemaVersion)
	}
	if llmReq.SessionID != "session-123" || llmReq.ProfileID != "profile-spells" {
		t.Fatalf("session/profile = %q/%q, want session-123/profile-spells", llmReq.SessionID, llmReq.ProfileID)
	}
	transcript := llmReq.Inputs["transcript"]
	if transcript.Name != "transcript" || transcript.MediaType != "application/json" || transcript.Digest != "sha256:chunk" || transcript.OriginURI != "file:///session-alpha.json" {
		t.Fatalf("transcript metadata = %#v", transcript)
	}
	if got := string(transcript.Content); got != string(extractReq.Chunk.Content) {
		t.Fatalf("transcript content = %q, want chunk content %q", got, extractReq.Chunk.Content)
	}

	if result.Output.Payload.MediaType != "application/json" {
		t.Fatalf("MediaType = %q, want application/json", result.Output.Payload.MediaType)
	}
	if result.Output.Schema.ID != ResponseSchemaID || result.Output.Schema.Name != ResponseSchemaName || result.Output.Schema.Version != SchemaVersion {
		t.Fatalf("schema = %#v, want response schema provenance", result.Output.Schema)
	}
	if !json.Valid(result.Output.Schema.JSONSchema) {
		t.Fatalf("schema JSON is invalid or missing: %s", result.Output.Schema.JSONSchema)
	}
	if strings.Contains(string(result.Output.Payload.Content), "raw_marker") {
		t.Fatalf("content = %q, want canonical payload without raw completion marker", result.Output.Payload.Content)
	}

	var payload extractionResponse
	if err := json.Unmarshal(result.Output.Payload.Content, &payload); err != nil {
		t.Fatalf("Unmarshal(Content) error = %v, want nil", err)
	}
	if len(payload.SpellCasts) != 1 || payload.SpellCasts[0].Spell != " Cure Wounds " {
		t.Fatalf("payload = %#v, want structured response fields", payload)
	}
	if got := payload.SpellCasts[0].SourceRefs[0].SourceID; got != "session-alpha" {
		t.Fatalf("source_id = %q, want canonical source document ID", got)
	}
}

func TestExtractorManifestMetadataIncludesPromptAndSchemaProvenance(t *testing.T) {
	metadata := New().ManifestMetadata()

	tests := map[string]string{
		"prompt_id":               PromptID,
		"prompt_version":          SchemaVersion,
		"response_schema_key":     string(ResponseSchemaKey),
		"response_schema_id":      ResponseSchemaID,
		"response_schema_name":    ResponseSchemaName,
		"response_schema_version": SchemaVersion,
	}
	for key, want := range tests {
		if metadata[key] != want {
			t.Fatalf("metadata[%q] = %#v, want %q", key, metadata[key], want)
		}
	}
	for _, key := range []string{"prompt_sha256", "response_schema_sha256"} {
		value, ok := metadata[key].(string)
		if !ok || !strings.HasPrefix(value, "sha256:") {
			t.Fatalf("metadata[%q] = %#v, want sha256 value", key, metadata[key])
		}
	}
}

func TestExtractPassesReferencesAsPromptInputs(t *testing.T) {
	client := &fakeSpellsLLMClient{response: extractionResponse{SpellCasts: []spellCastResponse{}}}
	req := extractionRequestWithClient(client)
	req.References = contracts.ReferenceSet{
		Slots: map[string]contracts.ResolvedReferenceSlot{
			"players": {
				Slot: contracts.ReferenceSlot{Name: "players"},
				Items: []contracts.ReferenceItem{
					{SlotName: "players", Content: []byte("Alice: Aria Brightmantle")},
				},
			},
			"party": {
				Slot: contracts.ReferenceSlot{Name: "party"},
				Items: []contracts.ReferenceItem{
					{SlotName: "party", Content: []byte("Aria Brightmantle: party cleric")},
				},
			},
			"glossary": {
				Slot: contracts.ReferenceSlot{Name: "glossary"},
				Items: []contracts.ReferenceItem{
					{SlotName: "glossary", Content: []byte("Brightmantle: local temple name")},
				},
			},
		},
	}

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

	if len(client.requests) != 1 {
		t.Fatalf("LLM calls = %d, want 1", len(client.requests))
	}
	request := client.requests[0]
	if request.PromptID != PromptID || request.PromptVersion != SchemaVersion {
		t.Fatalf("prompt = %q/%q, want %q/%q", request.PromptID, request.PromptVersion, PromptID, SchemaVersion)
	}
	if got := string(request.Inputs["players"].Content); got != "Alice: Aria Brightmantle" {
		t.Fatalf("players input = %q, want reference content", got)
	}
	if got := string(request.Inputs["party"].Content); got != "Aria Brightmantle: party cleric" {
		t.Fatalf("party input = %q, want reference content", got)
	}
	if got := string(request.Inputs["glossary"].Content); got != "Brightmantle: local temple name" {
		t.Fatalf("glossary input = %q, want reference content", got)
	}
	if strings.Contains(string(request.Inputs["transcript"].Content), "Aria Brightmantle: party cleric") {
		t.Fatalf("transcript input contains reference content")
	}
}

func TestPromptInputsMapLegacyRosterReferenceToParty(t *testing.T) {
	inputs := shared.PromptInputs(spellSourceInput(), contracts.ReferenceSet{
		Slots: map[string]contracts.ResolvedReferenceSlot{
			"roster": {
				Slot: contracts.ReferenceSlot{Name: "roster"},
				Items: []contracts.ReferenceItem{
					{SlotName: "roster", Content: []byte("Legacy roster text")},
				},
			},
		},
	})

	if got := string(inputs["party"].Content); got != "Legacy roster text" {
		t.Fatalf("party input = %q, want legacy roster content", got)
	}
	if _, ok := inputs["roster"]; ok {
		t.Fatalf("roster prompt input was present; want only party input")
	}
}

func TestExtractReturnsRawOutputForEmptyResponse(t *testing.T) {
	client := &fakeSpellsLLMClient{response: extractionResponse{SpellCasts: []spellCastResponse{}}}

	result, err := New().Extract(context.Background(), extractionRequestWithClient(client))
	if err != nil {
		t.Fatalf("Extract() error = %v, want nil", err)
	}
	var payload extractionResponse
	if err := json.Unmarshal(result.Output.Payload.Content, &payload); err != nil {
		t.Fatalf("Unmarshal(Content) error = %v, want nil", err)
	}
	if len(payload.SpellCasts) != 0 {
		t.Fatalf("SpellCasts = %#v, want none", payload.SpellCasts)
	}
}

func TestExtractReturnsCanonicalOutputForMalformedStructuredResponse(t *testing.T) {
	client := &fakeSpellsLLMClient{response: extractionResponse{}}

	result, err := New().Extract(context.Background(), extractionRequestWithClient(client))
	if err != nil {
		t.Fatalf("Extract() error = %v, want nil", err)
	}
	if string(result.Output.Payload.Content) != `{"spell_casts":null}` {
		t.Fatalf("content = %s, want canonical structured output", result.Output.Payload.Content)
	}
}

func TestExtractWrapsLLMClientError(t *testing.T) {
	client := &fakeSpellsLLMClient{err: errors.New("provider unavailable")}

	_, err := New().Extract(context.Background(), extractionRequestWithClient(client))
	if err == nil {
		t.Fatal("Extract() error = nil, want LLM error")
	}
	if !strings.Contains(err.Error(), "dnd spells") || !strings.Contains(err.Error(), "provider unavailable") {
		t.Fatalf("Extract() error = %q, want wrapped LLM context", err.Error())
	}
}

func TestExtractRejectsInvalidRequests(t *testing.T) {
	validClient := &fakeSpellsLLMClient{response: extractionResponse{SpellCasts: []spellCastResponse{}}}
	validReq := extractionRequestWithClient(validClient)
	canceledCtx, cancel := context.WithCancel(context.Background())
	cancel()

	tests := []struct {
		name      string
		extractor *Extractor
		ctx       context.Context
		req       contracts.ExtractionRequest
		want      string
	}{
		{name: "nil extractor", extractor: nil, ctx: context.Background(), req: validReq, want: "extractor"},
		{name: "nil context", extractor: New(), ctx: nil, req: validReq, want: "context"},
		{name: "canceled context", extractor: New(), ctx: canceledCtx, req: validReq, want: "context"},
		{name: "nil source", extractor: New(), ctx: context.Background(), req: contracts.ExtractionRequest{Chunk: validReq.Chunk, LLMClient: validReq.LLMClient}, want: "source"},
		{name: "nil chunk", extractor: New(), ctx: context.Background(), req: contracts.ExtractionRequest{Source: validReq.Source, LLMClient: validReq.LLMClient}, want: "chunk"},
		{name: "empty chunk units", extractor: New(), ctx: context.Background(), req: emptyChunkRequest(validReq), want: "units"},
		{name: "nil LLM client", extractor: New(), ctx: context.Background(), req: contracts.ExtractionRequest{Source: validReq.Source, Chunk: validReq.Chunk}, want: "LLM client"},
		{name: "source input mismatches chunk", extractor: New(), ctx: context.Background(), req: mismatchedSourceInputRequest(validReq), want: "must match chunk"},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			_, err := tt.extractor.Extract(tt.ctx, tt.req)
			if err == nil {
				t.Fatal("Extract() error = nil, want error")
			}
			if !strings.Contains(err.Error(), "dnd spells") || !strings.Contains(err.Error(), tt.want) {
				t.Fatalf("Extract() error = %q, want %q context", err.Error(), tt.want)
			}
		})
	}
}

func TestExtractOrdersSpellCastsByEarliestSourceUnit(t *testing.T) {
	client := &fakeSpellsLLMClient{
		response: extractionResponse{
			SpellCasts: []spellCastResponse{
				{
					Caster:               "Bandit Shaman",
					Spell:                "Fire Bolt",
					Effect:               "Burns.",
					NarrativeDescription: "Second spell.",
					SourceRefs:           responseSourceRefs("session-alpha", 2, 2),
				},
				{
					Caster:               "Aria",
					Spell:                "Cure Wounds",
					Effect:               "Heals.",
					NarrativeDescription: "First spell.",
					SourceRefs:           responseSourceRefs("session-alpha", 1, 1),
				},
				{
					Caster:               "Narrator",
					Spell:                "Unknown Spell",
					Effect:               "No cited range.",
					NarrativeDescription: "This should sort after cited spell casts.",
				},
			},
		},
	}

	result, err := New().Extract(context.Background(), extractionRequestWithClient(client))
	if err != nil {
		t.Fatalf("Extract() error = %v, want nil", err)
	}
	var payload extractionResponse
	if err := json.Unmarshal(result.Output.Payload.Content, &payload); err != nil {
		t.Fatalf("Unmarshal(Content) error = %v, want nil", err)
	}
	if len(payload.SpellCasts) != 3 ||
		payload.SpellCasts[0].Spell != "Cure Wounds" ||
		payload.SpellCasts[1].Spell != "Fire Bolt" ||
		payload.SpellCasts[2].Spell != "Unknown Spell" {
		t.Fatalf("spell order = %#v, want earliest source-unit order with uncited spell last", payload.SpellCasts)
	}
}

func TestExtractCanonicalizesSourceRefs(t *testing.T) {
	client := &fakeSpellsLLMClient{
		response: extractionResponse{
			SpellCasts: []spellCastResponse{
				{
					Caster:               "Aria",
					Spell:                "Cure Wounds",
					Effect:               "Heals.",
					NarrativeDescription: "Aria heals.",
					SourceRefs: []shared.SourceRefResponse{
						{SourceID: "gameplay_transcript", StartUnitID: shared.UnitRefFromInt(2), EndUnitID: shared.UnitRefFromInt(2)},
						{SourceID: "", StartUnitID: shared.UnitRefFromInt(1), EndUnitID: shared.UnitRefFromInt(2)},
						{SourceID: "transcript", StartUnitID: shared.UnitRefFromInt(1), EndUnitID: shared.UnitRefFromInt(2)},
					},
				},
			},
		},
	}

	result, err := New().Extract(context.Background(), extractionRequestWithClient(client))
	if err != nil {
		t.Fatalf("Extract() error = %v, want nil", err)
	}
	var payload extractionResponse
	if err := json.Unmarshal(result.Output.Payload.Content, &payload); err != nil {
		t.Fatalf("Unmarshal(Content) error = %v, want nil", err)
	}
	refs := payload.SpellCasts[0].SourceRefs
	if len(refs) != 2 {
		t.Fatalf("source refs = %#v, want duplicate collapsed", refs)
	}
	for _, ref := range refs {
		if ref.SourceID != "session-alpha" {
			t.Fatalf("source ref = %#v, want canonical source_id", ref)
		}
	}
	if refs[0].StartUnitID.Int() != 1 || refs[0].EndUnitID.Int() != 2 ||
		refs[1].StartUnitID.Int() != 2 || refs[1].EndUnitID.Int() != 2 {
		t.Fatalf("source refs = %#v, want sorted unit ranges", refs)
	}
}

func TestExtractPreservesInvalidSourceRefsForValidators(t *testing.T) {
	client := &fakeSpellsLLMClient{
		response: extractionResponse{
			SpellCasts: []spellCastResponse{
				{
					Caster:               "Aria",
					Spell:                "Cure Wounds",
					Effect:               "Heals.",
					NarrativeDescription: "Aria heals.",
					SourceRefs: []shared.SourceRefResponse{
						{SourceID: "transcript", StartUnitID: shared.UnitRefFromInt(99), EndUnitID: shared.UnitRefFromString("missing")},
					},
				},
			},
		},
	}

	result, err := New().Extract(context.Background(), extractionRequestWithClient(client))
	if err != nil {
		t.Fatalf("Extract() error = %v, want nil", err)
	}
	var payload map[string][]map[string]any
	if err := json.Unmarshal(result.Output.Payload.Content, &payload); err != nil {
		t.Fatalf("Unmarshal(Content) error = %v, want nil", err)
	}
	ref := payload["spell_casts"][0]["source_refs"].([]any)[0].(map[string]any)
	if ref["source_id"] != "session-alpha" || ref["start_unit_id"] != float64(99) || ref["end_unit_id"] != "" {
		t.Fatalf("source ref = %#v, want source_id canonicalized without unit repair", ref)
	}
}

func TestExtractDefensivelyCopiesRawContent(t *testing.T) {
	client := &fakeSpellsLLMClient{
		response: extractionResponse{
			SpellCasts: []spellCastResponse{
				{
					Caster:               "Aria",
					Spell:                "Cure Wounds",
					Effect:               "Heals.",
					NarrativeDescription: "Aria heals.",
					SourceRefs:           responseSourceRefs("session-alpha", 1, 2),
				},
			},
		},
	}

	result, err := New().Extract(context.Background(), extractionRequestWithClient(client))
	if err != nil {
		t.Fatalf("Extract() error = %v, want nil", err)
	}
	client.response.SpellCasts[0].SourceRefs[0].StartUnitID = shared.UnitRefFromInt(99)

	var payload extractionResponse
	if err := json.Unmarshal(result.Output.Payload.Content, &payload); err != nil {
		t.Fatalf("Unmarshal(Content) error = %v, want nil", err)
	}
	if got := payload.SpellCasts[0].SourceRefs[0].StartUnitID.String(); got != "1" {
		t.Fatalf("source ref start = %q, want copied 1", got)
	}
}

func extractionRequestWithClient(client contracts.StructuredLLMClient) contracts.ExtractionRequest {
	req := promptExtractionRequest()
	req.LLMClient = client
	req.SourceInput = spellChunkInput(req.Chunk)
	req.SessionID = "session-123"
	req.LLMProfile = "profile-spells"
	return req
}

const spellTranscriptJSON = `{"id":"session-alpha","segments":[{"id":1,"text":"Aria raises her hand and casts Cure Wounds."}]}`

func spellSourceInput() contracts.LLMInputMaterial {
	return contracts.NewLLMInputMaterial("source", "application/json", []byte(spellTranscriptJSON), "sha256:transcript", "file:///session-alpha.json")
}

func spellChunkInput(chunk *contracts.SourceChunk) contracts.LLMInputMaterial {
	return contracts.NewLLMInputMaterial("source", chunk.MediaType, chunk.Content, "sha256:chunk", "file:///session-alpha.json")
}

func emptyChunkRequest(req contracts.ExtractionRequest) contracts.ExtractionRequest {
	req.Chunk = &contracts.SourceChunk{
		ID:       req.Chunk.ID,
		SourceID: req.Chunk.SourceID,
		Index:    req.Chunk.Index,
	}
	return req
}

func mismatchedSourceInputRequest(req contracts.ExtractionRequest) contracts.ExtractionRequest {
	req.SourceInput = spellSourceInput()
	return req
}

type fakeSpellsLLMClient struct {
	response extractionResponse
	content  []byte
	err      error
	requests []contracts.StructuredCompletionRequest
}

func (client *fakeSpellsLLMClient) CompleteStructured(ctx context.Context, req contracts.StructuredCompletionRequest, out any) (contracts.StructuredCompletionResponse, error) {
	client.requests = append(client.requests, cloneStructuredCompletionRequest(req))
	if client.err != nil {
		return contracts.StructuredCompletionResponse{}, client.err
	}

	target, ok := out.(*extractionResponse)
	if !ok {
		return contracts.StructuredCompletionResponse{}, errors.New("unexpected output target")
	}
	*target = client.response
	content := append([]byte(nil), client.content...)
	if len(content) == 0 {
		var err error
		content, err = json.Marshal(client.response)
		if err != nil {
			return contracts.StructuredCompletionResponse{}, err
		}
	}
	return contracts.StructuredCompletionResponse{Content: content}, nil
}

func cloneStructuredCompletionRequest(req contracts.StructuredCompletionRequest) contracts.StructuredCompletionRequest {
	req.Inputs = req.Inputs.Clone()
	req.Vars = cloneVars(req.Vars)
	return req
}

func cloneVars(in map[string]any) map[string]any {
	if len(in) == 0 {
		return nil
	}
	out := make(map[string]any, len(in))
	for key, value := range in {
		out[key] = value
	}
	return out
}