"use client";

/**
 * MobileWaterHeadgateList — headgate selection screen.
 *
 * Visual structure (Apple HIG grouped list):
 *   - Sticky top nav: small back chevron + "Headgates" title +
 *     logout icon on the right.
 *   - Section header ("ACTIVE HEADGATES") with a count chip.
 *   - One tappable card per headgate. Each card has:
 *       - Leading gauge icon (status-tinted)
 *       - Bold headgate name
 *       - Subtitle = "geocode" (notes) OR a derived status line
 *       - Meta row = unit + last-logged relative time
 *       - Trailing chevron
 *       - Subtle threshold badge if high/low thresholds are set
 *   - Pull-to-refresh at the top.
 *   - "No active headgates" empty state with an icon and CTA back to
 *     refresh when the operator has just added a gate.
 */
import { useCallback } from "react";
import type { FieldHeadgate } from "./types";
import {
  ChevronRight,
  Droplet,
  Gauge,
  Logout,
  Pin,
  Spinner,
} from "./icons";
import { MobilePullToRefresh } from "./PullToRefresh";
import { formatRelativeTime, headgateSubtitle } from "./format";

type Props = {
  /** Optional display name of the logged-in irrigator (for the header). */
  irrigatorName?: string;
  headgates: FieldHeadgate[];
  loading: boolean;
  error: string | null;
  onSelect: (headgate: FieldHeadgate) => void;
  onRefresh: () => Promise<void> | void;
  onLogout: () => void;
};

export function MobileWaterHeadgateList({
  irrigatorName,
  headgates,
  loading,
  error,
  onSelect,
  onRefresh,
  onLogout,
}: Props) {
  const active = headgates.filter((h) => h.active);

  return (
    <div
      className="flex h-full flex-col bg-[#F2F2F7]"
      style={{
        paddingTop: "env(safe-area-inset-top)",
      }}
    >
      {/* ── Top nav ──────────────────────────────────────────────── */}
      <header
        className="sticky top-0 z-30 flex h-11 items-center justify-between border-b border-[rgba(60,60,67,0.12)] bg-[rgba(255,255,255,0.85)] px-2"
        style={{
          paddingTop: "env(safe-area-inset-top)",
          height: "calc(44px + env(safe-area-inset-top))",
          backdropFilter: "blur(20px) saturate(180%)",
          WebkitBackdropFilter: "blur(20px) saturate(180%)",
        }}
      >
        <div className="flex items-center gap-1">
          {/* Placeholder to keep the title centered — the back
            *  chevron would lead to the PIN screen, which the user
            *  got here from. Leaving it as just the title to keep
            *  the nav minimal per HIG. */}
          <span className="w-9" />
        </div>
        <h1
          className="absolute left-1/2 -translate-x-1/2 text-[17px] font-semibold text-[#1d1d1f]"
          style={{
            fontFamily:
              "-apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', Roboto, sans-serif",
          }}
        >
          Headgates
        </h1>
        <button
          type="button"
          onClick={onLogout}
          aria-label="Sign out"
          className="flex h-9 w-9 items-center justify-center rounded-full text-[#14532d] active:bg-[rgba(120,120,128,0.16)]"
        >
          <Logout size={20} />
        </button>
      </header>

      {/* ── Scrollable list ─────────────────────────────────────── */}
      <MobilePullToRefresh onRefresh={onRefresh} disabled={loading}>
        <div className="px-4 pb-[max(env(safe-area-inset-bottom),1.25rem)] pt-3">
          {irrigatorName && (
            <p className="mb-4 px-1 text-[13px] font-medium uppercase tracking-[0.08em] text-[rgba(60,60,67,0.5)]">
              Signed in as {irrigatorName}
            </p>
          )}

          {/* Error banner */}
          {error && (
            <div
              role="alert"
              className="mb-3 flex items-start gap-2 rounded-[12px] bg-[rgba(255,59,48,0.10)] px-4 py-3 text-[15px] text-[#7f1d1d]"
            >
              <span className="mt-0.5">⚠️</span>
              <span>{error}</span>
            </div>
          )}

          {/* Section header */}
          <div className="mb-2 flex items-end justify-between px-3 pt-1">
            <h2 className="text-[13px] font-semibold uppercase tracking-[0.06em] text-[rgba(60,60,67,0.55)]">
              Active headgates
            </h2>
            <span className="text-[13px] font-medium text-[rgba(60,60,67,0.45)]">
              {active.length}
            </span>
          </div>

          {loading && active.length === 0 ? (
            <ListSkeleton />
          ) : active.length === 0 ? (
            <EmptyState onRefresh={onRefresh} refreshing={loading} />
          ) : (
            <ul className="overflow-hidden rounded-[14px] bg-white shadow-[0_1px_2px_rgba(0,0,0,0.04),0_1px_0_rgba(0,0,0,0.02)]">
              {active.map((hg, i) => (
                <li key={hg.id}>
                  <HeadgateCard
                    headgate={hg}
                    isLast={i === active.length - 1}
                    onClick={() => onSelect(hg)}
                  />
                </li>
              ))}
            </ul>
          )}

          {/* Footer note */}
          {active.length > 0 && (
            <p className="mt-4 px-3 text-center text-[12px] text-[rgba(60,60,67,0.4)]">
              Pull down to refresh the list
            </p>
          )}
        </div>
      </MobilePullToRefresh>
    </div>
  );
}

// ── Headgate card ────────────────────────────────────────────────────────

function HeadgateCard({
  headgate,
  isLast,
  onClick,
}: {
  headgate: FieldHeadgate;
  isLast: boolean;
  onClick: () => void;
}) {
  const subtitle = headgateSubtitle(headgate);
  const lastUsed = formatRelativeTime(headgate.last_used_at);
  const isClosed = headgate.status === "closed";
  const isMaintenance = headgate.status === "maintenance";

  return (
    <button
      type="button"
      onClick={onClick}
      disabled={isClosed || isMaintenance}
      className={[
        "group flex w-full items-center gap-3 px-4 py-4 text-left transition-colors",
        "active:bg-[rgba(120,120,128,0.12)]",
        isClosed || isMaintenance ? "opacity-55" : "",
      ].join(" ")}
      style={{
        borderBottom: isLast ? "none" : "1px solid rgba(60,60,67,0.10)",
        minHeight: 76,
      }}
    >
      {/* Leading icon — colored by status */}
      <div
        className="flex h-11 w-11 shrink-0 items-center justify-center rounded-[10px]"
        style={{
          background: isMaintenance
            ? "rgba(255,149,0,0.14)"
            : isClosed
              ? "rgba(120,120,128,0.14)"
              : "rgba(20,83,45,0.10)",
          color: isMaintenance
            ? "#a16207"
            : isClosed
              ? "#86868b"
              : "#14532d",
        }}
      >
        <Gauge size={22} />
      </div>

      {/* Body — name + subtitle + meta */}
      <div className="min-w-0 flex-1">
        <div className="flex items-center gap-2">
          <span
            className="truncate text-[17px] font-semibold leading-[1.2] text-[#1d1d1f]"
            style={{
              fontFamily:
                "-apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', Roboto, sans-serif",
            }}
          >
            {headgate.name}
          </span>
          {(headgate.high_threshold != null ||
            headgate.low_threshold != null) && (
            <ThresholdDot
              high={headgate.high_threshold}
              low={headgate.low_threshold}
            />
          )}
        </div>
        <div className="mt-0.5 flex items-center gap-1.5 text-[13px] text-[rgba(60,60,67,0.6)]">
          <Pin size={13} className="shrink-0 opacity-60" />
          <span className="truncate">{subtitle}</span>
        </div>
        <div className="mt-1 flex items-center gap-2 text-[12px] text-[rgba(60,60,67,0.45)]">
          <span className="rounded-full bg-[rgba(120,120,128,0.12)] px-2 py-0.5 font-medium">
            {headgate.unit}
          </span>
          <span>·</span>
          <span>{lastUsed}</span>
        </div>
      </div>

      {/* Trailing chevron */}
      <ChevronRight size={18} className="shrink-0 text-[rgba(60,60,67,0.3)]" />
    </button>
  );
}

// ── Threshold dot (small indicator on the card row) ────────────────────

function ThresholdDot({
  high,
}: {
  high: number | null;
  low: number | null;
}) {
  return (
    <span
      className="flex shrink-0 items-center gap-0.5 rounded-full px-1.5 py-0.5 text-[10px] font-bold uppercase tracking-wide"
      style={{
        background: high != null ? "rgba(255,59,48,0.12)" : "rgba(0,122,255,0.12)",
        color: high != null ? "#7f1d1d" : "#1e3a8a",
      }}
    >
      {high != null ? "Hi" : "Lo"}
    </span>
  );
}

// ── Skeleton ────────────────────────────────────────────────────────────

function ListSkeleton() {
  return (
    <ul className="overflow-hidden rounded-[14px] bg-white shadow-[0_1px_2px_rgba(0,0,0,0.04),0_1px_0_rgba(0,0,0,0.02)]">
      {[0, 1, 2, 3].map((i) => (
        <li
          key={i}
          className="flex animate-pulse items-center gap-3 px-4 py-4"
          style={{
            borderBottom: i === 3 ? "none" : "1px solid rgba(60,60,67,0.10)",
          }}
        >
          <div className="h-11 w-11 rounded-[10px] bg-[rgba(120,120,128,0.16)]" />
          <div className="flex-1 space-y-2">
            <div className="h-4 w-2/3 rounded bg-[rgba(120,120,128,0.16)]" />
            <div className="h-3 w-1/2 rounded bg-[rgba(120,120,128,0.12)]" />
          </div>
        </li>
      ))}
    </ul>
  );
}

// ── Empty state ─────────────────────────────────────────────────────────

function EmptyState({
  onRefresh,
  refreshing,
}: {
  onRefresh: () => Promise<void> | void;
  refreshing: boolean;
}) {
  const handleRefresh = useCallback(async () => {
    if (!refreshing) await onRefresh();
  }, [onRefresh, refreshing]);

  return (
    <div className="rounded-[14px] bg-white px-6 py-12 text-center shadow-[0_1px_2px_rgba(0,0,0,0.04),0_1px_0_rgba(0,0,0,0.02)]">
      <div className="mx-auto mb-4 flex h-16 w-16 items-center justify-center rounded-full bg-[rgba(20,83,45,0.10)]">
        <Droplet size={28} className="text-[#14532d]" />
      </div>
      <h3 className="mb-1 text-[17px] font-semibold text-[#1d1d1f]">
        No active headgates
      </h3>
      <p className="mx-auto mb-5 max-w-xs text-[15px] leading-[1.4] text-[rgba(60,60,67,0.6)]">
        Once your supervisor activates a headgate, it&apos;ll show up here.
        Pull down to check for updates.
      </p>
      <button
        type="button"
        onClick={handleRefresh}
        disabled={refreshing}
        className="inline-flex h-11 items-center justify-center gap-2 rounded-[10px] bg-[#14532d] px-5 text-[15px] font-semibold text-white active:opacity-80 disabled:opacity-60"
        style={{
          boxShadow: "0 4px 12px rgba(20,83,45,0.25)",
        }}
      >
        {refreshing ? (
          <>
            <Spinner size={16} className="text-white" style={{ animation: "spin 0.8s linear infinite" }} />
            Checking…
          </>
        ) : (
          "Refresh"
        )}
      </button>
    </div>
  );
}

export default MobileWaterHeadgateList;