package service_test

import (
	"context"
	"strings"
	"testing"

	"financeiro-carvalho/internal/model"
	"financeiro-carvalho/internal/service"
)

// mockImportRepo implements repository.TransactionRepository for import tests.
type mockImportRepo struct {
	catByDesc map[string]int // normalized desc → category_id
}

func (m *mockImportRepo) IsDuplicate(_ context.Context, _, _ string, _ float64) (bool, error) {
	return false, nil
}
func (m *mockImportRepo) IsExternalIDKnown(_ context.Context, _ string) (bool, error) {
	return false, nil
}
func (m *mockImportRepo) BulkInsert(_ context.Context, rows []model.ImportRow) (int, error) {
	return len(rows), nil
}
func (m *mockImportRepo) SaveImportLog(_ context.Context, _, _ string, _, _, _ int) error {
	return nil
}
func (m *mockImportRepo) CategoryByDescription(_ context.Context, descs []string) (map[string]int, error) {
	out := map[string]int{}
	for _, d := range descs {
		if id, ok := m.catByDesc[d]; ok {
			out[d] = id
		}
	}
	return out, nil
}

var csvMapping = model.CSVMapping{
	DateColumn:        0,
	AmountColumn:      1,
	DescriptionColumn: 2,
	DateFormat:        "02/01/2006",
	HasHeader:         false,
	DecimalSeparator:  ",",
	FieldSeparator:    ";",
}

func TestPreview_AutoCategorize(t *testing.T) {
	repo := &mockImportRepo{
		catByDesc: map[string]int{
			"padaria do ze": 3,
			"uber *trip":    7,
		},
	}
	svc := service.NewImportService(repo)

	csv := "01/03/2024;-45,00;PADARIA DO ZE\n02/03/2024;-22,50;UBER *TRIP\n03/03/2024;-99,00;LOJA NOVA XYZ\n"

	rows, _, err := svc.Preview(context.Background(), "fatura.csv", strings.NewReader(csv), &csvMapping)
	if err != nil {
		t.Fatalf("preview error: %v", err)
	}
	if len(rows) != 3 {
		t.Fatalf("expected 3 rows, got %d", len(rows))
	}

	// PADARIA DO ZE → category 3
	if rows[0].CategoryID == nil || *rows[0].CategoryID != 3 {
		t.Errorf("row[0] (PADARIA DO ZE) expected category 3, got %v", rows[0].CategoryID)
	}
	// UBER *TRIP → category 7
	if rows[1].CategoryID == nil || *rows[1].CategoryID != 7 {
		t.Errorf("row[1] (UBER *TRIP) expected category 7, got %v", rows[1].CategoryID)
	}
	// LOJA NOVA XYZ → no suggestion
	if rows[2].CategoryID != nil {
		t.Errorf("row[2] (LOJA NOVA XYZ) expected no category, got %v", rows[2].CategoryID)
	}
}

func TestPreview_DuplicateNotAutoCategorizated(t *testing.T) {
	// row that IS a duplicate should not get category pre-filled
	repo := &mockImportRepoDup{
		catByDesc: map[string]int{"padaria do ze": 3},
	}
	svc := service.NewImportService(repo)

	csv := "01/03/2024;-45,00;PADARIA DO ZE\n"

	rows, _, err := svc.Preview(context.Background(), "fatura.csv", strings.NewReader(csv), &csvMapping)
	if err != nil {
		t.Fatalf("preview error: %v", err)
	}
	if len(rows) != 1 {
		t.Fatalf("expected 1 row, got %d", len(rows))
	}
	if !rows[0].IsDuplicate {
		t.Error("expected row to be marked duplicate")
	}
	if rows[0].CategoryID != nil {
		t.Errorf("duplicate should not get category, got %v", rows[0].CategoryID)
	}
}

// mockImportRepoDup marks all rows as duplicate (by date+amount+desc).
type mockImportRepoDup struct {
	catByDesc map[string]int
}

func (m *mockImportRepoDup) IsDuplicate(_ context.Context, _, _ string, _ float64) (bool, error) {
	return true, nil // always duplicate
}
func (m *mockImportRepoDup) IsExternalIDKnown(_ context.Context, _ string) (bool, error) {
	return false, nil
}
func (m *mockImportRepoDup) BulkInsert(_ context.Context, rows []model.ImportRow) (int, error) {
	return len(rows), nil
}
func (m *mockImportRepoDup) SaveImportLog(_ context.Context, _, _ string, _, _, _ int) error {
	return nil
}
func (m *mockImportRepoDup) CategoryByDescription(_ context.Context, descs []string) (map[string]int, error) {
	out := map[string]int{}
	for _, d := range descs {
		if id, ok := m.catByDesc[d]; ok {
			out[d] = id
		}
	}
	return out, nil
}