package store_test

import (
	"fmt"
	"os"
	"path/filepath"
	"sync"
	"testing"

	"github.com/jfraeys/fetch_ml/internal/store"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestOpen(t *testing.T) {
	t.Parallel()

	dbPath := filepath.Join(t.TempDir(), "test_fetchml.db")

	s, err := store.Open(dbPath)
	require.NoError(t, err, "Failed to open database")
	defer s.Close()

	require.NotNil(t, s.DB(), "Database connection should not be nil")
}

func TestOpenCreatesDirectory(t *testing.T) {
	t.Parallel()

	tmpDir := t.TempDir()
	nestedPath := filepath.Join(tmpDir, "deep", "nested", "test.db")

	s, err := store.Open(nestedPath)
	require.NoError(t, err)
	defer s.Close()

	// Verify directory was created
	_, err = os.Stat(filepath.Dir(nestedPath))
	require.NoError(t, err, "Parent directory should be created")
}

func TestGetUnsyncedRuns(t *testing.T) {
	t.Parallel()

	dbPath := filepath.Join(t.TempDir(), "test_unsynced.db")
	s, err := store.Open(dbPath)
	require.NoError(t, err)
	defer s.Close()

	// Insert test data
	_, err = s.DB().Exec(`
		INSERT INTO ml_experiments (experiment_id, name) VALUES ('exp1', 'Test');
	`)
	require.NoError(t, err)

	_, err = s.DB().Exec(`
		INSERT INTO ml_runs (run_id, experiment_id, name, status, synced) 
		VALUES ('run1', 'exp1', 'Test Run', 'FINISHED', 0);
	`)
	require.NoError(t, err)

	runs, err := s.GetUnsyncedRuns()
	require.NoError(t, err)
	require.Len(t, runs, 1, "Expected 1 unsynced run")
	assert.Equal(t, "run1", runs[0].RunID)
}

func TestGetRunsByExperiment(t *testing.T) {
	t.Parallel()

	dbPath := filepath.Join(t.TempDir(), "test_by_exp.db")
	s, err := store.Open(dbPath)
	require.NoError(t, err)
	defer s.Close()

	// Insert test data
	_, err = s.DB().Exec(`
		INSERT INTO ml_experiments (experiment_id, name) VALUES ('exp1', 'Test');
	`)
	require.NoError(t, err)

	_, err = s.DB().Exec(`
		INSERT INTO ml_runs (run_id, experiment_id, name, status) 
		VALUES ('run1', 'exp1', 'Run 1', 'FINISHED');
	`)
	require.NoError(t, err)

	runs, err := s.GetRunsByExperiment("exp1")
	require.NoError(t, err)
	require.Len(t, runs, 1, "Expected 1 run for experiment")
	assert.Equal(t, "run1", runs[0].RunID)

	// Nonexistent experiment
	runs, err = s.GetRunsByExperiment("nonexistent")
	require.NoError(t, err)
	assert.Empty(t, runs)
}

func TestMarkRunSynced(t *testing.T) {
	t.Parallel()

	dbPath := filepath.Join(t.TempDir(), "test_sync.db")
	s, err := store.Open(dbPath)
	require.NoError(t, err)
	defer s.Close()

	// Insert test data
	_, err = s.DB().Exec(`
		INSERT INTO ml_experiments (experiment_id, name) VALUES ('exp1', 'Test');
	`)
	require.NoError(t, err)

	_, err = s.DB().Exec(`
		INSERT INTO ml_runs (run_id, experiment_id, name, status, synced) 
		VALUES ('run1', 'exp1', 'Test Run', 'FINISHED', 0);
	`)
	require.NoError(t, err)

	// Mark as synced
	err = s.MarkRunSynced("run1")
	require.NoError(t, err)

	// Verify
	var synced int
	err = s.DB().QueryRow("SELECT synced FROM ml_runs WHERE run_id = 'run1'").Scan(&synced)
	require.NoError(t, err)
	assert.Equal(t, 1, synced)
}

func TestGetRunMetrics(t *testing.T) {
	t.Parallel()

	dbPath := filepath.Join(t.TempDir(), "test_metrics.db")
	s, err := store.Open(dbPath)
	require.NoError(t, err)
	defer s.Close()

	// Insert test data
	_, err = s.DB().Exec(`
		INSERT INTO ml_experiments (experiment_id, name) VALUES ('exp1', 'Test');
	`)
	require.NoError(t, err)

	_, err = s.DB().Exec(`
		INSERT INTO ml_runs (run_id, experiment_id, name, status) 
		VALUES ('run1', 'exp1', 'Test Run', 'FINISHED');
	`)
	require.NoError(t, err)

	_, err = s.DB().Exec(`
		INSERT INTO ml_metrics (run_id, key, value, step) 
		VALUES ('run1', 'accuracy', 0.95, 1);
	`)
	require.NoError(t, err)

	metrics, err := s.GetRunMetrics("run1")
	require.NoError(t, err)
	require.Len(t, metrics, 1)
	assert.Equal(t, "accuracy", metrics[0].Key)
	assert.InDelta(t, 0.95, metrics[0].Value, 0.001)
}

func TestGetRunParams(t *testing.T) {
	t.Parallel()

	dbPath := filepath.Join(t.TempDir(), "test_params.db")
	s, err := store.Open(dbPath)
	require.NoError(t, err)
	defer s.Close()

	// Insert test data
	_, err = s.DB().Exec(`
		INSERT INTO ml_experiments (experiment_id, name) VALUES ('exp1', 'Test');
	`)
	require.NoError(t, err)

	_, err = s.DB().Exec(`
		INSERT INTO ml_runs (run_id, experiment_id, name, status) 
		VALUES ('run1', 'exp1', 'Test Run', 'FINISHED');
	`)
	require.NoError(t, err)

	_, err = s.DB().Exec(`
		INSERT INTO ml_params (run_id, key, value) 
		VALUES ('run1', 'learning_rate', '0.01');
	`)
	require.NoError(t, err)

	params, err := s.GetRunParams("run1")
	require.NoError(t, err)
	require.Len(t, params, 1)
	assert.Equal(t, "learning_rate", params[0].Key)
	assert.Equal(t, "0.01", params[0].Value)
}

func TestDB(t *testing.T) {
	t.Parallel()

	dbPath := filepath.Join(t.TempDir(), "test_db.db")
	s, err := store.Open(dbPath)
	require.NoError(t, err)
	defer s.Close()

	db := s.DB()
	require.NotNil(t, db)

	err = db.Ping()
	require.NoError(t, err, "DB connection should be valid")
}

// TestClose tests the Close method
func TestClose(t *testing.T) {
	t.Parallel()

	dbPath := filepath.Join(t.TempDir(), "test_close.db")
	s, err := store.Open(dbPath)
	require.NoError(t, err)

	err = s.Close()
	require.NoError(t, err)

	// Double close should not panic
	err = s.Close()
	assert.NoError(t, err)
}

// TestConcurrentLogMetrics tests concurrent metric logging
func TestConcurrentLogMetrics(t *testing.T) {
	t.Parallel()

	dbPath := filepath.Join(t.TempDir(), "test_concurrent.db")
	s, err := store.Open(dbPath)
	require.NoError(t, err)
	defer s.Close()

	// Insert test data
	_, err = s.DB().Exec(`INSERT INTO ml_experiments (experiment_id, name) VALUES ('exp1', 'Test');`)
	require.NoError(t, err)

	_, err = s.DB().Exec(`INSERT INTO ml_runs (run_id, experiment_id, name, status) VALUES ('run1', 'exp1', 'Test Run', 'FINISHED');`)
	require.NoError(t, err)

	// Concurrent inserts via raw SQL (simulating LogMetric behavior)
	// Note: SQLite may have locking contention, but should not panic
	var wg sync.WaitGroup
	for i := 0; i < 10; i++ {
		wg.Add(1)
		go func(i int) {
			defer wg.Done()
			// Use unique keys to avoid contention
			key := fmt.Sprintf("metric_%d", i)
			_, err := s.DB().Exec(`INSERT INTO ml_metrics (run_id, key, value, step) VALUES (?, ?, ?, ?)`,
				"run1", key, float64(i)/10.0, i)
			// Allow for SQLite locking errors in concurrent test
			if err != nil {
				t.Logf("Concurrent insert %d had error (expected with SQLite): %v", i, err)
			}
		}(i)
	}
	wg.Wait()

	// Verify metrics were recorded (some may fail due to SQLite locking)
	metrics, err := s.GetRunMetrics("run1")
	require.NoError(t, err)
	// Due to SQLite locking, not all may succeed, but at least some should
	assert.GreaterOrEqual(t, len(metrics), 1, "At least some metrics should be recorded")
}

// TestGetRunMetricsEmpty tests empty metrics result
func TestGetRunMetricsEmpty(t *testing.T) {
	t.Parallel()

	dbPath := filepath.Join(t.TempDir(), "test_empty_metrics.db")
	s, err := store.Open(dbPath)
	require.NoError(t, err)
	defer s.Close()

	// No metrics inserted
	metrics, err := s.GetRunMetrics("nonexistent-run")
	require.NoError(t, err)
	assert.Empty(t, metrics)
}

// TestGetRunParamsEmpty tests empty params result
func TestGetRunParamsEmpty(t *testing.T) {
	t.Parallel()

	dbPath := filepath.Join(t.TempDir(), "test_empty_params.db")
	s, err := store.Open(dbPath)
	require.NoError(t, err)
	defer s.Close()

	// No params inserted
	params, err := s.GetRunParams("nonexistent-run")
	require.NoError(t, err)
	assert.Empty(t, params)
}

// TestMarkRunSyncedNonexistent tests marking nonexistent run
func TestMarkRunSyncedNonexistent(t *testing.T) {
	t.Parallel()

	dbPath := filepath.Join(t.TempDir(), "test_sync_nonexistent.db")
	s, err := store.Open(dbPath)
	require.NoError(t, err)
	defer s.Close()

	// Should not error even if run doesn't exist
	err = s.MarkRunSynced("nonexistent-run")
	require.NoError(t, err)
}