package main

import (
	"bytes"
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"sync"
	"testing"
	"time"

	"github.com/gin-gonic/gin"
)

// mockHandleChatLLM mocks LLM behavior for integration tests
// It implements only the public interface methods.
type mockHandleChatLLM struct {
	keywordsResp map[string]interface{}
	disambigID   string
	keywordsErr  error
	disambigErr  error
	embeddings   []float64
	embeddingErr error
}

func (m *mockHandleChatLLM) ExtractKeywords(ctx context.Context, msg string) (map[string]interface{}, error) {
	return m.keywordsResp, m.keywordsErr
}
func (m *mockHandleChatLLM) DisambiguateBestMatch(ctx context.Context, msg string, candidates []Visit) (string, error) {
	return m.disambigID, m.disambigErr
}
func (m *mockHandleChatLLM) GetEmbeddings(ctx context.Context, input string) ([]float64, error) {
	return m.embeddings, m.embeddingErr
}
func (m *mockHandleChatLLM) TranslateToEnglish(ctx context.Context, msg string) (string, error) {
	return msg, nil
}

// mapChatRepo is an in-memory implementation of ChatRepositoryAPI for tests.
type mapChatRepo struct {
	mu           sync.Mutex
	interactions []ChatInteraction
	rawEvents    []struct{ CorrelationID, Phase, Raw string }
}

func (r *mapChatRepo) SaveChatInteraction(ctx context.Context, rec ChatInteraction) error {
	r.mu.Lock()
	defer r.mu.Unlock()
	r.interactions = append(r.interactions, rec)
	return nil
}
func (r *mapChatRepo) ListChatInteractions(ctx context.Context, limit, offset int) ([]ChatInteraction, error) {
	r.mu.Lock()
	defer r.mu.Unlock()
	if offset >= len(r.interactions) {
		return []ChatInteraction{}, nil
	}
	end := offset + limit
	if end > len(r.interactions) {
		end = len(r.interactions)
	}
	// return a copy slice to avoid mutation
	out := make([]ChatInteraction, end-offset)
	copy(out, r.interactions[offset:end])
	return out, nil
}
func (r *mapChatRepo) SaveLLMRawEvent(ctx context.Context, correlationID, phase, raw string) error {
	r.mu.Lock()
	defer r.mu.Unlock()
	r.rawEvents = append(r.rawEvents, struct{ CorrelationID, Phase, Raw string }{correlationID, phase, raw})
	return nil
}
func (r *mapChatRepo) ListLLMRawEvents(ctx context.Context, correlationID string, limit, offset int) ([]RawLLMEvent, error) {
	r.mu.Lock()
	defer r.mu.Unlock()
	var out []RawLLMEvent
	for _, e := range r.rawEvents {
		if e.CorrelationID == correlationID {
			out = append(out, RawLLMEvent{CorrelationID: e.CorrelationID, Phase: e.Phase, RawJSON: e.Raw, CreatedAt: time.Now()})
		}
	}
	return out, nil
}
func (r *mapChatRepo) CountUsers(ctx context.Context) (int, error) { return 0, nil }
func (r *mapChatRepo) CreateUser(ctx context.Context, username, passwordHash string) error {
	return nil
}
func (r *mapChatRepo) GetUserByUsername(ctx context.Context, username string) (*User, error) {
	return nil, nil
}
func (r *mapChatRepo) SaveKnowledgeModel(ctx context.Context, text string) error { return nil }
func (r *mapChatRepo) ListKnowledgeModels(ctx context.Context, limit, offset int) ([]knowledgeModelMeta, error) {
	return nil, nil
}
func (r *mapChatRepo) GetKnowledgeModelText(ctx context.Context, id int64) (string, error) {
	return "", nil
}

// testVisitDB2 replicates a minimal VisitDB for integration
// (avoids relying on real Bleve index)
type testVisitDB2 struct {
	byID       map[string]Visit
	candidates []Visit
	findErr    error
}

func (db *testVisitDB2) FindCandidates(keywords []string) ([]Visit, error) {
	return db.candidates, db.findErr
}
func (db *testVisitDB2) FindById(id string) (Visit, error) {
	if v, ok := db.byID[id]; ok {
		return v, nil
	}
	return Visit{}, context.DeadlineExceeded
}

func TestHandleChat_PersistsSuccessInteraction(t *testing.T) {
	gin.SetMode(gin.TestMode)
	visit := Visit{ID: "xray", Notes: "Exam note", Procedures: []Procedure{{Name: "Röntgen vizsgálat", Price: 16000, DurationMin: 25}}}
	db := &testVisitDB2{byID: map[string]Visit{"xray": visit}, candidates: []Visit{visit}}
	llm := &mockHandleChatLLM{keywordsResp: map[string]interface{}{"translate": "xray leg", "animal": "dog", "keyword": []string{"xray", "bone"}}, disambigID: "xray"}
	repo := &mapChatRepo{}
	cs := NewChatService(llm, db, repo)
	r := gin.New()
	r.POST("/chat", cs.HandleChat)

	body := map[string]string{"message": "my dog needs an x-ray"}
	b, _ := json.Marshal(body)
	req, _ := http.NewRequest(http.MethodPost, "/chat", bytes.NewReader(b))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()
	r.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200 got %d", w.Code)
	}
	corrID := w.Header().Get("X-Correlation-ID")
	if corrID == "" {
		t.Fatalf("expected correlation id header set")
	}

	repo.mu.Lock()
	if len(repo.interactions) != 1 {
		repo.mu.Unlock()
		bdy := w.Body.String()
		t.Fatalf("expected 1 interaction persisted, got %d; body=%s", len(repo.interactions), bdy)
	}
	rec := repo.interactions[0]
	repo.mu.Unlock()
	if rec.CorrelationID != corrID {
		t.Errorf("correlation mismatch: header=%s rec=%s", corrID, rec.CorrelationID)
	}
	if rec.BestVisitID != "xray" {
		t.Errorf("expected BestVisitID xray got %s", rec.BestVisitID)
	}
	if rec.TotalPrice != 16000 || rec.TotalDuration != 25 {
		t.Errorf("unexpected totals: %+v", rec)
	}
	if len(rec.Keywords) != 2 {
		t.Errorf("expected 2 keywords got %v", rec.Keywords)
	}
}

func TestHandleChat_PersistsOnLLMError(t *testing.T) {
	gin.SetMode(gin.TestMode)
	llm := &mockHandleChatLLM{keywordsErr: context.DeadlineExceeded}
	db := &testVisitDB2{byID: map[string]Visit{}, candidates: []Visit{}}
	repo := &mapChatRepo{}
	cs := NewChatService(llm, db, repo)
	r := gin.New()
	r.POST("/chat", cs.HandleChat)

	body := map[string]string{"message": "some message"}
	b, _ := json.Marshal(body)
	req, _ := http.NewRequest(http.MethodPost, "/chat", bytes.NewReader(b))
	req.Header.Set("Content-Type", "application/json")
	w := httptest.NewRecorder()
	r.ServeHTTP(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200 got %d", w.Code)
	}

	repo.mu.Lock()
	cnt := len(repo.interactions)
	var rec ChatInteraction
	if cnt == 1 {
		rec = repo.interactions[0]
	}
	repo.mu.Unlock()
	if cnt != 1 {
		t.Fatalf("expected 1 interaction persisted on error got %d", cnt)
	}
	if rec.BestVisitID != "" {
		t.Errorf("expected no best visit on error got %s", rec.BestVisitID)
	}
	cid := w.Header().Get("X-Correlation-ID")
	if cid == "" {
		t.Fatalf("expected correlation id header on error path")
	}
}