package redis

// Tests for Redis config and client behavior.

import (
	"context"
	"errors"
	"net"
	"strconv"
	"testing"
	"time"

	"github.com/alicebob/miniredis/v2"
	redisv9 "github.com/redis/go-redis/v9"
	"github.com/stretchr/testify/require"
)

// TestDefaultConfig ensures default config behavior is handled correctly.
func TestDefaultConfig(t *testing.T) {
	cfg := DefaultConfig()
	require.Equal(t, "localhost", cfg.Host)
	require.Equal(t, 6379, cfg.Port)
}

// TestAddr ensures addr behavior is handled correctly.
func TestAddr(t *testing.T) {
	cfg := DefaultConfig()
	require.Equal(t, "localhost:6379", cfg.Addr())
}

// newClientForMiniRedis creates in-memory test doubles and deterministic fixtures.
func newClientForMiniRedis(t *testing.T) (*Client, *miniredis.Miniredis) {
	t.Helper()

	mr := miniredis.RunT(t)
	cfg := DefaultConfig()
	host, portStr, err := net.SplitHostPort(mr.Addr())
	require.NoError(t, err)
	port, err := strconv.Atoi(portStr)
	require.NoError(t, err)
	cfg.Host = host
	cfg.Port = port

	client, err := NewClient(cfg)
	require.NoError(t, err)
	t.Cleanup(func() {
		_ = client.Close()
	})

	return client, mr
}

// TestHealthCheck ensures health check behavior is handled correctly.
func TestHealthCheck(t *testing.T) {
	client, _ := newClientForMiniRedis(t)
	require.NoError(t, client.HealthCheck(context.Background()))
}

// TestSetGet ensures set get behavior is handled correctly.
func TestSetGet(t *testing.T) {
	client, _ := newClientForMiniRedis(t)
	ctx := context.Background()

	require.NoError(t, client.Set(ctx, "k", "v", 0))

	got, err := client.Get(ctx, "k")
	require.NoError(t, err)
	require.Equal(t, "v", got)
}

// TestDeleteExists ensures delete exists behavior is handled correctly.
func TestDeleteExists(t *testing.T) {
	client, _ := newClientForMiniRedis(t)
	ctx := context.Background()

	require.NoError(t, client.Set(ctx, "k", "v", 0))
	exists, err := client.Exists(ctx, "k")
	require.NoError(t, err)
	require.True(t, exists)

	require.NoError(t, client.Delete(ctx, "k"))
	exists, err = client.Exists(ctx, "k")
	require.NoError(t, err)
	require.False(t, exists)
}

// TestIncr ensures incr behavior is handled correctly.
func TestIncr(t *testing.T) {
	client, _ := newClientForMiniRedis(t)
	ctx := context.Background()

	n, err := client.Incr(ctx, "counter")
	require.NoError(t, err)
	require.Equal(t, int64(1), n)

	n, err = client.Incr(ctx, "counter")
	require.NoError(t, err)
	require.Equal(t, int64(2), n)
}

// TestExpire ensures expire behavior is handled correctly.
func TestExpire(t *testing.T) {
	client, mr := newClientForMiniRedis(t)
	ctx := context.Background()

	require.NoError(t, client.Set(ctx, "temp", "value", 0))
	require.NoError(t, client.Expire(ctx, "temp", time.Second))

	mr.FastForward(2 * time.Second)

	_, err := client.Get(ctx, "temp")
	require.Error(t, err)
	require.True(t, errors.Is(err, redisv9.Nil))
}

// TestGetNotFound ensures get not found behavior is handled correctly.
func TestGetNotFound(t *testing.T) {
	client, _ := newClientForMiniRedis(t)
	_, err := client.Get(context.Background(), "missing")
	require.Error(t, err)
	require.True(t, errors.Is(err, redisv9.Nil))
}

// TestConfigFromEnvDefaults ensures config from env defaults behavior is handled correctly.
func TestConfigFromEnvDefaults(t *testing.T) {
	t.Setenv("REDIS_HOST", "")
	t.Setenv("REDIS_PORT", "")
	cfg := ConfigFromEnv()
	def := DefaultConfig()
	require.Equal(t, def.Host, cfg.Host)
	require.Equal(t, def.Port, cfg.Port)
}

// TestConfigFromEnvOverrides ensures config from env overrides behavior is handled correctly.
func TestConfigFromEnvOverrides(t *testing.T) {
	t.Setenv("REDIS_HOST", "cache")
	t.Setenv("REDIS_PORT", "6380")
	t.Setenv("REDIS_PASSWORD", "secret")
	t.Setenv("REDIS_DB", "2")
	t.Setenv("REDIS_POOL_SIZE", "25")
	t.Setenv("REDIS_MIN_IDLE_CONNS", "3")
	t.Setenv("REDIS_DIAL_TIMEOUT", "2s")
	t.Setenv("REDIS_READ_TIMEOUT", "4s")
	t.Setenv("REDIS_WRITE_TIMEOUT", "5s")

	cfg := ConfigFromEnv()
	require.Equal(t, "cache", cfg.Host)
	require.Equal(t, 6380, cfg.Port)
	require.Equal(t, "secret", cfg.Password)
	require.Equal(t, 2, cfg.DB)
	require.Equal(t, 25, cfg.PoolSize)
	require.Equal(t, 3, cfg.MinIdleConns)
	require.Equal(t, 2*time.Second, cfg.DialTimeout)
	require.Equal(t, 4*time.Second, cfg.ReadTimeout)
	require.Equal(t, 5*time.Second, cfg.WriteTimeout)
}

// TestNewClientInvalidConfig ensures new client invalid config behavior is handled correctly.
func TestNewClientInvalidConfig(t *testing.T) {
	cfg := DefaultConfig()
	cfg.Port = 0
	_, err := NewClient(cfg)
	require.Error(t, err)
}