package usage

import (
	"context"
	"fmt"
	"testing"
	"time"

	"github.com/openteam/server/internal/store"
	"github.com/shopspring/decimal"
)

// 保留期只删过期明细，余额流水一条不动；未开启（0）时什么都不做。
func TestRetentionPurgesOldLogsOnly(t *testing.T) {
	db := openTestDB(t)
	u := seedUser(t, db, 100)

	old := time.Now().UTC().AddDate(0, 0, -40)
	fresh := time.Now().UTC()
	for i := 0; i < 5; i++ {
		db.Create(&store.UsageLog{TraceID: fmt.Sprintf("old-%d", i), UserID: u, ModelName: "m1",
			Cost: decimal.NewFromFloat(0.01), Status: store.UsageStatusSuccess, CreatedAt: old})
	}
	for i := 0; i < 3; i++ {
		db.Create(&store.UsageLog{TraceID: fmt.Sprintf("new-%d", i), UserID: u, ModelName: "m1",
			Cost: decimal.NewFromFloat(0.01), Status: store.UsageStatusSuccess, CreatedAt: fresh})
	}
	db.Create(&store.BalanceLog{UserID: u, Change: decimal.NewFromFloat(-0.05), BalanceAfter: decimal.NewFromFloat(99.95),
		Type: store.BalanceTypeUsage, RefID: "usage:old-0"})

	n := purgeOlderThan(context.Background(), db, 30)
	if n != 5 {
		t.Fatalf("应删除 5 条过期明细，实际 %d", n)
	}
	var logs, ledgers int64
	db.Model(&store.UsageLog{}).Count(&logs)
	db.Model(&store.BalanceLog{}).Count(&ledgers)
	if logs != 3 {
		t.Fatalf("应保留 3 条新明细，实际 %d", logs)
	}
	if ledgers != 1 {
		t.Fatalf("余额流水不应被清理，实际 %d 条", ledgers)
	}
}

// 未配置保留期时不启动、不删数据。
func TestRetentionDisabled(t *testing.T) {
	db := openTestDB(t)
	u := seedUser(t, db, 100)
	db.Create(&store.UsageLog{TraceID: "x", UserID: u, ModelName: "m1",
		Cost: decimal.NewFromFloat(0.01), Status: store.UsageStatusSuccess,
		CreatedAt: time.Now().UTC().AddDate(0, 0, -400)})

	stop := StartRetention(context.Background(), db, 0)
	stop()
	var n int64
	db.Model(&store.UsageLog{}).Count(&n)
	if n != 1 {
		t.Fatalf("未开启保留期时不应删除数据，实际剩 %d", n)
	}
}

// 分批删除：行数超过一批时应全部删完。
func TestRetentionBatches(t *testing.T) {
	db := openTestDB(t)
	u := seedUser(t, db, 100)
	old := time.Now().UTC().AddDate(0, 0, -90)
	logs := make([]store.UsageLog, 0, retentionBatch+50)
	for i := 0; i < retentionBatch+50; i++ {
		logs = append(logs, store.UsageLog{TraceID: fmt.Sprintf("b-%d", i), UserID: u,
			ModelName: "m1", Cost: decimal.NewFromFloat(0.001), Status: store.UsageStatusSuccess, CreatedAt: old})
	}
	if err := db.CreateInBatches(logs, 500).Error; err != nil {
		t.Fatal(err)
	}
	n := purgeOlderThan(context.Background(), db, 30)
	if n != int64(len(logs)) {
		t.Fatalf("应删除 %d 条，实际 %d", len(logs), n)
	}
	var left int64
	db.Model(&store.UsageLog{}).Count(&left)
	if left != 0 {
		t.Fatalf("应全部删完，实际剩 %d", left)
	}
}