package service

import (
	"context"
	"errors"
	"testing"

	"wucher/internal/domain/medicine"
)

type medicineRepoMock struct {
	createCalled  bool
	updateCalled  bool
	deleteCalled  bool
	getByIDCalled bool
	listCalled    bool

	lastCreate     *medicine.Medicine
	lastUpdate     *medicine.Medicine
	lastDeleteID   []byte
	lastDeleteBy   []byte
	lastGetByID    []byte
	lastListFilter string
	lastListSort   string
	lastListLimit  int
	lastListOffset int

	getByIDResult *medicine.Medicine
	listResult    []medicine.Medicine
	listTotal     int64

	createErr  error
	updateErr  error
	deleteErr  error
	getByIDErr error
	listErr    error
}

func (m *medicineRepoMock) Create(_ context.Context, row *medicine.Medicine) error {
	m.createCalled = true
	m.lastCreate = row
	return m.createErr
}

func (m *medicineRepoMock) Update(_ context.Context, row *medicine.Medicine) error {
	m.updateCalled = true
	m.lastUpdate = row
	return m.updateErr
}

func (m *medicineRepoMock) Delete(_ context.Context, id []byte, deletedBy []byte) error {
	m.deleteCalled = true
	m.lastDeleteID = id
	m.lastDeleteBy = deletedBy
	return m.deleteErr
}

func (m *medicineRepoMock) GetByID(_ context.Context, id []byte) (*medicine.Medicine, error) {
	m.getByIDCalled = true
	m.lastGetByID = id
	return m.getByIDResult, m.getByIDErr
}

func (m *medicineRepoMock) List(_ context.Context, filter, sort string, limit, offset int) ([]medicine.Medicine, int64, error) {
	m.listCalled = true
	m.lastListFilter = filter
	m.lastListSort = sort
	m.lastListLimit = limit
	m.lastListOffset = offset
	return m.listResult, m.listTotal, m.listErr
}

func TestNewMedicineService(t *testing.T) {
	repo := &medicineRepoMock{}
	svc := NewMedicineService(repo)
	if svc == nil || svc.repo == nil {
		t.Fatalf("expected service and repo initialized")
	}
}

func TestMedicineServiceCreate(t *testing.T) {
	repo := &medicineRepoMock{}
	svc := NewMedicineService(repo)
	row := &medicine.Medicine{Name: "Paracetamol", Pack:"500mg", Column: 1}

	if err := svc.Create(context.Background(), row); err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if !repo.createCalled || repo.lastCreate != row {
		t.Fatalf("expected Create forwarded to repo")
	}

	repo.createErr = errors.New("create failed")
	if err := svc.Create(context.Background(), row); err == nil {
		t.Fatalf("expected error from repo")
	}
}

func TestMedicineServiceUpdate(t *testing.T) {
	repo := &medicineRepoMock{}
	svc := NewMedicineService(repo)
	row := &medicine.Medicine{Name: "Paracetamol", Pack:"500mg", Column: 1}

	if err := svc.Update(context.Background(), row); err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if !repo.updateCalled || repo.lastUpdate != row {
		t.Fatalf("expected Update forwarded to repo")
	}

	repo.updateErr = errors.New("update failed")
	if err := svc.Update(context.Background(), row); err == nil {
		t.Fatalf("expected error from repo")
	}
}

func TestMedicineServiceDelete(t *testing.T) {
	repo := &medicineRepoMock{}
	svc := NewMedicineService(repo)
	id := []byte("id")
	deletedBy := []byte("by")

	if err := svc.Delete(context.Background(), id, deletedBy); err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if !repo.deleteCalled {
		t.Fatalf("expected Delete forwarded to repo")
	}
	if string(repo.lastDeleteID) != string(id) || string(repo.lastDeleteBy) != string(deletedBy) {
		t.Fatalf("expected delete params forwarded")
	}

	repo.deleteErr = errors.New("delete failed")
	if err := svc.Delete(context.Background(), id, deletedBy); err == nil {
		t.Fatalf("expected error from repo")
	}
}

func TestMedicineServiceGetByID(t *testing.T) {
	expected := &medicine.Medicine{Name: "Paracetamol", Pack:"500mg", Column: 1}
	repo := &medicineRepoMock{getByIDResult: expected}
	svc := NewMedicineService(repo)
	id := []byte("id")

	got, err := svc.GetByID(context.Background(), id)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if got != expected {
		t.Fatalf("unexpected result")
	}
	if !repo.getByIDCalled || string(repo.lastGetByID) != string(id) {
		t.Fatalf("expected GetByID forwarded")
	}

	repo.getByIDErr = errors.New("get failed")
	if _, err := svc.GetByID(context.Background(), id); err == nil {
		t.Fatalf("expected error from repo")
	}
}

func TestMedicineServiceList(t *testing.T) {
	repo := &medicineRepoMock{
		listResult: []medicine.Medicine{{Name: "Paracetamol", Pack:"500mg", Column: 1}},
		listTotal:  1,
	}
	svc := NewMedicineService(repo)

	rows, total, err := svc.List(context.Background(), "find", "column", 10, 20)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if len(rows) != 1 || total != 1 {
		t.Fatalf("unexpected list result")
	}
	if !repo.listCalled {
		t.Fatalf("expected List forwarded to repo")
	}
	if repo.lastListFilter != "find" || repo.lastListSort != "`column` ASC" || repo.lastListLimit != 10 || repo.lastListOffset != 20 {
		t.Fatalf("unexpected list args forwarded")
	}

	rows, total, err = svc.List(context.Background(), "find", "name", 10, 20)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if len(rows) != 1 || total != 1 {
		t.Fatalf("unexpected list result")
	}
	if repo.lastListSort != "name ASC" {
		t.Fatalf("unexpected name sort args forwarded: %q", repo.lastListSort)
	}

	repo.listErr = errors.New("list failed")
	if _, _, err := svc.List(context.Background(), "", "unknown", 1, 0); err == nil {
		t.Fatalf("expected error from repo")
	}
}

func TestNormalizeMedicineSort(t *testing.T) {
	cases := map[string]string{
		"name":        "name ASC",
		"-name":       "name DESC",
		"note":        "COALESCE(NULLIF(note, ''), pack) ASC",
		"-note":       "COALESCE(NULLIF(note, ''), pack) DESC",
		"pack":        "pack ASC",
		"-pack":       "pack DESC",
		"unit":        "unit ASC",
		"-unit":       "unit DESC",
		"column":      "`column` ASC",
		"-column":     "`column` DESC",
		"is_active":   "is_active ASC",
		"-is_active":  "is_active DESC",
		"created_at":  "created_at ASC",
		"-created_at": "created_at DESC",
		"updated_at":  "updated_at ASC",
		"-updated_at": "updated_at DESC",
		"unknown":     "",
		"":            "",
	}

	for in, want := range cases {
		if got := normalizeMedicineSort(in); got != want {
			t.Fatalf("normalizeMedicineSort(%q) = %q, want %q", in, got, want)
		}
	}
}
