package postgres

// Tests for PostgreSQL config helpers and health check behavior.

import (
	"context"
	"testing"
	"time"

	"github.com/stretchr/testify/require"
)

// TestDefaultConfig verifies default configuration values for the client.
func TestDefaultConfig(t *testing.T) {
	cfg := DefaultConfig()
	require.Equal(t, "localhost", cfg.Host)
	require.Equal(t, 5432, cfg.Port)
}

// TestConfigDSNAndURL verifies DSN and URL formatting include expected parts.
func TestConfigDSNAndURL(t *testing.T) {
	cfg := DefaultConfig()
	require.Contains(t, cfg.DSN(), "host=localhost")
	require.Contains(t, cfg.URL(), "postgresql://")
}

// TestConfigFromEnvDefaults verifies defaults are used when env vars are absent.
func TestConfigFromEnvDefaults(t *testing.T) {
	t.Setenv("POSTGRES_HOST", "")
	t.Setenv("POSTGRES_PORT", "")
	t.Setenv("POSTGRES_USER", "")
	t.Setenv("POSTGRES_PASSWORD", "")
	t.Setenv("POSTGRES_DB", "")
	t.Setenv("POSTGRES_SSLMODE", "")

	cfg := ConfigFromEnv()
	def := DefaultConfig()

	require.Equal(t, def.Host, cfg.Host)
	require.Equal(t, def.Port, cfg.Port)
	require.Equal(t, def.User, cfg.User)
	require.Equal(t, def.Password, cfg.Password)
	require.Equal(t, def.Database, cfg.Database)
	require.Equal(t, def.SSLMode, cfg.SSLMode)
}

// TestConfigFromEnvOverrides verifies valid env vars override defaults.
func TestConfigFromEnvOverrides(t *testing.T) {
	t.Setenv("POSTGRES_HOST", "db")
	t.Setenv("POSTGRES_PORT", "15432")
	t.Setenv("POSTGRES_USER", "user")
	t.Setenv("POSTGRES_PASSWORD", "secret")
	t.Setenv("POSTGRES_DB", "app")
	t.Setenv("POSTGRES_SSLMODE", "require")
	t.Setenv("POSTGRES_MAX_OPEN_CONNS", "50")
	t.Setenv("POSTGRES_MAX_IDLE_CONNS", "20")
	t.Setenv("POSTGRES_CONN_MAX_LIFETIME", "10m")
	t.Setenv("POSTGRES_CONN_MAX_IDLE_TIME", "2m")

	cfg := ConfigFromEnv()
	require.Equal(t, "db", cfg.Host)
	require.Equal(t, 15432, cfg.Port)
	require.Equal(t, "user", cfg.User)
	require.Equal(t, "secret", cfg.Password)
	require.Equal(t, "app", cfg.Database)
	require.Equal(t, "require", cfg.SSLMode)
	require.Equal(t, 50, cfg.MaxOpenConns)
	require.Equal(t, 20, cfg.MaxIdleConns)
	require.Equal(t, 10*time.Minute, cfg.ConnMaxLifetime)
	require.Equal(t, 2*time.Minute, cfg.ConnMaxIdleTime)
}

// TestConfigFromEnvInvalidFallsBack verifies invalid numeric/duration values fall back.
func TestConfigFromEnvInvalidFallsBack(t *testing.T) {
	def := DefaultConfig()
	t.Setenv("POSTGRES_PORT", "not-a-number")
	t.Setenv("POSTGRES_MAX_OPEN_CONNS", "x")
	t.Setenv("POSTGRES_CONN_MAX_LIFETIME", "invalid")

	cfg := ConfigFromEnv()
	require.Equal(t, def.Port, cfg.Port)
	require.Equal(t, def.MaxOpenConns, cfg.MaxOpenConns)
	require.Equal(t, def.ConnMaxLifetime, cfg.ConnMaxLifetime)
}

// TestHealthCheckInvalidConfig verifies config validation runs before DB connection.
func TestHealthCheckInvalidConfig(t *testing.T) {
	cfg := DefaultConfig()
	cfg.Host = ""

	err := HealthCheck(context.Background(), cfg)
	require.Error(t, err)
	require.Contains(t, err.Error(), "host is required")
}

// TestHealthCheckConnectionFailure verifies connection issues are surfaced.
func TestHealthCheckConnectionFailure(t *testing.T) {
	cfg := DefaultConfig()
	cfg.Host = "127.0.0.1"
	cfg.Port = 65432 // typically closed

	err := HealthCheck(context.Background(), cfg)
	require.Error(t, err)
}