package shunyunbao

import (
	"context"
	"encoding/json"
	"reflect"
	"strconv"

	"cmroubao/backend-api/internal/domain"
)

const (
	sourcePageSize   = 20
	sourceMaxMatches = 100
)

// QueryOrder implements the freight source port using the manager's single
// in-memory ERP session. It never exposes the ERP list or detail responses.
func (manager *SessionManager) QueryOrder(
	ctx context.Context,
	orderNumber string,
) (domain.FreightSourceBatch, error) {
	query, err := OrderNumberQuery(orderNumber)
	if err != nil {
		return domain.FreightSourceBatch{}, domain.ErrFreightSourceProtocol
	}
	records, err := manager.queryRecords(ctx, query)
	if err != nil {
		return domain.FreightSourceBatch{}, err
	}
	if len(records) == 0 {
		return domain.FreightSourceBatch{}, domain.ErrFreightSourceNotFound
	}
	return NormalizeFreightResult(
		RawQuery{Mode: domain.FreightSyncOrderNumber},
		records,
	)
}

// QueryCreatedRange implements the bounded Asia/Shanghai date-window source
// port. The caller owns larger-window splitting and watermark semantics.
func (manager *SessionManager) QueryCreatedRange(
	ctx context.Context,
	createdFrom, createdTo string,
) (domain.FreightSourceBatch, error) {
	query, err := CreatedRangeQuery(createdFrom, createdTo)
	if err != nil {
		return domain.FreightSourceBatch{}, domain.ErrFreightSourceProtocol
	}
	records, err := manager.queryRecords(ctx, query)
	if err != nil {
		return domain.FreightSourceBatch{}, err
	}
	return NormalizeFreightResult(
		RawQuery{
			Mode:        domain.FreightSyncCreatedRange,
			CreatedFrom: createdFrom,
			CreatedTo:   createdTo,
		},
		records,
	)
}

func (manager *SessionManager) queryRecords(
	ctx context.Context,
	query QueryCondition,
) ([]RawRecord, error) {
	manager.mu.Lock()
	defer manager.mu.Unlock()
	if !manager.configuredLocked() {
		return nil, domain.ErrFreightSourceNotConfigured
	}
	if !manager.authenticated {
		return nil, domain.ErrFreightSourceSessionNeeded
	}
	if _, err := manager.validateLocked(ctx); err != nil {
		return nil, err
	}
	stocks, err := manager.queryStocksLocked(ctx, query)
	if err != nil {
		return nil, err
	}
	if len(stocks) == 0 {
		return []RawRecord{}, nil
	}
	details, err := manager.queryDetailsLocked(ctx, stocks)
	if err != nil {
		return nil, err
	}
	records := make([]RawRecord, 0, len(stocks))
	for _, stock := range stocks {
		stockID, err := sourceExternalID(stock["id"])
		if err != nil {
			return nil, domain.ErrFreightSourceProtocol
		}
		detail, exists := details[stockID]
		if !exists {
			return nil, domain.ErrFreightSourceProtocol
		}
		records = append(records, RawRecord{Stock: stock, Detail: detail})
	}
	return records, nil
}

func (manager *SessionManager) queryStocksLocked(
	ctx context.Context,
	query QueryCondition,
) ([]map[string]any, error) {
	firstPayload, err := StockListPayload(query, 0, 1, sourcePageSize)
	if err != nil {
		return nil, domain.ErrFreightSourceProtocol
	}
	firstBody, err := json.Marshal(firstPayload)
	if err != nil {
		return nil, domain.ErrFreightSourceProtocol
	}
	totalData, err := manager.requestJSONLocked(
		ctx,
		"POST",
		StockListTotalPath,
		firstBody,
		false,
	)
	if err != nil {
		return nil, err
	}
	total, err := sourceTotal(totalData)
	if err != nil || total > sourceMaxMatches {
		return nil, domain.ErrFreightSourceProtocol
	}
	if total == 0 {
		return []map[string]any{}, nil
	}

	rows := make([]map[string]any, 0, total)
	for start := 0; start < total; start += sourcePageSize {
		payload, err := StockListPayload(
			query,
			start,
			start/sourcePageSize+1,
			sourcePageSize,
		)
		if err != nil {
			return nil, domain.ErrFreightSourceProtocol
		}
		body, err := json.Marshal(payload)
		if err != nil {
			return nil, domain.ErrFreightSourceProtocol
		}
		data, err := manager.requestJSONLocked(
			ctx,
			"POST",
			StockListPath,
			body,
			false,
		)
		if err != nil {
			return nil, err
		}
		page, err := sourceObjectList(data)
		if err != nil || len(page) > sourcePageSize {
			return nil, domain.ErrFreightSourceProtocol
		}
		rows = append(rows, page...)
	}
	if len(rows) != total {
		return nil, domain.ErrFreightSourceProtocol
	}
	stocksByID := make(map[string]map[string]any, len(rows))
	stocks := make([]map[string]any, 0, len(rows))
	for _, stock := range rows {
		stockID, err := sourceExternalID(stock["id"])
		if err != nil {
			return nil, domain.ErrFreightSourceProtocol
		}
		if existing, exists := stocksByID[stockID]; exists {
			if !reflect.DeepEqual(existing, stock) {
				return nil, domain.ErrFreightSourceProtocol
			}
			continue
		}
		stocksByID[stockID] = stock
		stocks = append(stocks, stock)
	}
	return stocks, nil
}

func (manager *SessionManager) queryDetailsLocked(
	ctx context.Context,
	stocks []map[string]any,
) (map[string]map[string]any, error) {
	ids := make([]string, 0, len(stocks))
	for _, stock := range stocks {
		stockID, err := sourceExternalID(stock["id"])
		if err != nil {
			return nil, domain.ErrFreightSourceProtocol
		}
		ids = append(ids, stockID)
	}
	detailsByID := make(map[string]map[string]any, len(ids))
	requestedIDs := make(map[string]struct{}, len(ids))
	for _, id := range ids {
		requestedIDs[id] = struct{}{}
	}
	for start := 0; start < len(ids); start += maxDetailIDs {
		end := start + maxDetailIDs
		if end > len(ids) {
			end = len(ids)
		}
		payload, err := StockDetailPayload(ids[start:end])
		if err != nil {
			return nil, domain.ErrFreightSourceProtocol
		}
		body, err := json.Marshal(payload)
		if err != nil {
			return nil, domain.ErrFreightSourceProtocol
		}
		data, err := manager.requestJSONLocked(
			ctx,
			"POST",
			StockDetailPath+"?hist=0",
			body,
			false,
		)
		if err != nil {
			return nil, err
		}
		values, err := sourceObjectList(data)
		if err != nil {
			return nil, domain.ErrFreightSourceProtocol
		}
		for _, detail := range values {
			detailID, err := sourceExternalID(detail["id"])
			if err != nil {
				return nil, domain.ErrFreightSourceProtocol
			}
			if _, requested := requestedIDs[detailID]; !requested {
				return nil, domain.ErrFreightSourceProtocol
			}
			if existing, exists := detailsByID[detailID]; exists &&
				!reflect.DeepEqual(existing, detail) {
				return nil, domain.ErrFreightSourceProtocol
			}
			detailsByID[detailID] = detail
		}
	}
	if len(detailsByID) != len(ids) {
		return nil, domain.ErrFreightSourceProtocol
	}
	return detailsByID, nil
}

func sourceTotal(value any) (int, error) {
	var text string
	switch typed := value.(type) {
	case json.Number:
		text = string(typed)
	case string:
		text = typed
	default:
		return 0, strconv.ErrSyntax
	}
	parsed, err := strconv.ParseInt(text, 10, 0)
	if err != nil || parsed < 0 || parsed > int64(sourceMaxMatches) {
		return 0, strconv.ErrSyntax
	}
	return int(parsed), nil
}

func sourceObjectList(value any) ([]map[string]any, error) {
	data, ok := value.(map[string]any)
	if !ok {
		return nil, strconv.ErrSyntax
	}
	rawList, ok := data["list"].([]any)
	if !ok {
		return nil, strconv.ErrSyntax
	}
	result := make([]map[string]any, 0, len(rawList))
	for _, value := range rawList {
		row, ok := value.(map[string]any)
		if !ok {
			return nil, strconv.ErrSyntax
		}
		result = append(result, row)
	}
	return result, nil
}

func sourceExternalID(value any) (string, error) {
	return externalID(value)
}