package service

import (
	"context"
	"encoding/csv"
	"fmt"
	"io"
	"log"
	"strings"

	"bugulma/backend/internal/domain"
)

// ImportPublicTransportData imports stops and routes from the service's loaded files into repository
func ImportPublicTransportData(ctx context.Context, svc *PublicTransportService, repo domain.PublicTransportRepository) error {
	if svc == nil || repo == nil {
		return nil // nothing to do
	}

	// Seed common stops from enriched JSON if available
	if cs := svc.ListStops(); len(cs) > 0 {
		for key, v := range cs {
			m, ok := v.(map[string]interface{})
			if !ok {
				continue
			}
			stop := &domain.PublicTransportStop{ID: key}
			if name, ok := m["name"].(string); ok {
				stop.Name = name
			}
			if nameEn, ok := m["name_en"].(string); ok {
				stop.NameEn = nameEn
			}
			if typ, ok := m["type"].(string); ok {
				stop.Type = typ
			}
			if addr, ok := m["address"].(string); ok {
				stop.Address = addr
			}
			if osm, ok := m["osm_id"].(string); ok {
				stop.OsmID = osm
			}
			if est, ok := m["estimated"].(bool); ok {
				stop.Estimated = est
			}
			if loc, ok := m["location"].(map[string]interface{}); ok {
				if lat, ok := loc["lat"].(float64); ok {
					stop.Latitude = &lat
				}
				if lng, ok := loc["lng"].(float64); ok {
					stop.Longitude = &lng
				}
			}
			if routes, ok := m["routes_served"].([]interface{}); ok {
				for _, r := range routes {
					if s, ok := r.(string); ok {
						stop.RoutesServed = append(stop.RoutesServed, s)
					}
				}
			}

			if err := repo.UpsertStop(ctx, stop); err != nil {
				log.Printf("warning: failed to upsert stop %s: %v", stop.ID, err)
			}
		}
	}

	// Seed GTFS routes from routes.txt
	if routesCSV, err := svc.ReadGTFSFile("routes.txt"); err == nil {
		r := csv.NewReader(strings.NewReader(routesCSV))
		// Read header
		header, err := r.Read()
		if err == nil {
			idx := map[string]int{}
			for i, h := range header {
				idx[h] = i
			}
			for {
				rec, err := r.Read()
				if err == io.EOF {
					break
				}
				if err != nil {
					return fmt.Errorf("failed to read routes CSV: %w", err)
				}
				id := rec[idx["route_id"]]
				rt := &domain.PublicTransportRoute{ID: id}
				if v, ok := idx["agency_id"]; ok {
					rt.AgencyID = rec[v]
				}
				if v, ok := idx["route_short_name"]; ok {
					rt.ShortName = rec[v]
				}
				if v, ok := idx["route_long_name"]; ok {
					rt.LongName = rec[v]
				}
				if v, ok := idx["route_type"]; ok {
					if rec[v] != "" {
						// parse int route_type
						// we keep it simple and ignore parse errors
						var rtType int
						fmt.Sscanf(rec[v], "%d", &rtType)
						rt.RouteType = rtType
					}
				}
				if err := repo.UpsertRoute(ctx, rt); err != nil {
					log.Printf("warning: failed to upsert route %s: %v", rt.ID, err)
				}
			}
		}
	} else {
		// Missing routes file is fine
	}

	return nil
}