package store

import (
	"database/sql"
	"errors"
	"path/filepath"
	"testing"
	"time"

	"task-dashboard/internal/models"

	_ "github.com/mattn/go-sqlite3"
)

// newNativeTasksTestStore creates a Store backed by a fresh temp sqlite DB
// with just the native_tasks table -- enough to exercise
// CompleteNativeTask/UncompleteNativeTask/RescheduleNativeTask without
// running the full migration set.
func newNativeTasksTestStore(t *testing.T) *Store {
	t.Helper()
	dbPath := filepath.Join(t.TempDir(), "test.db")
	db, err := sql.Open("sqlite3", dbPath)
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { db.Close() })
	if _, err := db.Exec(`
		CREATE TABLE native_tasks (
			id TEXT PRIMARY KEY,
			content TEXT NOT NULL,
			description TEXT DEFAULT '',
			project_name TEXT DEFAULT '',
			due_date DATETIME,
			priority INTEGER DEFAULT 1,
			completed BOOLEAN DEFAULT 0,
			labels TEXT DEFAULT '[]',
			created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
			updated_at DATETIME DEFAULT CURRENT_TIMESTAMP,
			recurrence_freq TEXT DEFAULT '',
			recurrence_interval INTEGER DEFAULT 1,
			recurrence_weekdays TEXT DEFAULT '',
			recurrence_series_id TEXT DEFAULT '',
			next_occurrence_override TEXT DEFAULT ''
		)
	`); err != nil {
		t.Fatal(err)
	}
	if _, err := db.Exec(`INSERT INTO native_tasks (id, content) VALUES ('real-1', 'Real task')`); err != nil {
		t.Fatal(err)
	}
	return &Store{db: db}
}

// TestCompleteNativeTask_UnknownID_ReturnsErrNotFound proves the 2026-07-12
// fix: a plain UPDATE ... WHERE id = ? silently "succeeds" with a nil error
// when 0 rows match (this is how database/sql's Exec behaves for an UPDATE
// that matches nothing -- no error, just RowsAffected() == 0). Before this
// fix, CompleteNativeTask returned that nil error straight through, so a
// stale/wrong id from a caller (the Android widget, in the real incident
// this was found from) looked identical to a real completion: HTTP 200,
// nothing changed in the database.
func TestCompleteNativeTask_UnknownID_ReturnsErrNotFound(t *testing.T) {
	s := newNativeTasksTestStore(t)

	err := s.CompleteNativeTask("does-not-exist")
	if !errors.Is(err, ErrNativeTaskNotFound) {
		t.Fatalf("expected ErrNativeTaskNotFound, got %v", err)
	}
}

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

	if err := s.CompleteNativeTask("real-1"); err != nil {
		t.Fatalf("CompleteNativeTask: %v", err)
	}

	var completed bool
	if err := s.db.QueryRow(`SELECT completed FROM native_tasks WHERE id = 'real-1'`).Scan(&completed); err != nil {
		t.Fatal(err)
	}
	if !completed {
		t.Error("expected task to be marked completed")
	}
}

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

	err := s.UncompleteNativeTask("does-not-exist")
	if !errors.Is(err, ErrNativeTaskNotFound) {
		t.Fatalf("expected ErrNativeTaskNotFound, got %v", err)
	}
}

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

	err := s.RescheduleNativeTask("does-not-exist", time.Now())
	if !errors.Is(err, ErrNativeTaskNotFound) {
		t.Fatalf("expected ErrNativeTaskNotFound, got %v", err)
	}
}

func TestGetNativeTasks_ParsesRecurrenceFields(t *testing.T) {
	s := newNativeTasksTestStore(t)
	if _, err := s.db.Exec(`
		INSERT INTO native_tasks (id, content, due_date, recurrence_freq, recurrence_interval, recurrence_weekdays, recurrence_series_id, next_occurrence_override)
		VALUES ('rec-1', 'Recurring task', '2026-07-13', 'weekly', 2, '1,3,5', 'series-abc', '2026-07-27')
	`); err != nil {
		t.Fatal(err)
	}

	tasks, err := s.GetNativeTasks()
	if err != nil {
		t.Fatalf("GetNativeTasks: %v", err)
	}

	var found *models.Task
	for i := range tasks {
		if tasks[i].ID == "rec-1" {
			found = &tasks[i]
		}
	}
	if found == nil {
		t.Fatal("expected to find rec-1")
	}
	if found.RecurrenceFreq != "weekly" {
		t.Errorf("RecurrenceFreq = %q, want %q", found.RecurrenceFreq, "weekly")
	}
	if found.RecurrenceInterval != 2 {
		t.Errorf("RecurrenceInterval = %d, want 2", found.RecurrenceInterval)
	}
	if len(found.RecurrenceWeekdays) != 3 || found.RecurrenceWeekdays[0] != 1 || found.RecurrenceWeekdays[1] != 3 || found.RecurrenceWeekdays[2] != 5 {
		t.Errorf("RecurrenceWeekdays = %v, want [1 3 5]", found.RecurrenceWeekdays)
	}
	if found.RecurrenceSeriesID != "series-abc" {
		t.Errorf("RecurrenceSeriesID = %q, want %q", found.RecurrenceSeriesID, "series-abc")
	}
	if found.NextOccurrenceOverride == nil || found.NextOccurrenceOverride.Format("2006-01-02") != "2026-07-27" {
		t.Errorf("NextOccurrenceOverride = %v, want 2026-07-27", found.NextOccurrenceOverride)
	}
}

func TestGetNativeTasks_NonRecurringTask_HasEmptyRecurrenceFields(t *testing.T) {
	s := newNativeTasksTestStore(t)
	// "real-1" (inserted by newNativeTasksTestStore) has no recurrence columns set.
	tasks, err := s.GetNativeTasks()
	if err != nil {
		t.Fatalf("GetNativeTasks: %v", err)
	}
	var found *models.Task
	for i := range tasks {
		if tasks[i].ID == "real-1" {
			found = &tasks[i]
		}
	}
	if found == nil {
		t.Fatal("expected to find real-1")
	}
	if found.RecurrenceSeriesID != "" {
		t.Errorf("expected empty RecurrenceSeriesID for non-recurring task, got %q", found.RecurrenceSeriesID)
	}
	if found.RecurrenceWeekdays != nil {
		t.Errorf("expected nil RecurrenceWeekdays for non-recurring task, got %v", found.RecurrenceWeekdays)
	}
	if found.NextOccurrenceOverride != nil {
		t.Errorf("expected nil NextOccurrenceOverride for non-recurring task, got %v", found.NextOccurrenceOverride)
	}
}