"use client";

import { useMemo, useState } from "react";
import Link from "next/link";
import { useRouter } from "next/navigation";
import { CalendarDaysIcon, ChevronRightIcon, PlusIcon } from "lucide-react";
import { Item, ItemContent, ItemHeader, ItemTitle } from "@/components/ui/item";
import { Button } from "@/components/ui/button";
import { CreateSideOpDialog, type SideOpDialogOption } from "./CreateSideOpDialog";

export interface FridayCalendarMission {
  id: number;
  name: string;
  codeName: string;
  status: string;
  startDateTime: string;
  operationType: string;
  mapName: string | null;
  isOwn: boolean;
}

export interface FridayCalendarEntry {
  fridayIso: string;
  missions: FridayCalendarMission[];
}

interface FridayCalendarProps {
  entries: FridayCalendarEntry[];
  remainingSlots: number;
  maxSlots: number;
  maps: SideOpDialogOption[];
  campaigns: SideOpDialogOption[];
  modLists: SideOpDialogOption[];
}

const statusColors: Record<string, string> = {
  Concept: "bg-muted text-muted-foreground",
  Planning: "bg-muted text-muted-foreground",
  Ready: "bg-blue-500/20 text-blue-400",
  Scheduled: "bg-amber-500/20 text-amber-400",
  Active: "bg-green-500/20 text-green-400",
  Completed: "bg-emerald-500/20 text-emerald-400",
  Cancelled: "bg-red-500/20 text-red-400",
};

function formatFriday(iso: string): string {
  return new Date(iso).toLocaleDateString(undefined, {
    weekday: "long",
    month: "long",
    day: "numeric",
  });
}

function formatTime(iso: string): string {
  return new Date(iso).toLocaleTimeString(undefined, {
    hour: "2-digit",
    minute: "2-digit",
  });
}

function defaultStartForFriday(fridayIso: string): string {
  const date = new Date(fridayIso);
  date.setHours(20, 0, 0, 0);
  return date.toISOString();
}

export function FridayCalendar({
  entries,
  remainingSlots,
  maxSlots,
  maps,
  campaigns,
  modLists,
}: FridayCalendarProps) {
  const router = useRouter();
  const [scheduleFor, setScheduleFor] = useState<string | null>(null);

  const upcoming = useMemo(() => entries, [entries]);

  return (
    <div className="flex flex-col gap-6">
      <div className="flex flex-wrap items-center justify-between gap-3">
        <div>
          <h1 className="text-2xl font-bold tracking-tight">Friday Operations</h1>
          <p className="text-sm text-muted-foreground">
            Schedule and manage player-run Friday side operations. Each Friday gets Discord
            roll-call and RSVP automatically.
          </p>
        </div>
        <div className="flex items-center gap-2">
          <span
            className={`rounded-md border px-2.5 py-1 text-xs font-medium ${
              remainingSlots > 0
                ? "border-emerald-500/30 bg-emerald-500/10 text-emerald-400"
                : "border-red-500/30 bg-red-500/10 text-red-400"
            }`}
          >
            {remainingSlots > 0
              ? `You can schedule ${remainingSlots} more mission${remainingSlots === 1 ? "" : "s"}`
              : `Scheduling limit reached (${maxSlots} ahead)`}
          </span>
        </div>
      </div>

      <div className="flex flex-col gap-4">
        {upcoming.map((entry) => {
          const fridayTaken = entry.missions.some(
            (m) => m.status !== "Completed" && m.status !== "Cancelled",
          );
          const canSchedule = remainingSlots > 0 && !fridayTaken;
          return (
            <Item key={entry.fridayIso} variant="outline">
              <ItemHeader>
                <div className="flex items-center gap-2">
                  <CalendarDaysIcon className="size-4 text-muted-foreground" />
                  <ItemTitle>{formatFriday(entry.fridayIso)}</ItemTitle>
                </div>
                <Button
                  size="sm"
                  variant="outline"
                  disabled={!canSchedule}
                  onClick={() => setScheduleFor(entry.fridayIso)}
                >
                  <PlusIcon className="size-3.5" />
                  {fridayTaken ? "Taken" : "Schedule"}
                </Button>
              </ItemHeader>
              <ItemContent>
                {entry.missions.length === 0 ? (
                  <p className="text-sm text-muted-foreground">
                    Nothing scheduled yet — claim this Friday.
                  </p>
                ) : (
                  <div className="flex flex-col gap-1.5">
                    {entry.missions.map((m) => (
                      <Link
                        key={m.id}
                        href={`/intelligence/missions/${m.id}`}
                        className="group flex items-center gap-3 rounded-md p-1.5 transition-colors hover:bg-muted/50"
                      >
                        <span className="w-14 shrink-0 font-mono text-xs text-muted-foreground">
                          {formatTime(m.startDateTime)}
                        </span>
                        <div className="flex min-w-0 flex-1 flex-col">
                          <span className="truncate text-sm transition-colors group-hover:text-primary">
                            {m.name}
                          </span>
                          <span className="truncate font-mono text-[10px] text-muted-foreground">
                            {m.codeName}
                            {m.mapName ? ` · ${m.mapName}` : ""}
                            {m.isOwn ? " · yours" : ""}
                          </span>
                        </div>
                        <span
                          className={`shrink-0 rounded px-1.5 py-0.5 text-[10px] font-semibold uppercase tracking-wider ${
                            statusColors[m.status] ?? "bg-muted text-muted-foreground"
                          }`}
                        >
                          {m.status}
                        </span>
                        <ChevronRightIcon className="size-3 shrink-0 text-muted-foreground opacity-0 transition-opacity group-hover:opacity-100" />
                      </Link>
                    ))}
                  </div>
                )}
              </ItemContent>
            </Item>
          );
        })}
      </div>

      <p className="text-sm text-muted-foreground text-center">
        Fridays beyond this date are unavailable for scheduling via the web app.<br/><br/>If you want to schedule an
        op further out than the dates listed here, please contact <b>Jason (Z8MB1E)</b> directly.
      </p>

      <CreateSideOpDialog
        open={scheduleFor !== null}
        onOpenChange={(open) => {
          if (!open) setScheduleFor(null);
        }}
        maps={maps}
        campaigns={campaigns}
        modLists={modLists}
        defaultStartDateTime={scheduleFor ? defaultStartForFriday(scheduleFor) : undefined}
        onSaved={() => router.refresh()}
      />
    </div>
  );
}