<?php
/**
 * MODULE: Weather (Open-Meteo, no API key)
 * ---------------------------------------
 * Provides three actions:
 *   @weather_today Lisbon
 *   @weather_tomorrow Lisbon
 *   @weather_this_week Lisbon
 *
 * Uses Open-Meteo Geocoding + Forecast APIs (free, public).
 * Returns human-readable summaries (temps °C, precip, wind + weather emoji).
 */

// ───────────────────────────────────────────────────────────────────────────────
// 1) Register actions
// ───────────────────────────────────────────────────────────────────────────────
registerAction(
    (new Action())
        ->setFunctionName("weather_today")
        ->setArgumentsTypes(["string"]) // location
);

registerAction(
    (new Action())
        ->setFunctionName("weather_tomorrow")
        ->setArgumentsTypes(["string"]) // location
);

registerAction(
    (new Action())
        ->setFunctionName("weather_this_week")
        ->setArgumentsTypes(["string"]) // location
);

// ───────────────────────────────────────────────────────────────────────────────
// 2) Public action functions
// ───────────────────────────────────────────────────────────────────────────────

/**
 * @param string $place e.g. "Lisbon"
 * @return string
 */
function weather_today(string $place): string {
    $ctx = wm_build_context($place);
    if (isset($ctx['error'])) return $ctx['error'];

    // index 0 = today
    $i = 0;
    $d  = $ctx['daily'];
    if (!isset($d['time'][$i])) return "No forecast found for today in {$ctx['name']}.";

    $dateLabel = wm_pretty_date($d['time'][$i], $ctx['tz']);
    return wm_format_day_summary("Today in {$ctx['name']}", $dateLabel, $d, $i);
}

/**
 * @param string $place
 * @return string
 */
function weather_tomorrow(string $place): string {
    $ctx = wm_build_context($place);
    if (isset($ctx['error'])) return $ctx['error'];

    // index 1 = tomorrow
    $i = 1;
    $d  = $ctx['daily'];
    if (!isset($d['time'][$i])) return "No forecast found for tomorrow in {$ctx['name']}.";

    $dateLabel = wm_pretty_date($d['time'][$i], $ctx['tz']);
    return wm_format_day_summary("Tomorrow in {$ctx['name']}", $dateLabel, $d, $i);
}

/**
 * @param string $place
 * @return string
 */
function weather_this_week(string $place): string {
    $ctx = wm_build_context($place);
    if (isset($ctx['error'])) return $ctx['error'];

    $d = $ctx['daily'];
    if (empty($d['time'])) return "No weekly forecast found for {$ctx['name']}.";

    $lines = [];
    $lines[] = "This week in {$ctx['name']} ({$ctx['tz']}):";

    $n = min(count($d['time']), 7);
    for ($i = 0; $i < $n; $i++) {
        $date = $d['time'][$i];
        $label = wm_pretty_weekday($date, $ctx['tz']); // e.g., Mon 2025-09-15
        $lines[] = "• " . wm_format_compact_line($label, $d, $i);
    }

    return implode("\n", $lines);
}

// ───────────────────────────────────────────────────────────────────────────────
// 3) Internals
// ───────────────────────────────────────────────────────────────────────────────

/**
 * Resolve place -> lat/lon via Open-Meteo Geocoding and fetch a 7-day daily forecast.
 * @param string $place
 * @return array context with:
 *   name (City, Country), tz, daily => [keys matching Open-Meteo daily params]
 *   or ['error' => 'message']
 */
function wm_build_context(string $place): array {
    $place = trim($place);
    if ($place === '') return ['error' => "Please provide a location (e.g., 'Lisbon')."];

    $geo = wm_http_json("https://geocoding-api.open-meteo.com/v1/search?name=" . urlencode($place) . "&count=1&language=en&format=json");
    if (!$geo || empty($geo['results'][0])) {
        return ['error' => "Could not find location for '$place'."];
    }

    $g = $geo['results'][0];
    $lat = $g['latitude'];
    $lon = $g['longitude'];
    $displayName = $g['name'] . (isset($g['country']) ? ", " . $g['country'] : "");

    // Daily parameters
    $dailyParams = [
        'weathercode',
        'temperature_2m_max',
        'temperature_2m_min',
        'precipitation_sum',
        'precipitation_probability_max',
        'windspeed_10m_max'
    ];

    $forecastUrl = "https://api.open-meteo.com/v1/forecast?"
        . http_build_query([
            'latitude'  => $lat,
            'longitude' => $lon,
            'daily'     => implode(',', $dailyParams),
            'forecast_days' => 7,
            'timezone'  => 'auto'
        ]);

    $fc = wm_http_json($forecastUrl);
    if (!$fc || empty($fc['daily'])) {
        return ['error' => "Could not fetch forecast for '$displayName'."];
    }

    $tz = $fc['timezone'] ?? 'local';
    return [
        'name'  => $displayName,
        'tz'    => $tz,
        'daily' => $fc['daily'],
    ];
}

/**
 * Simple GET JSON helper with cURL
 * @param string $url
 * @return array|null
 */
function wm_http_json(string $url): ?array {
    $ch = curl_init($url);
    curl_setopt_array($ch, [
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_FOLLOWLOCATION => true,
        CURLOPT_TIMEOUT => 10,
        CURLOPT_USERAGENT => "WeatherModule/1.0 (+github.com/you)"
    ]);
    $res = curl_exec($ch);
    $err = curl_error($ch);
    curl_close($ch);

    if ($res === false || !$res) return null;
    $data = json_decode($res, true);
    return is_array($data) ? $data : null;
}

/**
 * Format a single-day verbose summary.
 */
function wm_format_day_summary(string $title, string $dateLabel, array $d, int $i): string {
    $code = $d['weathercode'][$i] ?? null;
    $desc = wm_weathercode_text($code);
    $icon = wm_weathercode_emoji($code);

    $tmax = wm_num($d['temperature_2m_max'][$i] ?? null);
    $tmin = wm_num($d['temperature_2m_min'][$i] ?? null);
    $pp   = wm_num($d['precipitation_probability_max'][$i] ?? null);
    $pr   = wm_num($d['precipitation_sum'][$i] ?? null);
    $wmax = wm_num($d['windspeed_10m_max'][$i] ?? null);

    $parts = [];
    $parts[] = "$title — $dateLabel";
    $parts[] = "$icon $desc";
    if ($tmax !== null && $tmin !== null) $parts[] = "Temp: min {$tmin}°C / max {$tmax}°C";
    if ($pp !== null) $parts[] = "Precip prob: {$pp}%";
    if ($pr !== null) $parts[] = "Precip total: {$pr} mm";
    if ($wmax !== null) $parts[] = "Wind up to: {$wmax} m/s";

    return implode("\n", $parts);
}

/**
 * Format a compact weekly line for a given day.
 */
function wm_format_compact_line(string $label, array $d, int $i): string {
    $code = $d['weathercode'][$i] ?? null;
    $icon = wm_weathercode_emoji($code);

    $tmax = wm_num($d['temperature_2m_max'][$i] ?? null);
    $tmin = wm_num($d['temperature_2m_min'][$i] ?? null);
    $pp   = wm_num($d['precipitation_probability_max'][$i] ?? null);

    $temp = ($tmin !== null && $tmax !== null) ? "{$tmin}–{$tmax}°C" : "n/a";
    $prob = ($pp !== null) ? "{$pp}%" : "n/a";

    return sprintf("%s  %s  %s  (rain prob %s)", $label, $icon, $temp, $prob);
}

/**
 * Weather code -> short text
 * Ref: https://open-meteo.com/en/docs
 */
function wm_weathercode_text(?int $code): string {
    $map = [
        0 => "Clear sky",
        1 => "Mainly clear",
        2 => "Partly cloudy",
        3 => "Overcast",
        45 => "Fog",
        48 => "Depositing rime fog",
        51 => "Light drizzle",
        53 => "Moderate drizzle",
        55 => "Dense drizzle",
        56 => "Freezing drizzle (light)",
        57 => "Freezing drizzle (dense)",
        61 => "Slight rain",
        63 => "Moderate rain",
        65 => "Heavy rain",
        66 => "Freezing rain (light)",
        67 => "Freezing rain (heavy)",
        71 => "Slight snow fall",
        73 => "Moderate snow fall",
        75 => "Heavy snow fall",
        77 => "Snow grains",
        80 => "Rain showers (slight)",
        81 => "Rain showers (moderate)",
        82 => "Rain showers (violent)",
        85 => "Snow showers (slight)",
        86 => "Snow showers (heavy)",
        95 => "Thunderstorm (slight/moderate)",
        96 => "Thunderstorm with slight hail",
        99 => "Thunderstorm with heavy hail",
    ];
    return $map[$code] ?? "Unknown conditions";
}

/**
 * Weather code -> emoji
 */
function wm_weathercode_emoji(?int $code): string {
    if ($code === null) return "🌡️";
    if ($code === 0) return "☀️";
    if (in_array($code, [1,2])) return "⛅";
    if ($code === 3) return "☁️";
    if (in_array($code, [45,48])) return "🌫️";
    if (in_array($code, [51,53,55,61,63,65,80,81,82])) return "🌧️";
    if (in_array($code, [66,67])) return "🌨️🧊";
    if (in_array($code, [71,73,75,77,85,86])) return "❄️";
    if (in_array($code, [95,96,99])) return "⛈️";
    return "🌡️";
}

/**
 * Pretty date label (e.g., 2025-09-09 → Tue 9 Sep)
 */
function wm_pretty_date(string $isoDate, string $tz): string {
    try {
        $dt = new DateTime($isoDate, new DateTimeZone($tz ?: 'UTC'));
        return $dt->format('D j M Y');
    } catch (Throwable $e) {
        return $isoDate;
    }
}

/**
 * Weekday + date (e.g., Tue 2025-09-09)
 */
function wm_pretty_weekday(string $isoDate, string $tz): string {
    try {
        $dt = new DateTime($isoDate, new DateTimeZone($tz ?: 'UTC'));
        return $dt->format('D Y-m-d');
    } catch (Throwable $e) {
        return $isoDate;
    }
}

/**
 * Round number nicely or return null
 */
function wm_num($v): ?string {
    if ($v === null) return null;
    if ($v === '' || !is_numeric($v)) return null;
    return (string)round((float)$v, 1);
}