package storage

import (
	"bytes"
	"context"
	"io"
	"net/url"
	"strconv"
	"strings"
	"testing"
	"time"

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

func newTestStore(t *testing.T) *LocalFSStore {
	t.Helper()
	s, err := NewLocalFSStore(t.TempDir(), "http://localhost:3001/storage", "test-secret")
	require.NoError(t, err)
	return s
}

func TestLocalFSStore_PutGetStat(t *testing.T) {
	ctx := context.Background()
	s := newTestStore(t)

	payload := []byte("hello-visiona")
	key := "models/user-1/m1.nef"

	require.NoError(t, s.Put(ctx, key, bytes.NewReader(payload), int64(len(payload)), nil))

	// Stat
	info, err := s.Stat(ctx, key)
	require.NoError(t, err)
	assert.Equal(t, int64(len(payload)), info.Size)
	assert.Equal(t, key, info.Key)

	// Get
	rc, obj, err := s.Get(ctx, key)
	require.NoError(t, err)
	defer rc.Close()
	got, err := io.ReadAll(rc)
	require.NoError(t, err)
	assert.Equal(t, payload, got)
	assert.Equal(t, int64(len(payload)), obj.Size)
}

func TestLocalFSStore_Exists(t *testing.T) {
	ctx := context.Background()
	s := newTestStore(t)

	ok, err := s.Exists(ctx, "nope.txt")
	require.NoError(t, err)
	assert.False(t, ok, "不存在應回 (false, nil)")

	require.NoError(t, s.Put(ctx, "a.txt", strings.NewReader("x"), 1, nil))

	ok, err = s.Exists(ctx, "a.txt")
	require.NoError(t, err)
	assert.True(t, ok)
}

func TestLocalFSStore_Get_NotFound(t *testing.T) {
	s := newTestStore(t)
	_, _, err := s.Get(context.Background(), "missing.txt")
	assert.ErrorIs(t, err, ErrNotFound)
}

func TestLocalFSStore_Stat_NotFound(t *testing.T) {
	s := newTestStore(t)
	_, err := s.Stat(context.Background(), "missing.txt")
	assert.ErrorIs(t, err, ErrNotFound)
}

func TestLocalFSStore_Delete(t *testing.T) {
	ctx := context.Background()
	s := newTestStore(t)

	require.NoError(t, s.Put(ctx, "tmp.txt", strings.NewReader("x"), 1, nil))
	require.NoError(t, s.Delete(ctx, "tmp.txt"))

	ok, _ := s.Exists(ctx, "tmp.txt")
	assert.False(t, ok)

	// 刪除不存在的 key 不應回錯
	assert.NoError(t, s.Delete(ctx, "never.txt"))
}

func TestLocalFSStore_List(t *testing.T) {
	ctx := context.Background()
	s := newTestStore(t)

	require.NoError(t, s.Put(ctx, "models/u1/a.nef", strings.NewReader("A"), 1, nil))
	require.NoError(t, s.Put(ctx, "models/u1/b.nef", strings.NewReader("B"), 1, nil))
	require.NoError(t, s.Put(ctx, "models/u2/c.nef", strings.NewReader("C"), 1, nil))

	listU1, err := s.List(ctx, "models/u1")
	require.NoError(t, err)
	assert.Len(t, listU1, 2)

	listAll, err := s.List(ctx, "")
	require.NoError(t, err)
	assert.Len(t, listAll, 3)

	listEmpty, err := s.List(ctx, "not-exist-prefix")
	require.NoError(t, err)
	assert.Empty(t, listEmpty)
}

func TestLocalFSStore_PathTraversal_Rejected(t *testing.T) {
	ctx := context.Background()
	s := newTestStore(t)

	// 嘗試逃出 root
	err := s.Put(ctx, "../../etc/passwd", strings.NewReader("pwned"), 5, nil)
	assert.ErrorIs(t, err, ErrInvalidKey)

	_, _, err = s.Get(ctx, "../secret.txt")
	assert.ErrorIs(t, err, ErrInvalidKey)

	_, err = s.Stat(ctx, "../secret.txt")
	assert.ErrorIs(t, err, ErrInvalidKey)

	// 空 key
	err = s.Put(ctx, "", strings.NewReader("x"), 1, nil)
	assert.ErrorIs(t, err, ErrInvalidKey)
}

func TestLocalFSStore_PresignedGetURL_AndVerify(t *testing.T) {
	ctx := context.Background()
	s := newTestStore(t)

	key := "models/u1/m.nef"
	require.NoError(t, s.Put(ctx, key, strings.NewReader("X"), 1, nil))

	u, err := s.PresignedGetURL(ctx, key, 5*time.Minute)
	require.NoError(t, err)
	assert.Contains(t, u, "http://localhost:3001/storage/")
	assert.Contains(t, u, "expires=")
	assert.Contains(t, u, "signature=")

	// 解析並驗證
	parsed, err := url.Parse(u)
	require.NoError(t, err)
	expires, err := strconv.ParseInt(parsed.Query().Get("expires"), 10, 64)
	require.NoError(t, err)
	sig := parsed.Query().Get("signature")

	assert.NoError(t, s.VerifySignature("GET", key, expires, sig))

	// 簽名錯誤
	assert.ErrorIs(t, s.VerifySignature("GET", key, expires, "tampered"), ErrInvalidSignature)

	// 已過期
	assert.ErrorIs(t,
		s.VerifySignature("GET", key, time.Now().Add(-1*time.Hour).Unix(), sig),
		ErrInvalidSignature)

	// method 不符
	assert.ErrorIs(t, s.VerifySignature("PUT", key, expires, sig), ErrInvalidSignature)
}

func TestLocalFSStore_PresignedPutURL(t *testing.T) {
	s := newTestStore(t)
	u, err := s.PresignedPutURL(context.Background(), "models/u1/new.nef", 10*time.Minute)
	require.NoError(t, err)
	assert.Contains(t, u, "mode=put")
}

func TestNewLocalFSStore_EmptyRoot(t *testing.T) {
	_, err := NewLocalFSStore("", "", "")
	assert.Error(t, err)
}