// Copyright 2026 tamakyi. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.

package db

import (
	"context"
	"testing"
	"time"

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

func TestBoxViews(t *testing.T) {
	db, cleanup := newTestDB(t)
	ctx := context.Background()
	store := NewBoxViewsStore(db)

	for _, tc := range []struct {
		name string
		test func(t *testing.T, ctx context.Context, store BoxViewsStore)
	}{
		{"BatchMergesSameKey", testBoxViewsBatchMergesSameKey},
		{"AccumulatesAcrossCalls", testBoxViewsAccumulatesAcrossCalls},
		{"DailyAndTotals", testBoxViewsDailyAndTotals},
		{"PurgeKeepsRecent", testBoxViewsPurgeKeepsRecent},
	} {
		t.Run(tc.name, func(t *testing.T) {
			t.Cleanup(func() {
				if err := cleanup("box_views"); err != nil {
					t.Fatal(err)
				}
			})
			tc.test(t, ctx, store)
		})
	}
}

// 同一批里同 (user, day, visitor) 出现多次时，必须先在内存合并再写。
//
// PostgreSQL 的 ON CONFLICT DO UPDATE 不允许同一条 INSERT 两次命中同一行
// （"ON CONFLICT DO UPDATE command cannot affect row a second time"），
// 不合并的话记录器一次 flush 就会整批失败 —— 而 flush 里恰好可能包含
// 同一访客在 2 秒内刷新三次的记录。
func testBoxViewsBatchMergesSameKey(t *testing.T, ctx context.Context, store BoxViewsStore) {
	now := time.Date(2026, 10, 29, 15, 4, 5, 0, time.Local)

	// 同一访客三次 + 另一个访客一次，全在同一批里
	err := store.RecordBatch(ctx, []RecordBoxViewOptions{
		{UserID: 7, ViewedOn: now, Visitor: "aaaa"},
		{UserID: 7, ViewedOn: now, Visitor: "aaaa"},
		{UserID: 7, ViewedOn: now, Visitor: "aaaa"},
		{UserID: 7, ViewedOn: now, Visitor: "bbbb"},
	})
	require.NoError(t, err)

	pv, uv, err := store.Totals(ctx, 7)
	require.NoError(t, err)
	require.Equal(t, int64(4), pv, "三次重复访问应累加进 views")
	require.Equal(t, int64(2), uv, "同一访客当天只算一个 UV")
}

func testBoxViewsAccumulatesAcrossCalls(t *testing.T, ctx context.Context, store BoxViewsStore) {
	day := time.Date(2026, 10, 28, 9, 0, 0, 0, time.Local)

	require.NoError(t, store.Record(ctx, RecordBoxViewOptions{UserID: 3, ViewedOn: day, Visitor: "x"}))
	require.NoError(t, store.Record(ctx, RecordBoxViewOptions{UserID: 3, ViewedOn: day, Visitor: "x"}))
	require.NoError(t, store.Record(ctx, RecordBoxViewOptions{UserID: 3, ViewedOn: day, Visitor: "y"}))

	pv, uv, err := store.Totals(ctx, 3)
	require.NoError(t, err)
	require.Equal(t, int64(3), pv)
	require.Equal(t, int64(2), uv)
}

func testBoxViewsDailyAndTotals(t *testing.T, ctx context.Context, store BoxViewsStore) {
	base := time.Date(2026, 10, 20, 12, 0, 0, 0, time.Local)

	// 20 日：2 访客共 3 次；21 日：1 访客 1 次；22 日：无记录
	require.NoError(t, store.RecordBatch(ctx, []RecordBoxViewOptions{
		{UserID: 11, ViewedOn: base, Visitor: "a"},
		{UserID: 11, ViewedOn: base, Visitor: "a"},
		{UserID: 11, ViewedOn: base, Visitor: "b"},
		{UserID: 11, ViewedOn: base.AddDate(0, 0, 1), Visitor: "a"},
	}))
	// 另一个箱主的数据不能串进来
	require.NoError(t, store.Record(ctx, RecordBoxViewOptions{
		UserID: 12, ViewedOn: base, Visitor: "a",
	}))

	days, err := store.Daily(ctx, 11, base, base.AddDate(0, 0, 2))
	require.NoError(t, err)
	require.Len(t, days, 2, "没有记录的那天不返回，由上层补零")

	require.Equal(t, "2026-10-20", days[0].Day.Format("2006-01-02"))
	require.Equal(t, int64(3), days[0].PV)
	require.Equal(t, int64(2), days[0].UV)

	require.Equal(t, "2026-10-21", days[1].Day.Format("2006-01-02"))
	require.Equal(t, int64(1), days[1].PV)
	require.Equal(t, int64(1), days[1].UV)

	pv, uv, err := store.Totals(ctx, 11)
	require.NoError(t, err)
	require.Equal(t, int64(4), pv)
	require.Equal(t, int64(3), uv)

	first, err := store.FirstDay(ctx, 11)
	require.NoError(t, err)
	require.Equal(t, "2026-10-20", first.Format("2006-01-02"))
}

func testBoxViewsPurgeKeepsRecent(t *testing.T, ctx context.Context, store BoxViewsStore) {
	old := time.Now().AddDate(0, 0, -30)
	recent := time.Now()

	require.NoError(t, store.RecordBatch(ctx, []RecordBoxViewOptions{
		{UserID: 5, ViewedOn: old, Visitor: "a"},
		{UserID: 5, ViewedOn: recent, Visitor: "b"},
	}))

	n, err := store.Purge(ctx, time.Now().AddDate(0, 0, -7))
	require.NoError(t, err)
	require.Equal(t, int64(1), n)

	pv, uv, err := store.Totals(ctx, 5)
	require.NoError(t, err)
	require.Equal(t, int64(1), pv, "只保留保留期内的行")
	require.Equal(t, int64(1), uv)
}