package faultRecordFile

import (
	"archive/zip"
	"bytes"
	"encoding/csv"
	"fmt"
	"io"
	"strconv"
)

var utf8Bom = []byte{0xEF, 0xBB, 0xBF} // 便于 Excel 识别中文

// ChannelLabel 通道表头：序号 + 含义代码（可配通道附类型和地址）
func ChannelLabel(ch WaveformChannel) string {
	if ch.Configurable != nil {
		return fmt.Sprintf("ch%d 可配%s", ch.Number, ConfigurableDesc(*ch.Configurable))
	}
	return fmt.Sprintf("ch%d 0x%04X", ch.Number, ch.Meaning)
}

// ConfigurableDesc 可配通道说明：默认方式为“类型@地址”，代码方式为“代码 0xXXXX”
func ConfigurableDesc(c ConfigurableChannel) string {
	if c.Mode == 1 {
		return fmt.Sprintf("代码0x%04X", c.Address>>16)
	}
	return fmt.Sprintf("%s@0x%X", c.TypeName, c.Address)
}

// WriteWaveformCSV 每行一个采样点：点序号、相对故障时刻毫秒、各通道原始值
func WriteWaveformCSV(w io.Writer, rec Record) error {
	if _, err := w.Write(utf8Bom); err != nil {
		return err
	}
	cw := csv.NewWriter(w)
	wf := rec.Waveform
	header := []string{"point", "time_ms"}
	for _, ch := range wf.Channels {
		header = append(header, ChannelLabel(ch))
	}
	if err := cw.Write(header); err != nil {
		return err
	}
	row := make([]string, len(header))
	for k := 0; k < wf.Points; k++ {
		row[0] = strconv.Itoa(k)
		row[1] = strconv.FormatFloat(wf.TimeOffsetMs(k), 'f', 3, 64)
		for c, ch := range wf.Channels {
			row[c+2] = strconv.Itoa(int(ch.Values[k]))
		}
		if err := cw.Write(row); err != nil {
			return err
		}
	}
	cw.Flush()
	return cw.Error()
}

// WriteSummaryCSV 基本信息、版本、触发源及各组通道
func WriteSummaryCSV(w io.Writer, rec Record) error {
	if _, err := w.Write(utf8Bom); err != nil {
		return err
	}
	cw := csv.NewWriter(w)
	f := rec.Failure
	rows := [][]string{
		{"项目", "值"},
		{"批次", rec.Batch},
		{"设备 SN", rec.Sn},
		{"记录序号", strconv.Itoa(rec.RecordIndex)},
		{"发生时间（设备时间）", f.Time},
		{"触发源", fmt.Sprintf("0x%04X %s", f.TriggerSource, f.TriggerSourceName)},
		{"CAN 协议版本", strconv.Itoa(int(f.Basic.CanProtocolVersion))},
		{"存储格式版本", strconv.Itoa(int(f.Basic.StorageFormat))},
		{"参数列表版本", f.Basic.ParamListVersion},
		{"最大采样频率 Hz", strconv.Itoa(int(f.Basic.MaxSampleFrequency))},
		{"采样频率 Hz", strconv.Itoa(int(f.Basic.SampleFrequency))},
		{"采样点总数", strconv.Itoa(int(f.Basic.TotalPoints))},
		{"故障前采样点", strconv.Itoa(int(f.Basic.PrePoints))},
		{"故障后采样点", strconv.Itoa(int(f.Basic.PostPoints))},
		{"DCDC 版本", f.DcdcVersion},
		{"INV 版本", f.InvVersion},
		{"FPGA 版本", f.FpgaVersion},
		{},
		{"快照通道", "含义代码", "原始值"},
	}
	for i, s := range f.Snapshots {
		v := ""
		if s.Value != nil {
			v = strconv.Itoa(int(*s.Value))
		}
		rows = append(rows, []string{strconv.Itoa(i), fmt.Sprintf("0x%04X", s.Meaning), v})
	}
	rows = append(rows, []string{}, []string{"采样通道", "含义代码"})
	for i, m := range f.SampleMeanings {
		rows = append(rows, []string{strconv.Itoa(i), fmt.Sprintf("0x%04X", m)})
	}
	rows = append(rows, []string{}, []string{"可配快照通道", "配置"})
	for i, c := range f.ConfigSnapshots {
		rows = append(rows, []string{strconv.Itoa(i), ConfigurableDesc(c)})
	}
	rows = append(rows, []string{}, []string{"可配采样通道", "配置"})
	for i, c := range f.ConfigSamples {
		rows = append(rows, []string{strconv.Itoa(i), ConfigurableDesc(c)})
	}
	if err := cw.WriteAll(rows); err != nil {
		return err
	}
	return cw.Error()
}

// BuildCSVZip 每条记录生成 waveform 和 summary 两个 CSV，打包为 zip
func BuildCSVZip(records []Record) ([]byte, error) {
	var buf bytes.Buffer
	zw := zip.NewWriter(&buf)
	for _, rec := range records {
		prefix := fmt.Sprintf("%s_%s_index%d", rec.Batch, rec.Sn, rec.RecordIndex)
		for _, item := range []struct {
			name  string
			write func(io.Writer, Record) error
		}{
			{prefix + "_waveform.csv", WriteWaveformCSV},
			{prefix + "_summary.csv", WriteSummaryCSV},
		} {
			fw, err := zw.Create(item.name)
			if err != nil {
				return nil, err
			}
			if err := item.write(fw, rec); err != nil {
				return nil, err
			}
		}
	}
	if err := zw.Close(); err != nil {
		return nil, err
	}
	return buf.Bytes(), nil
}