package main

import (
	"fmt"
	"io"
	"net/http"
	"time"
)

const BaseURL = "https://www.nationalrail.co.uk/live-trains/departures/"

// FetchStationDepartures fetches the HTML content for a station's departures
func FetchStationDepartures(stationCode string) (string, error) {
	client := &http.Client{
		Timeout: 30 * time.Second,
	}

	url := BaseURL + stationCode + "/"
	req, err := http.NewRequest("GET", url, nil)
	if err != nil {
		return "", fmt.Errorf("failed to create request: %w", err)
	}

	// Add headers to mimic a browser request
	req.Header.Set("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36")
	req.Header.Set("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8")

	resp, err := client.Do(req)
	if err != nil {
		return "", fmt.Errorf("failed to fetch data: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return "", fmt.Errorf("unexpected status code: %d", resp.StatusCode)
	}

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return "", fmt.Errorf("failed to read response body: %w", err)
	}

	return string(body), nil
}

type StationData struct {
	Station    Station     `json:"station"`
	Departures []Departure `json:"departures"`
	LastUpdate time.Time   `json:"last_update"`
	Error      string      `json:"error,omitempty"`
}

// FetchAllStationsData fetches departure data for all configured stations
func FetchAllStationsData(stations []Station) []StationData {
	results := make([]StationData, len(stations))

	for i, station := range stations {
		results[i] = StationData{
			Station:    station,
			LastUpdate: time.Now(),
		}

		htmlContent, err := FetchStationDepartures(station.Code)
		if err != nil {
			results[i].Error = err.Error()
			continue
		}

		departures, err := ParseDeparturesFromHTML(htmlContent)
		if err != nil {
			results[i].Error = err.Error()
			continue
		}

		results[i].Departures = departures
	}

	return results
}