package plugin_snap

import (
	"bytes"
	"encoding/json"
	"fmt"
	"image"
	"image/color"
	_ "image/jpeg"
	"net/http"
	"os"
	"path/filepath"
	"runtime"
	"strconv"
	"strings"
	"time"

	"github.com/disintegration/imaging"
	m7s "m7s.live/v5"
	"m7s.live/v5/pkg"
	snap_pkg "m7s.live/v5/plugin/snap/pkg"
	"m7s.live/v5/plugin/snap/pkg/watermark"
)

const (
	MacFont   = "/System/Library/Fonts/STHeiti Light.ttc"                // mac字体路径
	LinuxFont = "/usr/share/fonts/opentype/noto/NotoSansCJK-Regular.ttc" // linux字体路径 思源黑体
	WinFont   = "C:/Windows/Fonts/msyh.ttf"                              // windows字体路径 微软雅黑
)

func parseRGBA(rgba string) (color.RGBA, error) {
	rgba = strings.TrimPrefix(rgba, "rgba(")
	rgba = strings.TrimSuffix(rgba, ")")
	parts := strings.Split(rgba, ",")
	if len(parts) != 4 {
		return color.RGBA{}, fmt.Errorf("invalid rgba format")
	}
	r, _ := strconv.Atoi(strings.TrimSpace(parts[0]))
	g, _ := strconv.Atoi(strings.TrimSpace(parts[1]))
	b, _ := strconv.Atoi(strings.TrimSpace(parts[2]))
	a, _ := strconv.ParseFloat(strings.TrimSpace(parts[3]), 64)
	return color.RGBA{uint8(r), uint8(g), uint8(b), uint8(a * 255)}, nil
}

// snap 方法负责实际的截图操作
func (p *SnapPlugin) snap(publisher *m7s.Publisher, watermarkConfig *snap_pkg.WatermarkConfig) (*bytes.Buffer, error) {

	// 获取视频帧
	annexb, _, err := snap_pkg.GetVideoFrame(publisher, p.Server)
	if err != nil {
		return nil, err
	}

	// 处理视频帧生成图片
	buf := new(bytes.Buffer)
	if err := snap_pkg.ProcessWithFFmpeg(annexb, buf); err != nil {
		return nil, err
	}

	// 如果设置了水印文字，添加水印
	if watermarkConfig != nil && watermarkConfig.Text != "" {
		// 加载字体
		if err := watermarkConfig.LoadFont(); err != nil {
			return nil, fmt.Errorf("load watermark font failed: %w", err)
		}

		// 解码图片
		img, _, err := image.Decode(bytes.NewReader(buf.Bytes()))
		if err != nil {
			return nil, fmt.Errorf("decode image failed: %w", err)
		}

		// 添加水印
		result, err := watermark.DrawWatermarkSingle(img, watermark.TextConfig{
			Text:       watermarkConfig.Text,
			Font:       watermarkConfig.Font,
			FontSize:   watermarkConfig.FontSize,
			Spacing:    watermarkConfig.FontSpacing,
			RowSpacing: 10,
			ColSpacing: 20,
			Rows:       1,
			Cols:       1,
			DPI:        72,
			Color:      watermarkConfig.FontColor,
			IsGrid:     false,
			Angle:      0,
			OffsetX:    watermarkConfig.OffsetX,
			OffsetY:    watermarkConfig.OffsetY,
		}, false)
		if err != nil {
			return nil, fmt.Errorf("add watermark failed: %w", err)
		}

		// 清空原buffer并写入新图片
		buf.Reset()
		if err := imaging.Encode(buf, result, imaging.JPEG); err != nil {
			return nil, fmt.Errorf("encode image failed: %w", err)
		}
	}

	return buf, nil
}

func (p *SnapPlugin) doSnap(rw http.ResponseWriter, r *http.Request) {
	streamPath := r.PathValue("streamPath")
	isUrl := r.URL.Query().Get("isUrl")

	// 获取发布者
	publisher, err := p.Server.GetPublisher(streamPath)
	if err != nil {
		http.Error(rw, pkg.ErrNotFound.Error(), http.StatusNotFound)
		return
	}

	// 获取查询参数
	query := r.URL.Query()

	// 从查询参数中获取水印配置
	var watermarkConfig *snap_pkg.WatermarkConfig
	watermarkText := query.Get("watermark")
	if watermarkText != "" {
		fontPath := query.Get("fontPath")
		if fontPath == "" {
			switch {
			case strings.Contains(runtime.GOOS, "darwin"):
				fontPath = MacFont
			case strings.Contains(runtime.GOOS, "linux"):
				fontPath = LinuxFont
			case strings.Contains(runtime.GOOS, "windows"):
				fontPath = WinFont
			}
		}
		watermarkConfig = &snap_pkg.WatermarkConfig{
			Text:        watermarkText,
			FontPath:    fontPath,
			FontSize:    parseFloat64(query.Get("fontSize"), 36),
			FontSpacing: parseFloat64(query.Get("fontSpacing"), 2),
			OffsetX:     parseInt(query.Get("offsetX"), 0),
			OffsetY:     parseInt(query.Get("offsetY"), 0),
		}

		// 解析颜色
		if fontColor := query.Get("fontColor"); fontColor != "" {
			if color, err := parseRGBA(fontColor); err == nil {
				watermarkConfig.FontColor = color
			}
		}
	}

	// 调用 snap 进行截图
	buf, err := p.snap(publisher, watermarkConfig)
	if err != nil {
		p.Error("snap failed", "error", err.Error())
		http.Error(rw, err.Error(), http.StatusInternalServerError)
		return
	}

	// 处理保存逻辑
	savePath := query.Get("savePath")
	now := time.Now()
	if savePath != "" {
		os.Mkdir(savePath, 0755)
		filename := fmt.Sprintf("%s_%s.jpg", streamPath, now.Format("20060102150405.000"))
		filename = strings.ReplaceAll(filename, "/", "_")
		savePath = filepath.Join(savePath, filename)

		// 保存到本地
		if err := os.WriteFile(savePath, buf.Bytes(), 0644); err != nil {
			p.Error("save snapshot failed", "error", err.Error())
			savePath = ""
		}

		// 保存截图记录到数据库
		if p.DB != nil && savePath != "" {
			record := snap_pkg.SnapRecord{
				StreamName: streamPath,
				SnapMode:   2, // HTTP请求截图模式
				SnapTime:   now,
				SnapPath:   savePath,
			}
			if err := p.DB.Create(&record).Error; err != nil {
				p.Error("save snapshot record failed", "error", err.Error())
			}
		}
	}

	if isUrl == "1" && savePath != "" {

		url := fmt.Sprintf("http://%s/snap/query/%s?snapTime=%d", "localhost:8080", streamPath, now.Unix())
		data := map[string]string{
			"url":      url,
			"markdown": fmt.Sprintf("![%s](%s)", streamPath, url),
		}
		rw.Header().Set("Content-Type", "application/json")
		if err := json.NewEncoder(rw).Encode(data); err != nil {
			http.Error(rw, err.Error(), http.StatusInternalServerError)
		}
	} else {
		// 返回图片
		rw.Header().Set("Content-Type", "image/jpeg")
		rw.Header().Set("Content-Length", strconv.Itoa(buf.Len()))
		if _, err := buf.WriteTo(rw); err != nil {
			p.Error("write response failed", "error", err.Error())
		}
	}

}

// 辅助函数：解析浮点数
func parseFloat64(s string, defaultValue float64) float64 {
	if s == "" {
		return defaultValue
	}
	v, err := strconv.ParseFloat(s, 64)
	if err != nil {
		return defaultValue
	}
	return v
}

// 辅助函数：解析整数
func parseInt(s string, defaultValue int) int {
	if s == "" {
		return defaultValue
	}
	v, err := strconv.Atoi(s)
	if err != nil {
		return defaultValue
	}
	return v
}

func (p *SnapPlugin) querySnap(rw http.ResponseWriter, r *http.Request) {
	if p.DB == nil {
		http.Error(rw, "database not initialized", http.StatusInternalServerError)
		return
	}

	streamPath := r.PathValue("streamPath")
	if streamPath == "" {
		http.Error(rw, "streamPath is required", http.StatusBadRequest)
		return
	}

	snapTimeStr := r.URL.Query().Get("snapTime")
	if snapTimeStr == "" {
		http.Error(rw, "snapTime is required", http.StatusBadRequest)
		return
	}

	snapTimeUnix, err := strconv.ParseInt(snapTimeStr, 10, 64)
	if err != nil {
		http.Error(rw, "invalid snapTime format, should be unix timestamp", http.StatusBadRequest)
		return
	}

	targetTime := time.Unix(snapTimeUnix+1, 0)
	var record snap_pkg.SnapRecord

	// 查询小于等于目标时间的最近一条记录
	if err := p.DB.Where("stream_name = ? AND snap_time <= ?", streamPath, targetTime).
		Order("id DESC").
		First(&record).Error; err != nil {
		http.Error(rw, "snapshot not found", http.StatusNotFound)
		return
	}

	// 计算时间差（秒）
	timeDiff := targetTime.Sub(record.SnapTime).Seconds()
	if timeDiff > float64(time.Duration(p.QueryTimeDelta)*time.Second) {
		http.Error(rw, "no snapshot found within time delta", http.StatusNotFound)
		return
	}

	// 读取图片文件
	imgData, err := os.ReadFile(record.SnapPath)
	if err != nil {
		http.Error(rw, "failed to read snapshot file", http.StatusNotFound)
		return
	}

	rw.Header().Set("Content-Type", "image/jpeg")
	rw.Header().Set("Content-Length", strconv.Itoa(len(imgData)))
	rw.Write(imgData)
}

func (p *SnapPlugin) RegisterHandler() map[string]http.HandlerFunc {
	return map[string]http.HandlerFunc{
		"/{streamPath...}":       p.doSnap,
		"/query/{streamPath...}": p.querySnap,
	}
}