"use client";

import { useState, useTransition, useEffect } from "react";
import Link from "next/link";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { ShotCard } from "@/components/shots/ShotCard";
import { NewShotDialog } from "@/components/shots/NewShotDialog";
import { ImportShotsDialog } from "@/components/shots/ImportShotsDialog";
import { AssetCard } from "@/components/assets/AssetCard";
import { NewAssetDialog } from "@/components/assets/NewAssetDialog";
import { TaskCard } from "@/components/tasks/TaskCard";
import { NewTaskDialog } from "@/components/tasks/NewTaskDialog";
import { KanbanBoard } from "@/components/tasks/KanbanBoard";
import { cn } from "@/lib/utils";
import { Film, Package, ListTodo, LayoutDashboard, Plus, Settings, FileUp, ChevronDown, ChevronRight, Calendar, Pencil, Check, X } from "lucide-react";
import type { ShotWithDetails } from "@/types";
import { ProjectSettingsTab } from "@/components/projects/ProjectSettingsTab";
import { setEpisodeDueDate } from "@/actions/episode-due-dates";
import { useToast } from "@/components/ui/use-toast";
import { format } from "date-fns";

type Tab = "shots" | "assets" | "tasks" | "kanban" | "settings";

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

interface Client {
  id: string;
  company: string;
}

interface TeamMember {
  id: string;
  name: string | null;
  email: string;
  role: string;
}

interface ProjectTabsClientProps {
  projectId: string;
  projectType: "STANDARD" | "EPISODIC";
  projectSettings: {
    id: string;
    name: string;
    code: string;
    showId: string;
    projectType: "STANDARD" | "EPISODIC";
    description: string | null;
    status: string;
    clientId: string | null;
    producerId: string | null;
    supervisorId: string | null;
    dueDate: Date | null;
    startDate: Date | null;
    slackWebhook: string | null;
    slackChannel: string | null;
  };
  clients: Client[];
  teamMembers: TeamMember[];
  shots: ShotWithDetails[];
  assets: any[];
  tasks: any[];
  artists: Artist[];
  shotGroups: { id: string; name: string }[];
  episodeDueDates: { episode: string; dueDate: Date | string }[];
  canManage: boolean;
}

export function ProjectTabsClient({
  projectId,
  projectType,
  projectSettings,
  clients,
  teamMembers,
  shots,
  assets,
  tasks,
  artists,
  shotGroups,
  episodeDueDates,
  canManage,
}: ProjectTabsClientProps) {
  const { toast } = useToast();
  const [activeTab, setActiveTab] = useState<Tab>("shots");
  const [showNewShot, setShowNewShot] = useState(false);
  const [showImportShots, setShowImportShots] = useState(false);
  const [showNewAsset, setShowNewAsset] = useState(false);
  const [showNewTask, setShowNewTask] = useState(false);
  const [expandedEpisodes, setExpandedEpisodes] = useState<Set<string>>(new Set());
  const [editingEpisode, setEditingEpisode] = useState<string | null>(null);

  // Load saved episode expand state from localStorage on mount
  useEffect(() => {
    try {
      const saved = localStorage.getItem(`project:${projectId}:episodeExpand`);
      if (saved) setExpandedEpisodes(new Set(JSON.parse(saved) as string[]));
    } catch {}
  }, [projectId]);
  const [episodeDateInput, setEpisodeDateInput] = useState("");
  const [isPendingDate, startDateTransition] = useTransition();

  // Build a lookup map for episode due dates
  const episodeDueDateMap = new Map(
    episodeDueDates.map((e) => [e.episode, new Date(e.dueDate)])
  );

  const handleSaveEpisodeDate = (episode: string) => {
    startDateTransition(async () => {
      try {
        await setEpisodeDueDate({
          projectId,
          episode,
          dueDate: episodeDateInput || null,
        });
        toast({ title: `Due date ${episodeDateInput ? "set" : "cleared"} for Episode ${episode}` });
      } catch {
        toast({ title: "Failed to save due date", variant: "destructive" });
      } finally {
        setEditingEpisode(null);
        setEpisodeDateInput("");
      }
    });
  };

  const toggleEpisode = (ep: string) =>
    setExpandedEpisodes((prev) => {
      const next = new Set(prev);
      next.has(ep) ? next.delete(ep) : next.add(ep);
      try {
        localStorage.setItem(`project:${projectId}:episodeExpand`, JSON.stringify([...next]));
      } catch {}
      return next;
    });

  // For episodic projects: group and sort shots by episode → scene → shotNumber
  const episodeGroups: [string, ShotWithDetails[]][] = projectType === "EPISODIC"
    ? (() => {
        const sorted = [...shots].sort((a, b) => {
          const ea = a.episode ?? "";
          const eb = b.episode ?? "";
          if (ea !== eb) return ea.localeCompare(eb, undefined, { numeric: true });
          if (a.scene !== b.scene) return a.scene.localeCompare(b.scene, undefined, { numeric: true });
          return a.shotNumber - b.shotNumber;
        });
        const map = new Map<string, ShotWithDetails[]>();
        for (const shot of sorted) {
          const key = shot.episode ?? "(No Episode)";
          if (!map.has(key)) map.set(key, []);
          map.get(key)!.push(shot);
        }
        return Array.from(map.entries());
      })()
    : [];

  // For standard projects: group by custom shot group when any exist
  const standardGroups: [string, ShotWithDetails[]][] = projectType === "STANDARD" && shots.some((s) => s.shotGroup)
    ? (() => {
        const sorted = [...shots].sort((a, b) => {
          const ga = a.shotGroup?.name ?? "\uFFFF";
          const gb = b.shotGroup?.name ?? "\uFFFF";
          if (ga !== gb) return ga.localeCompare(gb, undefined, { numeric: true });
          if (a.scene !== b.scene) return a.scene.localeCompare(b.scene, undefined, { numeric: true });
          return a.shotNumber - b.shotNumber;
        });
        const map = new Map<string, ShotWithDetails[]>();
        for (const shot of sorted) {
          const key = shot.shotGroup?.name ?? "(Ungrouped)";
          if (!map.has(key)) map.set(key, []);
          map.get(key)!.push(shot);
        }
        // Move ungrouped to the end
        const ungrouped = map.get("(Ungrouped)");
        if (ungrouped) {
          map.delete("(Ungrouped)");
          map.set("(Ungrouped)", ungrouped);
        }
        return Array.from(map.entries());
      })()
    : [];

  const tabs: { id: Tab; label: string; icon: React.ElementType; count: number; managerOnly?: boolean }[] = [
    { id: "shots", label: "Shots", icon: Film, count: shots.length },
    { id: "assets", label: "Assets", icon: Package, count: assets.length },
    { id: "tasks", label: "All Tasks", icon: ListTodo, count: tasks.length },
    { id: "kanban", label: "Kanban", icon: LayoutDashboard, count: 0 },
    { id: "settings", label: "Settings", icon: Settings, count: 0, managerOnly: true },
  ];

  const visibleTabs = tabs.filter((t) => !t.managerOnly || canManage);

  return (
    <div className="space-y-4">
      {/* Tab bar */}
      <div className="flex items-center justify-between border-b border-border pb-0">
        <div className="flex">
          {visibleTabs.map((tab) => {
            const Icon = tab.icon;
            return (
              <button
                key={tab.id}
                onClick={() => setActiveTab(tab.id)}
                className={cn(
                  "flex items-center gap-2 px-4 py-2.5 text-sm font-medium border-b-2 transition-colors -mb-px",
                  activeTab === tab.id
                    ? "border-amber-500 text-amber-400"
                    : "border-transparent text-zinc-500 hover:text-zinc-300"
                )}
              >
                <Icon className="h-4 w-4" />
                {tab.label}
                {tab.count > 0 && (
                  <span className="text-xs text-zinc-500">{tab.count}</span>
                )}
              </button>
            );
          })}
        </div>

        {/* Context-sensitive add button */}
        {canManage && (
          <div className="pb-1">
            {activeTab === "shots" && (
              <div className="flex items-center gap-2">
                <Button variant="outline" size="sm" className="gap-2 h-8" onClick={() => setShowImportShots(true)}>
                  <FileUp className="h-3.5 w-3.5" /> Import CSV
                </Button>
                <Button variant="outline" size="sm" className="gap-2 h-8" asChild>
                  <Link href={`/projects/${projectId}/import-edl`}>
                    <FileUp className="h-3.5 w-3.5" /> VFX Pull
                  </Link>
                </Button>
                <Button size="sm" className="gap-2 h-8" onClick={() => setShowNewShot(true)}>
                  <Plus className="h-3.5 w-3.5" /> New Shot
                </Button>
              </div>
            )}
            {activeTab === "assets" && (
              <Button size="sm" className="gap-2 h-8" onClick={() => setShowNewAsset(true)}>
                <Plus className="h-3.5 w-3.5" /> New Asset
              </Button>
            )}
            {(activeTab === "tasks" || activeTab === "kanban") && (
              <Button size="sm" className="gap-2 h-8" onClick={() => setShowNewTask(true)}>
                <Plus className="h-3.5 w-3.5" /> New Task
              </Button>
            )}
          </div>
        )}
      </div>

      {/* Tab content */}
      {activeTab === "shots" && (
        <div>
          {shots.length === 0 ? (
            <EmptyState icon={Film} label="No shots yet" />
          ) : projectType === "EPISODIC" ? (
            <div className="space-y-4">
              {episodeGroups.map(([episode, episodeShots]) => {
                const collapsed = !expandedEpisodes.has(episode);
                const dueDate = episodeDueDateMap.get(episode);
                const isOverdue = dueDate && dueDate < new Date();
                const isEditing = editingEpisode === episode;
                return (
                  <div key={episode}>
                    <div className="flex items-center gap-2 w-full mb-3">
                      <button
                        onClick={() => toggleEpisode(episode)}
                        className="flex items-center gap-2 shrink-0"
                      >
                        {collapsed
                          ? <ChevronRight className="h-4 w-4 text-muted-foreground" />
                          : <ChevronDown className="h-4 w-4 text-muted-foreground" />}
                      </button>
                      <button
                        onClick={() => toggleEpisode(episode)}
                        className="flex items-center gap-2 text-left"
                      >
                        <span className="font-semibold text-sm">
                          Episode {episode}
                        </span>
                        <span className="text-xs text-muted-foreground font-normal">
                          {episodeShots.length} shot{episodeShots.length !== 1 ? "s" : ""}
                        </span>
                      </button>
                      {/* Due date display / edit */}
                      {isEditing ? (
                        <div className="flex items-center gap-1 ml-2">
                          <Input
                            type="date"
                            value={episodeDateInput}
                            onChange={(e) => setEpisodeDateInput(e.target.value)}
                            className="h-6 w-36 text-xs px-2 py-0"
                          />
                          <button
                            onClick={() => handleSaveEpisodeDate(episode)}
                            disabled={isPendingDate}
                            className="text-emerald-400 hover:text-emerald-300 p-0.5"
                          >
                            <Check className="h-3.5 w-3.5" />
                          </button>
                          <button
                            onClick={() => { setEditingEpisode(null); setEpisodeDateInput(""); }}
                            className="text-zinc-500 hover:text-zinc-300 p-0.5"
                          >
                            <X className="h-3.5 w-3.5" />
                          </button>
                        </div>
                      ) : (
                        <div className="flex items-center gap-1.5 ml-2">
                          {dueDate && (
                            <span className={cn(
                              "flex items-center gap-1 text-xs",
                              isOverdue ? "text-red-400" : "text-zinc-400"
                            )}>
                              <Calendar className="h-3 w-3" />
                              {format(dueDate, "d MMM yyyy")}
                            </span>
                          )}
                          {canManage && (
                            <button
                              onClick={() => {
                                setEditingEpisode(episode);
                                setEpisodeDateInput(
                                  dueDate ? format(dueDate, "yyyy-MM-dd") : ""
                                );
                              }}
                              className="text-zinc-600 hover:text-zinc-300 p-0.5 opacity-0 group-hover:opacity-100 transition-opacity"
                              title="Set due date"
                            >
                              <Pencil className="h-3 w-3" />
                            </button>
                          )}
                        </div>
                      )}
                      <div className="flex-1 h-px bg-border ml-1" />
                      {/* Always-visible edit button for managers */}
                      {canManage && !isEditing && (
                        <button
                          onClick={() => {
                            setEditingEpisode(episode);
                            setEpisodeDateInput(
                              dueDate ? format(dueDate, "yyyy-MM-dd") : ""
                            );
                          }}
                          className="text-zinc-600 hover:text-zinc-400 transition-colors shrink-0"
                          title="Set episode due date"
                        >
                          <Pencil className="h-3 w-3" />
                        </button>
                      )}
                    </div>
                    {!collapsed && (
                      <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 xl:grid-cols-4 gap-3">
                        {episodeShots.map((shot) => (
                          <ShotCard key={shot.id} shot={shot} projectId={projectId} canManage={canManage} />
                        ))}
                      </div>
                    )}
                  </div>
                );
              })}
            </div>
          ) : standardGroups.length > 0 ? (
            <div className="space-y-4">
              {standardGroups.map(([groupName, groupShots]) => {
                const collapsed = !expandedEpisodes.has(groupName);
                return (
                  <div key={groupName}>
                    <button
                      onClick={() => toggleEpisode(groupName)}
                      className="flex items-center gap-2 w-full mb-3 group text-left"
                    >
                      {collapsed
                        ? <ChevronRight className="h-4 w-4 text-muted-foreground shrink-0" />
                        : <ChevronDown className="h-4 w-4 text-muted-foreground shrink-0" />}
                      <span className="font-semibold text-sm">{groupName}</span>
                      <span className="text-xs text-muted-foreground font-normal">
                        {groupShots.length} shot{groupShots.length !== 1 ? "s" : ""}
                      </span>
                      <div className="flex-1 h-px bg-border ml-1" />
                    </button>
                    {!collapsed && (
                      <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 xl:grid-cols-4 gap-3">
                        {groupShots.map((shot) => (
                          <ShotCard key={shot.id} shot={shot} projectId={projectId} canManage={canManage} />
                        ))}
                      </div>
                    )}
                  </div>
                );
              })}
            </div>
          ) : (
            <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 xl:grid-cols-4 gap-3">
              {shots.map((shot) => (
                <ShotCard key={shot.id} shot={shot} projectId={projectId} canManage={canManage} />
              ))}
            </div>
          )}
        </div>
      )}

      {activeTab === "assets" && (
        <div className="space-y-2">
          {assets.length === 0 ? (
            <EmptyState icon={Package} label="No assets yet" />
          ) : (
            assets.map((asset) => (
              <AssetCard
                key={asset.id}
                asset={asset}
                projectId={projectId}
                artists={artists}
                canManage={canManage}
              />
            ))
          )}
        </div>
      )}

      {activeTab === "tasks" && (
        <div className="space-y-1">
          {tasks.length === 0 ? (
            <EmptyState icon={ListTodo} label="No tasks yet" />
          ) : (
            tasks.map((task) => (
              <TaskCard key={task.id} task={task} projectId={projectId} canManage={canManage} />
            ))
          )}
        </div>
      )}

      {activeTab === "kanban" && (
        <KanbanBoard tasks={tasks} projectId={projectId} artists={artists} />
      )}

      {activeTab === "settings" && canManage && (
        <ProjectSettingsTab
          project={projectSettings}
          clients={clients}
          teamMembers={teamMembers}
        />
      )}

      {/* Dialogs */}
      <NewShotDialog
        projectId={projectId}
        projectType={projectType}
        shotGroups={shotGroups}
        open={showNewShot}
        onClose={() => setShowNewShot(false)}
        onSuccess={() => setShowNewShot(false)}
      />
      <ImportShotsDialog
        projectId={projectId}
        projectType={projectType}
        open={showImportShots}
        onClose={() => setShowImportShots(false)}
        onSuccess={() => setShowImportShots(false)}
      />
      <NewAssetDialog
        projectId={projectId}
        open={showNewAsset}
        onClose={() => setShowNewAsset(false)}
        onSuccess={() => setShowNewAsset(false)}
      />
      <NewTaskDialog
        projectId={projectId}
        artists={artists}
        open={showNewTask}
        onClose={() => setShowNewTask(false)}
        onSuccess={() => setShowNewTask(false)}
      />
    </div>
  );
}

function EmptyState({ icon: Icon, label }: { icon: React.ElementType; label: string }) {
  return (
    <div className="text-center py-10 text-muted-foreground border border-dashed border-border rounded-lg">
      <Icon className="h-8 w-8 mx-auto mb-3 opacity-30" />
      <p className="text-sm">{label}</p>
    </div>
  );
}