package iot

import (
	"bytes"
	"context"
	"io"
	"time"

	v1 "git.5iot.com/iotlcm-public/iotlcm-admin-svr/api/iot/v1"
	"git.5iot.com/iotlcm-public/iotlcm-admin-svr/internal/library/contexts"
	"git.5iot.com/iotlcm-public/iotlcm-admin-svr/internal/library/exportcenter"
	"git.5iot.com/iotlcm-public/iotlcm-admin-svr/internal/logic/iot/simcardquery"
	"git.5iot.com/iotlcm-public/iotlcm-admin-svr/internal/model"
	"git.5iot.com/iotlcm-public/iotlcm-admin-svr/utility/iot_excelize"

	"github.com/gogf/gf/v2/errors/gerror"
	"github.com/gogf/gf/v2/frame/g"
	"github.com/gogf/gf/v2/net/ghttp"
)

// simCardQueryService 两个查询功能共用同一份实现，避免重复注册。
var simCardQueryService = simcardquery.New()

// SimCardBaseQueryTemplate 下载卡基础信息查询模板
func (c *ControllerV1) SimCardBaseQueryTemplate(ctx context.Context, req *v1.SimCardBaseQueryTemplateReq) (res *v1.SimCardBaseQueryTemplateRes, err error) {
	file, name, err := simCardQueryService.BaseTemplate(ctx)
	if err != nil {
		return nil, err
	}
	defer file.Close()
	return &v1.SimCardBaseQueryTemplateRes{}, iot_excelize.WriteHTTP(ctx, file, name)
}

// SimCardBaseQueryColumns 卡基础信息查询可选导出列
func (c *ControllerV1) SimCardBaseQueryColumns(ctx context.Context, req *v1.SimCardBaseQueryColumnsReq) (res *v1.SimCardBaseQueryColumnsRes, err error) {
	return &v1.SimCardBaseQueryColumnsRes{Items: simCardQueryService.BaseColumnOptions()}, nil
}

// SimCardBaseQueryExport 提交卡基础信息查询导出
func (c *ControllerV1) SimCardBaseQueryExport(ctx context.Context, req *v1.SimCardBaseQueryExportReq) (res *v1.SimCardBaseQueryExportRes, err error) {
	input, err := excelInput(ctx, req.Mode)
	if err != nil {
		return nil, err
	}
	submit, err := simCardQueryService.ExportBase(ctx, &req.SimCardQueryExportParam, input)
	if err != nil {
		return nil, err
	}
	return &v1.SimCardBaseQueryExportRes{SimCardQuerySubmitRes: toSubmitRes(submit)}, nil
}

// SimCardUsageHistoryTemplate 下载月历史用量查询模板
func (c *ControllerV1) SimCardUsageHistoryTemplate(ctx context.Context, req *v1.SimCardUsageHistoryTemplateReq) (res *v1.SimCardUsageHistoryTemplateRes, err error) {
	file, name, err := simCardQueryService.UsageHistoryTemplate(ctx)
	if err != nil {
		return nil, err
	}
	defer file.Close()
	return &v1.SimCardUsageHistoryTemplateRes{}, iot_excelize.WriteHTTP(ctx, file, name)
}

// SimCardUsageHistoryColumns 月历史用量查询固定列与近12个月月份清单
func (c *ControllerV1) SimCardUsageHistoryColumns(ctx context.Context, req *v1.SimCardUsageHistoryColumnsReq) (res *v1.SimCardUsageHistoryColumnsRes, err error) {
	return &v1.SimCardUsageHistoryColumnsRes{
		Items:  simCardQueryService.UsageHistoryColumnOptions(),
		Months: simCardQueryService.UsageHistoryMonths(time.Now()),
	}, nil
}

// SimCardUsageHistoryDeptOptions 月历史用量查询可选公司
func (c *ControllerV1) SimCardUsageHistoryDeptOptions(ctx context.Context, req *v1.SimCardUsageHistoryDeptOptionsReq) (res *v1.SimCardUsageHistoryDeptOptionsRes, err error) {
	items, err := simCardQueryService.DeptOptions(ctx)
	if err != nil {
		return nil, err
	}
	return &v1.SimCardUsageHistoryDeptOptionsRes{
		Items:         items,
		CurrentDeptId: contexts.GetDeptId(ctx),
	}, nil
}

// SimCardUsageHistoryExport 提交月历史用量查询导出
func (c *ControllerV1) SimCardUsageHistoryExport(ctx context.Context, req *v1.SimCardUsageHistoryExportReq) (res *v1.SimCardUsageHistoryExportRes, err error) {
	input, err := excelInput(ctx, req.Mode)
	if err != nil {
		return nil, err
	}
	submit, err := simCardQueryService.ExportUsageHistory(ctx, &req.SimCardUsageHistoryExportParam, input)
	if err != nil {
		return nil, err
	}
	return &v1.SimCardUsageHistoryExportRes{SimCardQuerySubmitRes: toSubmitRes(submit)}, nil
}

// excelInput 只在 Excel 模式下读取上传文件。
// 一次性读进内存再交给后台解析：提交接口必须立即返回，
// 而 HTTP 请求结束后临时上传文件可能被清理，不能在后台协程里再读。
func excelInput(ctx context.Context, mode string) (simcardquery.ExcelInput, error) {
	if mode != model.SimCardQueryModeExcel {
		return nil, nil
	}
	request := g.RequestFromCtx(ctx)
	if request == nil {
		return nil, gerror.New("当前上下文不是HTTP请求")
	}
	file := request.GetUploadFile("file")
	if file == nil {
		return nil, gerror.New("请先上传 Excel 文件")
	}
	content, err := readUploadContent(file)
	if err != nil {
		return nil, err
	}
	if len(content) == 0 {
		return nil, gerror.New("上传的 Excel 文件为空")
	}
	return func() (io.Reader, error) {
		return bytes.NewReader(content), nil
	}, nil
}

func toSubmitRes(submit *exportcenter.SubmitResult) *model.SimCardQuerySubmitRes {
	if submit == nil {
		return nil
	}
	return &model.SimCardQuerySubmitRes{
		TaskId: submit.TaskId,
		TaskNo: submit.TaskNo,
		Total:  submit.Total,
	}
}

// maxUploadBytes Excel 上传大小上限（MB 换算后的字节数）。
// 20MB 足够容纳 20000 行三列号码，再大基本是用户传错文件。
const maxUploadBytes = 20 << 20

// readUploadContent 一次性读出上传文件内容。
func readUploadContent(file *ghttp.UploadFile) ([]byte, error) {
	reader, err := file.Open()
	if err != nil {
		return nil, gerror.Wrap(err, "读取上传文件失败")
	}
	defer reader.Close()
	if file.Size > maxUploadBytes {
		return nil, gerror.Newf("上传文件超过 %dMB 上限", maxUploadBytes>>20)
	}
	content, err := io.ReadAll(reader)
	if err != nil {
		return nil, gerror.Wrap(err, "读取上传文件失败")
	}
	return content, nil
}