"use client";

import { useState } from "react";
import {
  compass, dayName, formatClock, formatDuration, formatPrecip, formatShortDate, formatTemp, formatWind,
  tempValue, uvLabel, type Units,
} from "@/lib/display";
import { pixelLabel } from "@/lib/styles";
import type { DailyForecast } from "@/lib/weather/types";
import { SkyIcon } from "../PixelArt";

/**
 * The daily forecast (up to 14 days) as rows:
 *
 *   Today  Oct 21  [icon]  60%   39° ━━━━━█████━━━━ 52°
 *
 * The bar shows each day's low→high against the whole period's range,
 * so warm and cold days stand out at a glance. Tap a row for its details.
 */
export function DailyView({ daily, units, timeZone, providerLabel, maxDaysOnPlan }: {
  daily: DailyForecast[];
  units: Units;
  timeZone: string | null;
  providerLabel: string;
  maxDaysOnPlan: number;
}) {
  const [openDay, setOpenDay] = useState<string | null>(null);

  if (daily.length === 0) {
    return <p className={pixelLabel}>Daily forecast unavailable for this location.</p>;
  }

  const periodLow = Math.min(...daily.map((d) => tempValue(d.lowC, units)));
  const periodHigh = Math.max(...daily.map((d) => tempValue(d.highC, units)));
  const span = Math.max(1, periodHigh - periodLow);
  const percentAlong = (celsius: number) => ((tempValue(celsius, units) - periodLow) / span) * 100;

  return (
    <div className="flex flex-col gap-3">
      <ol className="border border-gold-dim">
        {daily.map((day) => {
          const isOpen = openDay === day.time;
          return (
            <li key={day.time} className="border-t border-gold-dim/50 first:border-t-0">
              <button
                type="button"
                aria-expanded={isOpen}
                onClick={() => setOpenDay(isOpen ? null : day.time)}
                className="grid w-full cursor-pointer grid-cols-[4.5rem_28px_2.5rem_2.25rem_1fr_2.25rem_14px] items-center gap-2 px-3 py-2.5 text-left transition-colors hover:bg-gold/6 sm:grid-cols-[7rem_32px_3rem_2.5rem_1fr_2.5rem_16px] sm:gap-3 sm:px-4"
              >
                <span className="leading-tight">
                  <span className="block font-medium">{dayName(day.time, timeZone)}</span>
                  <span className="block text-xs text-stone">{formatShortDate(day.time, timeZone)}</span>
                </span>
                <SkyIcon condition={day.condition} size={28} />
                <span className="font-pixel text-xs text-teal">
                  {day.precipChance !== null && day.precipChance >= 10 ? `${day.precipChance}%` : ""}
                </span>
                <span className="text-right font-display text-stone tabular-nums">{formatTemp(day.lowC, units)}</span>
                {/* Range bar: the gold segment spans this day's low → high */}
                <span className="relative h-1.5 bg-gold-dim/40" aria-hidden="true">
                  <span
                    className="absolute inset-y-0 bg-linear-to-r from-gold to-gold-bright"
                    style={{ left: `${percentAlong(day.lowC)}%`, right: `${100 - percentAlong(day.highC)}%` }}
                  />
                </span>
                <span className="font-display text-gold-bright tabular-nums">{formatTemp(day.highC, units)}</span>
                <span
                  aria-hidden="true"
                  className={`justify-self-end font-pixel text-xs text-stone transition-transform duration-150 ${isOpen ? "rotate-90 text-gold-bright" : ""}`}
                >
                  ›
                </span>
              </button>

              {isOpen && <DayDetails day={day} units={units} timeZone={timeZone} />}
            </li>
          );
        })}
      </ol>

      {daily.length < 14 && (
        <p className={pixelLabel}>
          {providerLabel} gives {maxDaysOnPlan} days on this plan. Choose Open-Meteo for 14.
        </p>
      )}
    </div>
  );
}

function DayDetails({ day, units, timeZone }: { day: DailyForecast; units: Units; timeZone: string | null }) {
  const wind =
    day.windKph === null
      ? null
      : `${formatWind(day.windKph, units)}${day.windDeg !== null ? ` from ${compass(day.windDeg)}` : ""}${day.gustKph ? `, gusts ${formatWind(day.gustKph, units)}` : ""}`;

  const facts: [string, string | null][] = [
    ["Precipitation", day.precipMm !== null ? `${formatPrecip(day.precipMm, units)}${day.precipChance !== null ? ` (${day.precipChance}% chance)` : ""}` : null],
    ["Wind", wind],
    ["UV index", day.uvIndexMax !== null ? `${Math.round(day.uvIndexMax)} ${uvLabel(day.uvIndexMax)}` : null],
    ["Humidity", day.humidity !== null ? `${Math.round(day.humidity)}%` : null],
    ["Sunrise", day.sunrise ? formatClock(day.sunrise, timeZone) : null],
    ["Sunset", day.sunset ? formatClock(day.sunset, timeZone) : null],
    ["Daylight", day.sunrise && day.sunset ? formatDuration(day.sunrise, day.sunset) : null],
  ];

  return (
    <div className="border-t border-gold-dim/30 bg-black px-4 pt-3 pb-4">
      {day.summary && <p className="mb-2 first-letter:uppercase">{day.summary}</p>}
      <dl className="grid grid-cols-2 gap-x-6 gap-y-2 sm:grid-cols-4">
        {facts
          .filter(([, value]) => value !== null)
          .map(([label, value]) => (
            <div key={label}>
              <dt className={pixelLabel}>{label}</dt>
              <dd className="text-sm">{value}</dd>
            </div>
          ))}
      </dl>
    </div>
  );
}