"use client";

import { useRouter, useSearchParams } from "next/navigation";
import Link from "next/link";
import { Badge } from "@/components/ui/badge";
import { Avatar, AvatarFallback, AvatarImage } from "@/components/ui/avatar";
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select";
import { cn, getInitials } from "@/lib/utils";
import {
  CalendarDays,
  ListTodo,
  AlertTriangle,
  Eye,
  Clock,
  Layers,
} from "lucide-react";
import { formatDistanceToNow } from "date-fns";
import { TASK_STATUS_CONFIG, TASK_TYPE_LABELS } from "@/components/tasks/TaskCard";
import { TaskStatus, TaskType } from "@prisma/client";

const PRIORITY_DOT: Record<string, string> = {
  LOW: "bg-zinc-500",
  NORMAL: "bg-blue-500",
  HIGH: "bg-amber-500",
  URGENT: "bg-red-500",
};

interface Artist {
  id: string;
  name: string | null;
  email: string;
}

interface Task {
  id: string;
  title: string;
  type: TaskType;
  status: TaskStatus;
  priority: string;
  dueDate: Date | null;
  shot?: { id: string; shotCode: string } | null;
  asset?: { id: string; assetCode: string; name: string } | null;
  project: { id: string; name: string; code: string };
  assignedArtist?: { id: string; name: string | null; email: string; image: string | null } | null;
  _count?: { versions: number };
  versions?: { id: string; versionNumber: number; approvalStatus: string; createdAt: Date }[];
}

interface TasksPageClientProps {
  tasks: Task[];
  artists: Artist[];
  currentUserId: string;
  role: string;
  counts: { today: number; overdue: number; inReview: number; total: number };
  activeStatus?: string;
  activeAssignee?: string;
}

const FILTER_TABS = [
  { label: "All", status: undefined, icon: ListTodo, color: "text-zinc-400" },
  { label: "Due Today", status: "today", icon: Clock, color: "text-amber-400" },
  { label: "Overdue", status: "overdue", icon: AlertTriangle, color: "text-red-400" },
  { label: "In Review", status: "INTERNAL_REVIEW", icon: Eye, color: "text-purple-400" },
];

export function TasksPageClient({
  tasks,
  artists,
  currentUserId,
  role,
  counts,
  activeStatus,
  activeAssignee,
}: TasksPageClientProps) {
  const router = useRouter();
  const isArtist = role === "ARTIST";
  const now = new Date();
  const todayStart = new Date(now.getFullYear(), now.getMonth(), now.getDate());

  // Client-side filter
  const filtered = tasks.filter((task) => {
    if (activeStatus === "today") {
      return (
        task.dueDate &&
        new Date(task.dueDate) >= todayStart &&
        new Date(task.dueDate) < new Date(todayStart.getTime() + 86400000) &&
        task.status !== "DONE"
      );
    }
    if (activeStatus === "overdue") {
      return task.dueDate && new Date(task.dueDate) < todayStart && task.status !== "DONE";
    }
    if (activeStatus === "INTERNAL_REVIEW") {
      return ["INTERNAL_REVIEW", "CLIENT_REVIEW"].includes(task.status);
    }
    return true;
  });

  const navigate = (params: { status?: string; assignee?: string }) => {
    const sp = new URLSearchParams();
    if (params.status) sp.set("status", params.status);
    if (params.assignee) sp.set("assignee", params.assignee);
    router.push(`/tasks?${sp.toString()}`);
  };

  return (
    <div className="p-6 max-w-5xl mx-auto space-y-6">
      {/* Header */}
      <div className="flex items-center justify-between">
        <div>
          <h1 className="text-2xl font-bold text-white">
            {isArtist ? "My Tasks" : "All Tasks"}
          </h1>
          <p className="text-sm text-zinc-400 mt-0.5">
            {counts.total} total · {counts.overdue > 0 && (
              <span className="text-red-400">{counts.overdue} overdue · </span>
            )}
            {counts.inReview} in review
          </p>
        </div>

        {/* Assignee filter (non-artists) */}
        {!isArtist && artists.length > 0 && (
          <Select
            value={activeAssignee ?? "__all__"}
            onValueChange={(v) =>
              navigate({ status: activeStatus, assignee: v === "__all__" ? undefined : v })
            }
          >
            <SelectTrigger className="w-44 h-8 text-sm">
              <SelectValue placeholder="All artists" />
            </SelectTrigger>
            <SelectContent>
              <SelectItem value="__all__">All artists</SelectItem>
              {artists.map((a) => (
                <SelectItem key={a.id} value={a.id}>
                  {a.name ?? a.email}
                </SelectItem>
              ))}
            </SelectContent>
          </Select>
        )}
      </div>

      {/* Filter tabs */}
      <div className="flex gap-1 border-b border-zinc-800 pb-0">
        {FILTER_TABS.map((tab) => {
          const Icon = tab.icon;
          const isActive =
            (!activeStatus && !tab.status) || activeStatus === tab.status;
          const count =
            tab.status === "today"
              ? counts.today
              : tab.status === "overdue"
              ? counts.overdue
              : tab.status === "INTERNAL_REVIEW"
              ? counts.inReview
              : counts.total;

          return (
            <button
              key={tab.label}
              onClick={() =>
                navigate({ status: tab.status, assignee: activeAssignee })
              }
              className={cn(
                "flex items-center gap-2 px-3 py-2 text-sm font-medium border-b-2 -mb-px transition-colors",
                isActive
                  ? "border-amber-500 text-amber-400"
                  : "border-transparent text-zinc-500 hover:text-zinc-300"
              )}
            >
              <Icon className={cn("h-3.5 w-3.5", isActive ? "text-amber-400" : tab.color)} />
              {tab.label}
              {count > 0 && (
                <span className="text-xs text-zinc-600 bg-zinc-800 rounded-full px-1.5 font-mono">
                  {count}
                </span>
              )}
            </button>
          );
        })}
      </div>

      {/* Task list */}
      {filtered.length === 0 ? (
        <div className="text-center py-16 border border-dashed border-zinc-800 rounded-xl">
          <ListTodo className="h-8 w-8 mx-auto mb-3 text-zinc-700" />
          <p className="text-zinc-500 text-sm">No tasks found</p>
        </div>
      ) : (
        <div className="space-y-1">
          {filtered.map((task) => {
            const cfg = TASK_STATUS_CONFIG[task.status];
            const Icon = cfg.icon;
            const contextCode = task.shot?.shotCode ?? task.asset?.assetCode;
            const isOverdue =
              task.dueDate &&
              new Date(task.dueDate) < now &&
              task.status !== "DONE";
            const latestVersion = task.versions?.[0];

            return (
              <Link
                key={task.id}
                href={`/tasks/${task.id}`}
                className="flex items-center gap-3 px-4 py-3 rounded-lg border border-transparent hover:border-zinc-800 hover:bg-zinc-900/60 transition-all group"
              >
                {/* Priority dot */}
                <span
                  className={cn(
                    "w-1.5 h-1.5 rounded-full shrink-0",
                    PRIORITY_DOT[task.priority] ?? "bg-zinc-500"
                  )}
                />

                {/* Title + context */}
                <div className="flex-1 min-w-0">
                  <div className="flex items-center gap-2">
                    <span className="text-sm font-medium text-zinc-200 group-hover:text-amber-400 transition-colors truncate">
                      {task.title}
                    </span>
                    {contextCode && (
                      <span className="text-[10px] font-mono text-zinc-500 bg-zinc-800 px-1.5 py-0.5 rounded shrink-0">
                        {contextCode}
                      </span>
                    )}
                  </div>
                  <div className="flex items-center gap-2 mt-0.5 text-[11px] text-zinc-500">
                    <span>{TASK_TYPE_LABELS[task.type]}</span>
                    <span className="text-zinc-700">·</span>
                    <span>{task.project.name}</span>
                  </div>
                </div>

                {/* Meta */}
                <div className="flex items-center gap-3 shrink-0">
                  {latestVersion && (
                    <span className="text-xs font-mono text-zinc-500">
                      v{latestVersion.versionNumber}
                    </span>
                  )}

                  {(task._count?.versions ?? 0) > 0 && (
                    <span className="flex items-center gap-1 text-[11px] text-zinc-500">
                      <Layers className="h-3 w-3" />
                      {task._count!.versions}
                    </span>
                  )}

                  {task.dueDate && (
                    <span
                      className={cn(
                        "flex items-center gap-1 text-[11px]",
                        isOverdue ? "text-red-400" : "text-zinc-500"
                      )}
                    >
                      <CalendarDays className="h-3 w-3" />
                      {formatDistanceToNow(new Date(task.dueDate), { addSuffix: true })}
                    </span>
                  )}

                  {task.assignedArtist && (
                    <Avatar className="h-5 w-5">
                      <AvatarImage src={task.assignedArtist.image ?? undefined} />
                      <AvatarFallback className="text-[8px] bg-zinc-700 text-zinc-300">
                        {getInitials(task.assignedArtist.name ?? task.assignedArtist.email)}
                      </AvatarFallback>
                    </Avatar>
                  )}

                  <Badge
                    className={cn(
                      "text-[10px] border px-1.5 py-0 h-5 gap-1",
                      cfg.color
                    )}
                  >
                    <Icon className="h-2.5 w-2.5" />
                    {cfg.label}
                  </Badge>
                </div>
              </Link>
            );
          })}
        </div>
      )}
    </div>
  );
}