package store

import (
	"testing"
)

func TestCreateChain_SeedsPositionsCorrectly(t *testing.T) {
	s := newNativeTasksTestStore(t)

	chain, err := s.CreateChain("Ham Radio Track", []string{"Study Technician", "Pass Technician exam", "Study General"})
	if err != nil {
		t.Fatalf("CreateChain: %v", err)
	}
	if chain.Status != "active" {
		t.Errorf("chain.Status = %q, want active", chain.Status)
	}

	tasks, err := s.GetChainTasks(chain.ID)
	if err != nil {
		t.Fatalf("GetChainTasks: %v", err)
	}
	if len(tasks) != 3 {
		t.Fatalf("len(tasks) = %d, want 3", len(tasks))
	}
	if !tasks[0].ChainUnlocked || tasks[0].DueDate == nil {
		t.Errorf("position 0: ChainUnlocked=%v DueDate=%v, want unlocked with a due date", tasks[0].ChainUnlocked, tasks[0].DueDate)
	}
	for i := 1; i < 3; i++ {
		if tasks[i].ChainUnlocked || tasks[i].DueDate != nil {
			t.Errorf("position %d: ChainUnlocked=%v DueDate=%v, want locked with no due date", i, tasks[i].ChainUnlocked, tasks[i].DueDate)
		}
	}
	if tasks[0].Content != "Study Technician" || tasks[1].Content != "Pass Technician exam" || tasks[2].Content != "Study General" {
		t.Errorf("unexpected content order: %q, %q, %q", tasks[0].Content, tasks[1].Content, tasks[2].Content)
	}
}

func TestCompleteNativeTask_AdvancesChain(t *testing.T) {
	s := newNativeTasksTestStore(t)

	chain, err := s.CreateChain("Track", []string{"Step 1", "Step 2"})
	if err != nil {
		t.Fatal(err)
	}
	tasks, err := s.GetChainTasks(chain.ID)
	if err != nil {
		t.Fatal(err)
	}

	if err := s.CompleteNativeTask(tasks[0].ID); err != nil {
		t.Fatalf("CompleteNativeTask: %v", err)
	}

	after, err := s.GetChainTasks(chain.ID)
	if err != nil {
		t.Fatal(err)
	}
	if !after[1].ChainUnlocked || after[1].DueDate == nil {
		t.Errorf("position 1 after completing position 0: ChainUnlocked=%v DueDate=%v, want unlocked with a due date", after[1].ChainUnlocked, after[1].DueDate)
	}

	updatedChain, err := s.GetChain(chain.ID)
	if err != nil {
		t.Fatal(err)
	}
	if updatedChain.Status != "active" {
		t.Errorf("chain.Status = %q, want active (not yet done)", updatedChain.Status)
	}
}

func TestCompleteNativeTask_LastPosition_MarksChainCompleted(t *testing.T) {
	s := newNativeTasksTestStore(t)

	chain, err := s.CreateChain("Track", []string{"Only step"})
	if err != nil {
		t.Fatal(err)
	}
	tasks, err := s.GetChainTasks(chain.ID)
	if err != nil {
		t.Fatal(err)
	}

	if err := s.CompleteNativeTask(tasks[0].ID); err != nil {
		t.Fatalf("CompleteNativeTask: %v", err)
	}

	updatedChain, err := s.GetChain(chain.ID)
	if err != nil {
		t.Fatal(err)
	}
	if updatedChain.Status != "completed" {
		t.Errorf("chain.Status = %q, want completed", updatedChain.Status)
	}
}

func TestCompleteNativeTask_PausedChain_DoesNotAdvance(t *testing.T) {
	s := newNativeTasksTestStore(t)

	chain, err := s.CreateChain("Track", []string{"Step 1", "Step 2"})
	if err != nil {
		t.Fatal(err)
	}
	if err := s.SetChainStatus(chain.ID, "paused"); err != nil {
		t.Fatal(err)
	}
	tasks, err := s.GetChainTasks(chain.ID)
	if err != nil {
		t.Fatal(err)
	}

	if err := s.CompleteNativeTask(tasks[0].ID); err != nil {
		t.Fatalf("CompleteNativeTask: %v", err)
	}

	after, err := s.GetChainTasks(chain.ID)
	if err != nil {
		t.Fatal(err)
	}
	if after[1].ChainUnlocked {
		t.Error("position 1 should still be locked while chain is paused")
	}

	// Resuming re-enables advancement on the *next* completion.
	if err := s.SetChainStatus(chain.ID, "active"); err != nil {
		t.Fatal(err)
	}
	if err := s.CompleteNativeTask(tasks[1].ID); err != nil {
		t.Fatalf("CompleteNativeTask after resume: %v", err)
	}
	updatedChain, err := s.GetChain(chain.ID)
	if err != nil {
		t.Fatal(err)
	}
	if updatedChain.Status != "completed" {
		t.Errorf("chain.Status = %q, want completed after resuming and finishing the last step", updatedChain.Status)
	}
}

func TestGetUndatedNativeTasks_ExcludesLockedChainTasks(t *testing.T) {
	s := newNativeTasksTestStore(t)

	chain, err := s.CreateChain("Track", []string{"Step 1", "Step 2", "Step 3"})
	if err != nil {
		t.Fatal(err)
	}
	_ = chain

	undated, err := s.GetUndatedNativeTasks()
	if err != nil {
		t.Fatalf("GetUndatedNativeTasks: %v", err)
	}
	for _, task := range undated {
		if task.ChainID != "" && !task.ChainUnlocked {
			t.Errorf("locked chain task %q leaked into GetUndatedNativeTasks", task.ID)
		}
	}
}

func TestGetChain_UnknownID_ReturnsErrNotFound(t *testing.T) {
	s := newNativeTasksTestStore(t)

	if _, err := s.GetChain("does-not-exist"); err != ErrNativeTaskNotFound {
		t.Errorf("err = %v, want ErrNativeTaskNotFound", err)
	}
}