package api

import (
	"context"
	"fmt"
	"regexp"
	"sort"
	"strconv"
	"strings"
	"time"

	"dana/internal/sberhealth"
)

type sberhealthSourceInfo struct {
	From          string `json:"from"`
	To            string `json:"to"`
	Records       int    `json:"records"`        // creation date inside 1C period
	Phones        int    `json:"phones"`         // unique keys before 1C stub exclusions
	ExportRecords int    `json:"export_records"` // reconciled with XLS footer
}

func (a *API) WithSberHealth(c *sberhealth.Client) { a.sberhealth = c }

func (a *API) sberhealthMatchOpts(ctx context.Context, from, to time.Time) (matchOpts, error) {
	if !a.sberhealth.Configured() {
		return matchOpts{}, fmt.Errorf("СберЗдоровье не подключено")
	}
	from, to = from.In(moscow), to.In(moscow)
	if !to.After(from) {
		return matchOpts{}, fmt.Errorf("СберЗдоровье: некорректный период 1С")
	}
	mode := "week"
	if describeReportPeriod(from, to).Mode == "months" {
		mode = "month"
	}
	// Confirmed sample includes requests created on crDateTill: provider's end
	// date is inclusive. 1C integrations internally use an exclusive end.
	export, err := a.sberhealth.Download(ctx, from, to.AddDate(0, 0, -1), mode)
	if err != nil {
		return matchOpts{}, err
	}
	if export.Format != "xls" {
		return matchOpts{}, fmt.Errorf("СберЗдоровье: формат выгрузки изменился; ожидается проверенный бинарный XLS")
	}
	rows, err := sberhealth.ReadXLS(export.Data)
	if err != nil {
		return matchOpts{}, err
	}
	phones, records, total, err := parseSberHealthRows(rows, from, to)
	if err != nil {
		return matchOpts{}, err
	}
	info := &sberhealthSourceInfo{From: from.Format("2006-01-02"), To: to.AddDate(0, 0, -1).Format("2006-01-02"),
		Records: records, Phones: len(phones), ExportRecords: total}
	return matchOpts{pbxLists: map[string][]string{"сберздоровье": phones}, sberhealthInfo: info}, nil
}

var sberCountRE = regexp.MustCompile(`(?i)^количество\s+элементов\s*:\s*(\d+)\s*$`)

// The source sheet's schema is confirmed against Report_20261005_123725.xls:
// row 7 headers; B creation date, E phone; footer declares element count.
// All statuses/sources are retained, matching the user's -1 export filters.
// Appointment costs/prepayments never enter revenue: money comes only from 1C.
func parseSberHealthRows(rows [][]string, from, to time.Time) ([]string, int, int, error) {
	header, idCol, dateCol, phoneCol := -1, -1, -1, -1
	for i, row := range rows {
		if i >= 15 {
			break
		}
		id, date, phone := -1, -1, -1
		for j, value := range row {
			switch strings.ToLower(strings.TrimSpace(value)) {
			case "#":
				id = j
			case "дата создания записи":
				date = j
			case "телефон":
				phone = j
			}
		}
		if id >= 0 && date >= 0 && phone >= 0 {
			header, idCol, dateCol, phoneCol = i, id, date, phone
			break
		}
	}
	if header < 0 {
		return nil, 0, 0, fmt.Errorf("СберЗдоровье: нет столбцов #, Дата создания записи и Телефон")
	}
	keys, ids := map[string]bool{}, map[string]bool{}
	records, total, declared := 0, 0, -1
	footer := false
	for i := header + 1; i < len(rows); i++ {
		row := rows[i]
		id, date, phone := strings.TrimSpace(cell(row, idCol)), strings.TrimSpace(cell(row, dateCol)), strings.TrimSpace(cell(row, phoneCol))
		if strings.TrimSpace(strings.Join(row, "")) == "" {
			continue
		}
		if date == "" && phone == "" {
			if m := sberCountRE.FindStringSubmatch(id); len(m) > 0 && declared < 0 {
				declared, _ = strconv.Atoi(m[1])
				footer = true
				continue
			}
			if footer && strings.HasPrefix(strings.ToLower(id), "дата формирования отчета:") {
				continue
			}
			return nil, 0, 0, fmt.Errorf("СберЗдоровье: неизвестная служебная строка %d", i+1)
		}
		if footer {
			return nil, 0, 0, fmt.Errorf("СберЗдоровье: записи после итоговой строки")
		}
		created, err := time.ParseInLocation("02.01.2006 15:04", date, moscow)
		idNumber, idErr := strconv.ParseUint(id, 10, 64)
		if err != nil || idErr != nil || idNumber == 0 || ids[id] {
			return nil, 0, 0, fmt.Errorf("СберЗдоровье: неверная дата, номер или дубль записи в строке %d", i+1)
		}
		ids[id] = true
		total++
		if created.Before(from) || !created.Before(to) {
			continue
		}
		phones, bad := phoneKeys(phone)
		if len(phones) == 0 || bad {
			return nil, 0, 0, fmt.Errorf("СберЗдоровье: не распознан телефон в строке %d", i+1)
		}
		records++
		for _, key := range phones {
			keys[key] = true
		}
	}
	if declared < 0 || declared != total {
		return nil, 0, 0, fmt.Errorf("СберЗдоровье: число строк не совпало с «Количество элементов»; проверьте полноту выгрузки")
	}
	phones := make([]string, 0, len(keys))
	for key := range keys {
		phones = append(phones, key)
	}
	sort.Strings(phones)
	return phones, records, total, nil
}