package core

import (
	"context"
	"testing"

	"github.com/kamelion/ratatoskr-go/internal/storage"
)

// mockDecider — тестовый Decider с заданным поведением.
type mockDecider struct {
	fn func(ctx context.Context, history []Message, draft storage.Task, force bool) (Decision, error)
}

func (m *mockDecider) Decide(ctx context.Context, history []Message, draft storage.Task, force bool) (Decision, error) {
	if m.fn != nil {
		return m.fn(ctx, history, draft, force)
	}
	return Decision{Phase: "ask", ChatReply: "ok"}, nil
}

func setupCore(t *testing.T, fn func(ctx context.Context, history []Message, draft storage.Task, force bool) (Decision, error)) (*Core, context.Context, *storage.Storage) {
	t.Helper()
	ctx := context.Background()
	store, err := storage.Open(ctx, ":memory:")
	if err != nil {
		t.Fatalf("storage.Open: %v", err)
	}
	t.Cleanup(func() { store.Close() })
	c := New(store, &mockDecider{fn: fn})
	return c, ctx, store
}

func mkTask(t *testing.T, store *storage.Storage, ctx context.Context, chatID string) int64 {
	t.Helper()
	id, err := store.CreateTask(ctx, &storage.Task{ChatID: chatID, TaskTag: "tag-" + chatID})
	if err != nil {
		t.Fatalf("CreateTask: %v", err)
	}
	return id
}

func TestStartCreatesCollecting(t *testing.T) {
	c, ctx, store := setupCore(t, nil)
	id := mkTask(t, store, ctx, "u1")

	res, err := c.ProcessTurn(ctx, id, "/start")
	if err != nil {
		t.Fatalf("ProcessTurn /start: %v", err)
	}
	if res.Action != "greeting" {
		t.Fatalf("action = %q, want greeting", res.Action)
	}
	task, _ := store.GetTask(ctx, id)
	if task.Status != storage.StatusCollecting {
		t.Fatalf("status = %s, want collecting", task.Status)
	}
}

func TestCancelSetsCancelled(t *testing.T) {
	c, ctx, store := setupCore(t, nil)
	id := mkTask(t, store, ctx, "u1")

	res, err := c.ProcessTurn(ctx, id, "/cancel")
	if err != nil {
		t.Fatalf("ProcessTurn /cancel: %v", err)
	}
	if res.Action != "drop" {
		t.Fatalf("action = %q, want drop", res.Action)
	}
	task, _ := store.GetTask(ctx, id)
	if task.Status != storage.StatusCancelled {
		t.Fatalf("status = %s, want cancelled", task.Status)
	}
}

func TestSingleTurnPropose(t *testing.T) {
	c, ctx, store := setupCore(t, func(ctx context.Context, history []Message, draft storage.Task, force bool) (Decision, error) {
		return Decision{
			Phase:     "propose",
			ChatReply: "Готово",
			Draft:     storage.Task{Title: "Новое", Goal: "Сделать", Repo: "acme/app"},
		}, nil
	})
	id := mkTask(t, store, ctx, "u1")

	res, err := c.ProcessTurn(ctx, id, "Сделай калькулятор")
	if err != nil {
		t.Fatalf("ProcessTurn: %v", err)
	}
	if res.Action != "summary" {
		t.Fatalf("action = %q, want summary", res.Action)
	}
	task, _ := store.GetTask(ctx, id)
	if task.Status != storage.StatusReady {
		t.Fatalf("status = %s, want ready", task.Status)
	}
	if task.Title != "Новое" {
		t.Fatalf("title = %q, want Новое", task.Title)
	}
}

func TestAskReturnsQuestions(t *testing.T) {
	c, ctx, store := setupCore(t, func(ctx context.Context, history []Message, draft storage.Task, force bool) (Decision, error) {
		return Decision{
			Phase:     "ask",
			ChatReply: "Уточню",
			Questions: []string{"Какой язык?", "Какой срок?"},
		}, nil
	})
	id := mkTask(t, store, ctx, "u1")

	res, err := c.ProcessTurn(ctx, id, "Напиши парсер")
	if err != nil {
		t.Fatalf("ProcessTurn: %v", err)
	}
	if res.Action != "send" {
		t.Fatalf("action = %q, want send", res.Action)
	}
	if res.Reply != "Уточню\n1. Какой язык?\n2. Какой срок?" {
		t.Fatalf("reply = %q", res.Reply)
	}
	// в фазе collecting — продолжaeм сбор
	task, _ := store.GetTask(ctx, id)
	if task.Status != storage.StatusCollecting {
		t.Fatalf("status = %s, want collecting", task.Status)
	}
}

func TestAbortReturnsDrop(t *testing.T) {
	c, ctx, store := setupCore(t, func(ctx context.Context, history []Message, draft storage.Task, force bool) (Decision, error) {
		return Decision{Phase: "abort", ChatReply: "Не хватает данных"}, nil
	})
	id := mkTask(t, store, ctx, "u1")

	res, err := c.ProcessTurn(ctx, id, "привет")
	if err != nil {
		t.Fatalf("ProcessTurn: %v", err)
	}
	if res.Action != "drop" {
		t.Fatalf("action = %q, want drop", res.Action)
	}
	task, _ := store.GetTask(ctx, id)
	if task.Status != storage.StatusAborted {
		t.Fatalf("status = %s, want aborted", task.Status)
	}
}

func TestConsentInReady(t *testing.T) {
	c, ctx, store := setupCore(t, func(ctx context.Context, history []Message, draft storage.Task, force bool) (Decision, error) {
		return Decision{Phase: "propose", Draft: storage.Task{Title: "X"}}, nil
	})
	id := mkTask(t, store, ctx, "u1")

	_, _ = c.ProcessTurn(ctx, id, "сделай задачу")
	res, err := c.ProcessTurn(ctx, id, "создавай")
	if err != nil {
		t.Fatalf("ProcessTurn создавай: %v", err)
	}
	if res.Action != "created:"+itoa(id) {
		t.Fatalf("action = %q, want created:%d", res.Action, id)
	}
}

func TestEditInReadyGoesCollecting(t *testing.T) {
	var calls int
	c, ctx, store := setupCore(t, func(ctx context.Context, history []Message, draft storage.Task, force bool) (Decision, error) {
		calls++
		return Decision{Phase: "propose", Draft: storage.Task{Title: "X"}}, nil
	})
	id := mkTask(t, store, ctx, "u1")

	_, _ = c.ProcessTurn(ctx, id, "сделай X")
	// в ready пишем правку, не согласие
	res, err := c.ProcessTurn(ctx, id, "нет, лучше Y")
	if err != nil {
		t.Fatalf("ProcessTurn edit: %v", err)
	}
	if res.Action != "summary" {
		t.Fatalf("action = %q, want summary", res.Action)
	}
	if calls != 2 {
		t.Fatalf("decide calls = %d, want 2", calls)
	}
	task, _ := store.GetTask(ctx, id)
	if task.Status != storage.StatusReady {
		t.Fatalf("status = %s, want ready", task.Status)
	}
}

func TestRetryNotFound(t *testing.T) {
	c, ctx, _ := setupCore(t, nil)
	res, err := c.ProcessTurn(ctx, 999, "/retry 999")
	if err != nil {
		t.Fatalf("ProcessTurn /retry: %v", err)
	}
	if res.Action != "send" {
		t.Fatalf("action = %q, want send", res.Action)
	}
}

func TestUnknownCommand(t *testing.T) {
	c, ctx, store := setupCore(t, nil)
	id := mkTask(t, store, ctx, "u1")

	res, err := c.ProcessTurn(ctx, id, "/bogus")
	if err != nil {
		t.Fatalf("ProcessTurn: %v", err)
	}
	if res.Action != "send" {
		t.Fatalf("action = %q, want send", res.Action)
	}
}

func TestParseTaskID(t *testing.T) {
	if v, ok := parseTaskID("5"); !ok || v != 5 {
		t.Fatalf("parseTaskID(5) = %d,%v", v, ok)
	}
	if v, ok := parseTaskID("123"); !ok || v != 123 {
		t.Fatalf("parseTaskID(123) = %d,%v", v, ok)
	}
	if _, ok := parseTaskID(""); ok {
		t.Fatal("parseTaskID('') should be invalid")
	}
	if _, ok := parseTaskID("abc"); ok {
		t.Fatal("parseTaskID(abc) should be invalid")
	}
}