package main

import (
	"bufio"
	"encoding/json"
	"os"
	"path/filepath"
	"testing"

	"github.com/orzogc/acfundanmu"
)

// 用真正的录制写入器（danmuWriter）产生 jsonl，再按合并的流程重排一遍，
// 验证「本程序自己录下来的弹幕」合出来和以前一模一样（弹道、宽度都不变）。
// 这也是手动合并与自动合并的分水岭：录制侧写文件完全不经过 relayoutLanes，
// 只有合并渲染前会重排，所以磁盘上的 .ass/.nick.ass/.jsonl 一个字节都不变。
func TestLiveRecordingPathUnaffected(t *testing.T) {
	dir := t.TempDir()
	cfg := acfundanmu.SubConfig{Title: "测试直播", PlayResX: 1920, PlayResY: 1080,
		FontSize: 48, StartTime: 1700000000000000000}
	ass := filepath.Join(dir, "live.ass")
	w := newDanmuWriter("liveid", "stream", cfg, ass)

	texts := []string{"来啦", "这首歌好听", "主播加油啊", "打卡打卡", "哈哈哈哈哈哈哈哈哈",
		"这条弹幕稍微长一点看看弹道到底怎么排"}
	for i := 0; i < 500; i++ {
		relMs := int64(i) * 220 // 平均 0.22 秒一条，够密集
		c := &acfundanmu.Comment{Content: texts[i%len(texts)]}
		c.SendTime = (cfg.StartTime + relMs*1e6) / 1e6
		c.UserID = int64(2000 + i%9)
		c.Nickname = "观众" + string(rune('A'+i%9))
		c.Avatar = "http://example.invalid/a.png"
		w.write(c)
	}
	w.close()

	f, err := os.Open(filepath.Join(dir, "live.jsonl"))
	if err != nil {
		t.Fatal(err)
	}
	defer f.Close()
	sc := bufio.NewScanner(f)
	sc.Buffer(make([]byte, 1<<20), 1<<20)
	var meta danmuMeta
	first := true
	var recs []danmuRecord
	for sc.Scan() {
		if first {
			json.Unmarshal(sc.Bytes(), &meta)
			first = false
			continue
		}
		var r danmuRecord
		if json.Unmarshal(sc.Bytes(), &r) == nil {
			recs = append(recs, r)
		}
	}
	type snap struct{ lane, width int }
	before := make([]snap, len(recs))
	for i, r := range recs {
		before[i] = snap{r.Lane, r.Width}
	}

	relayoutLanes(recs, meta)

	laneDiff, widthDiff := 0, 0
	for i, r := range recs {
		if r.Lane != before[i].lane {
			laneDiff++
			if laneDiff <= 3 {
				t.Logf("第 %d 条弹道变了：%d → %d", i, before[i].lane, r.Lane)
			}
		}
		if r.Width != before[i].width {
			widthDiff++
		}
	}
	t.Logf("录制产生 %d 条弹幕（含空内容 %d 条），重排后弹道变化 %d 条、宽度变化 %d 条",
		len(recs), countEmpty(recs), laneDiff, widthDiff)
	if laneDiff != 0 || widthDiff != 0 {
		t.Errorf("正常录制的弹幕重排后不应有任何变化")
	}
}

func countEmpty(recs []danmuRecord) int {
	n := 0
	for _, r := range recs {
		if r.Content == "" {
			n++
		}
	}
	return n
}