package service

import (
	"archive/zip"
	"bytes"
	"errors"
	"io"
	"strings"
	"testing"

	"github.com/xuri/excelize/v2"
)

func TestParseMaterialImportFileStopsBeforeRowsBeyondLimit(t *testing.T) {
	dataRows := make([][]string, MaterialImportMaxRows+1)
	for i := range dataRows {
		dataRows[i] = []string{"物料", "", "", "机械结构类", "标准件"}
	}
	data := buildTestWorkbook(t, dataRows)
	reader, err := zip.NewReader(bytes.NewReader(data), int64(len(data)))
	if err != nil {
		t.Fatal(err)
	}
	var changed bytes.Buffer
	writer := zip.NewWriter(&changed)
	for _, entry := range reader.File {
		source, err := entry.Open()
		if err != nil {
			t.Fatal(err)
		}
		content, err := io.ReadAll(source)
		source.Close()
		if err != nil {
			t.Fatal(err)
		}
		if entry.Name == "xl/worksheets/sheet1.xml" {
			// 超限行之后故意放非法 XML，证明解析器不会再读取后续行。
			content = bytes.Replace(content, []byte("</sheetData>"),
				[]byte(`<row r="20003"><c></row></sheetData>`), 1)
		}
		target, err := writer.Create(entry.Name)
		if err != nil {
			t.Fatal(err)
		}
		if _, err := target.Write(content); err != nil {
			t.Fatal(err)
		}
	}
	if err := writer.Close(); err != nil {
		t.Fatal(err)
	}
	rows, err := ParseMaterialImportFile(bytes.NewReader(changed.Bytes()))
	if !errors.Is(err, ErrImportTooManyRows) || rows != nil {
		t.Fatalf("rows=%d, err=%v, want immediate ErrImportTooManyRows", len(rows), err)
	}
}

func TestParseMaterialImportFileAcceptsRowLimit(t *testing.T) {
	dataRows := make([][]string, MaterialImportMaxRows)
	for i := range dataRows {
		dataRows[i] = []string{"物料", "", "", "机械结构类", "标准件"}
	}
	rows, err := ParseMaterialImportFile(bytes.NewReader(buildTestWorkbook(t, dataRows)))
	if err != nil || len(rows) != MaterialImportMaxRows {
		t.Fatalf("rows=%d, err=%v", len(rows), err)
	}
}

func TestParseMaterialImportFileReadsRowsWithExcelRowNumbers(t *testing.T) {
	data := buildTestWorkbook(t, [][]string{
		{"内六角螺栓", "M8x30", "个", "机械结构类", "标准件"},
		{"", "", "", "", ""}, // 整行空，应被跳过
		{"急停按钮", "XB2", "个", "电气元器件类", "成品件"},
	})

	rows, err := ParseMaterialImportFile(bytes.NewReader(data))
	if err != nil {
		t.Fatalf("parse: %v", err)
	}
	if len(rows) != 2 {
		t.Fatalf("rows = %d, want 2", len(rows))
	}
	if rows[0].Row != 2 || rows[0].Name != "内六角螺栓" || rows[0].MinorName != "标准件" {
		t.Fatalf("first row = %+v", rows[0])
	}
	// 第 3 行是空行被跳过，所以第二条数据是 Excel 第 4 行
	if rows[1].Row != 4 || rows[1].Name != "急停按钮" {
		t.Fatalf("second row = %+v", rows[1])
	}
}

func TestParseMaterialImportFileKeepsRowsWithAnyContent(t *testing.T) {
	// 名称填了、其余为空：不是空行，必须保留交给校验去报错
	data := buildTestWorkbook(t, [][]string{
		{"只有名称", "", "", "", ""},
	})
	rows, err := ParseMaterialImportFile(bytes.NewReader(data))
	if err != nil {
		t.Fatalf("parse: %v", err)
	}
	if len(rows) != 1 || rows[0].Name != "只有名称" {
		t.Fatalf("rows = %+v", rows)
	}
}

func TestParseMaterialImportFileRejectsMissingRequiredColumn(t *testing.T) {
	// 只有「物料名称」和「规格」，缺必填的大类、小类
	data := buildTestWorkbookWithHeaders(t, []string{"物料名称", "规格"}, [][]string{
		{"内六角螺栓", "M8x30"},
	})

	_, err := ParseMaterialImportFile(bytes.NewReader(data))
	if !errors.Is(err, ErrImportTemplateInvalid) {
		t.Fatalf("err = %v, want ErrImportTemplateInvalid", err)
	}
}

func TestParseMaterialImportFileAcceptsMissingOptionalColumnsAndReorderedColumns(t *testing.T) {
	// 删掉「规格」，并把「单位」挪到「物料名称」前面
	headers := []string{"单位", "物料名称", "大类", "小类"}
	data := buildTestWorkbookWithHeaders(t, headers, [][]string{
		{"个", "内六角螺栓", "机械结构类", "标准件"},
	})

	rows, err := ParseMaterialImportFile(bytes.NewReader(data))
	if err != nil {
		t.Fatalf("parse: %v", err)
	}
	if len(rows) != 1 {
		t.Fatalf("rows = %d, want 1", len(rows))
	}
	if rows[0].Name != "内六角螺栓" || rows[0].Unit != "个" || rows[0].MinorName != "标准件" {
		t.Fatalf("row = %+v", rows[0])
	}
	if rows[0].Spec != "" {
		t.Fatalf("缺失的规格列应解析为空，得到 %q", rows[0].Spec)
	}
}

func TestParseMaterialImportFileIgnoresUnknownColumns(t *testing.T) {
	headers := []string{"物料名称", "备注", "大类", "小类"}
	data := buildTestWorkbookWithHeaders(t, headers, [][]string{
		{"内六角螺栓", "与导入无关", "机械结构类", "标准件"},
	})

	rows, err := ParseMaterialImportFile(bytes.NewReader(data))
	if err != nil {
		t.Fatalf("parse: %v", err)
	}
	if len(rows) != 1 || rows[0].Name != "内六角螺栓" {
		t.Fatalf("rows = %+v", rows)
	}
}

func TestParseMaterialImportFileRejectsTooManyRows(t *testing.T) {
	rows := make([][]string, 0, MaterialImportMaxRows+1)
	for i := 0; i < MaterialImportMaxRows+1; i++ {
		rows = append(rows, []string{"物料", "", "", "机械结构类", "标准件"})
	}
	data := buildTestWorkbook(t, rows)

	_, err := ParseMaterialImportFile(bytes.NewReader(data))
	if !errors.Is(err, ErrImportTooManyRows) {
		t.Fatalf("err = %v, want ErrImportTooManyRows", err)
	}
}

func TestBuildMaterialImportTemplateRoundTrips(t *testing.T) {
	data, err := BuildMaterialImportTemplate()
	if err != nil {
		t.Fatalf("build template: %v", err)
	}
	f, err := excelize.OpenReader(bytes.NewReader(data))
	if err != nil {
		t.Fatalf("open template: %v", err)
	}
	defer f.Close()
	sheets := f.GetSheetList()
	if len(sheets) != 2 || sheets[0] != MaterialImportSheetGuide || sheets[1] != MaterialImportSheetData {
		t.Fatalf("工作表顺序 = %v，期望先说明后填表", sheets)
	}
	if f.GetActiveSheetIndex() != 0 {
		t.Fatal("打开模板时应先显示填写说明")
	}
	guide, err := f.GetRows(MaterialImportSheetGuide)
	if err != nil {
		t.Fatal(err)
	}
	var guideText strings.Builder
	for _, row := range guide {
		guideText.WriteString(strings.Join(row, " "))
	}
	for _, rule := range []string{"编码 名称", "1MB", "10000", "整批", "重复", "库存", "第 2 行"} {
		if !strings.Contains(guideText.String(), rule) {
			t.Fatalf("填写说明缺少规则：%s", rule)
		}
	}
	styleAt := func(sheet, cell string) *excelize.Style {
		t.Helper()
		styleID, err := f.GetCellStyle(sheet, cell)
		if err != nil {
			t.Fatalf("读取 %s!%s 样式: %v", sheet, cell, err)
		}
		style, err := f.GetStyle(styleID)
		if err != nil {
			t.Fatalf("解析 %s!%s 样式: %v", sheet, cell, err)
		}
		return style
	}
	intro := styleAt(MaterialImportSheetGuide, "A2")
	if intro.Font == nil || !intro.Font.Bold || !intro.Font.Italic || intro.Fill.Color[0] != "FFC000" || intro.Alignment == nil || intro.Alignment.Horizontal != "" || intro.Alignment.Vertical != "center" {
		t.Fatalf("说明提示样式不匹配附件模板: %+v", intro)
	}
	field := styleAt(MaterialImportSheetGuide, "A6")
	if field.Font == nil || !field.Font.Bold {
		t.Fatalf("字段名应加粗: %+v", field)
	}
	required := styleAt(MaterialImportSheetGuide, "B6")
	if required.Font == nil || !required.Font.Bold || required.Font.Color != "FF0000" {
		t.Fatalf("必填标记应为红色粗体: %+v", required)
	}
	lastColumnWidth, err := f.GetColWidth(MaterialImportSheetData, "E")
	if err != nil || lastColumnWidth != 13 {
		t.Fatalf("物料数据 E 列宽 = %v, err = %v, want 13", lastColumnWidth, err)
	}

	if idx, _ := f.GetSheetIndex(MaterialImportSheetData); idx < 0 {
		t.Fatal("模板缺少「物料数据」工作表")
	}
	if idx, _ := f.GetSheetIndex(MaterialImportSheetGuide); idx < 0 {
		t.Fatal("模板缺少「填写说明」工作表")
	}
	headers, err := f.GetRows(MaterialImportSheetData)
	if err != nil {
		t.Fatalf("read rows: %v", err)
	}
	if len(headers) == 0 || headers[0][0] != "物料名称" || headers[0][4] != "小类" {
		t.Fatalf("表头 = %v", headers)
	}
	// 模板必须能被自己的解析器接受（表头一致）
	if rows, err := ParseMaterialImportFile(bytes.NewReader(data)); err != nil {
		t.Fatalf("模板无法被解析器接受: %v", err)
	} else if len(rows) != 0 {
		t.Fatal("数据页不应包含会被实际导入的示例物料")
	}
}

// buildTestWorkbook 用标准表头 + 给定数据行构造一个 xlsx 字节流。
func buildTestWorkbook(t *testing.T, dataRows [][]string) []byte {
	t.Helper()
	return buildTestWorkbookWithHeaders(t, materialImportHeaders, dataRows)
}

// buildTestWorkbookWithHeaders 允许指定表头，用来覆盖缺列、乱序、多余列的解析分支。
func buildTestWorkbookWithHeaders(t *testing.T, headers []string, dataRows [][]string) []byte {
	t.Helper()
	f := excelize.NewFile()
	defer f.Close()
	f.SetSheetName("Sheet1", MaterialImportSheetData)
	for i, header := range headers {
		cell, _ := excelize.CoordinatesToCellName(i+1, 1)
		f.SetCellValue(MaterialImportSheetData, cell, header)
	}
	for r, row := range dataRows {
		for c, value := range row {
			cell, _ := excelize.CoordinatesToCellName(c+1, r+2)
			f.SetCellValue(MaterialImportSheetData, cell, value)
		}
	}
	buf, err := f.WriteToBuffer()
	if err != nil {
		t.Fatalf("write workbook: %v", err)
	}
	return buf.Bytes()
}