"use client";

import {
  completeTaskRecord,
  createTaskRecord,
  deleteTaskRecord,
  updateTaskStatusRecord,
  updateTaskRecord,
} from "@/app/(dashboard)/tasks/actions";
import { Badge, Button, Card, CardContent, Input, Label, Textarea } from "poyraz-ui/atoms";
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
  DialogTrigger,
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "poyraz-ui/molecules";
import {
  CalendarDays,
  CheckCircle2,
  KanbanSquare,
  LayoutList,
  Pencil,
  Plus,
  Trash2,
} from "lucide-react";
import { useEffect, useState, useTransition, type DragEvent } from "react";

export type TaskRelationOption = {
  id: string;
  name: string;
  client_id?: string | null;
};

export type TaskListItem = {
  id: string;
  title: string;
  description: string | null;
  status: "todo" | "in_progress" | "done";
  priority: "low" | "medium" | "high" | "urgent";
  due_at: string | null;
  estimated_minutes: number | null;
  actual_minutes: number | null;
  client_id: string | null;
  clientName: string | null;
  project_id: string | null;
  projectName: string | null;
  created_at: string;
};

const statusLabels = {
  todo: "Yapılacak",
  in_progress: "Devam ediyor",
  done: "Tamamlandı",
};

const priorityLabels = {
  low: "Düşük",
  medium: "Orta",
  high: "Yüksek",
  urgent: "Acil",
};

const priorityClasses = {
  low: "border-zinc-200 bg-zinc-50 text-zinc-700",
  medium: "border-blue-200 bg-blue-50 text-blue-700",
  high: "border-amber-200 bg-amber-50 text-amber-700",
  urgent: "border-rose-200 bg-rose-50 text-rose-700",
};

type TasksClientProps = {
  tasks: TaskListItem[];
  clients: TaskRelationOption[];
  projects: TaskRelationOption[];
};

export function TasksClient({ tasks, clients, projects }: TasksClientProps) {
  const [localTasks, setLocalTasks] = useState(tasks);
  const [query, setQuery] = useState("");
  const [projectFilter, setProjectFilter] = useState("__all");
  const [view, setView] = useState<"list" | "kanban">("list");
  const [, startTransition] = useTransition();

  useEffect(() => {
    setLocalTasks(tasks);
  }, [tasks]);

  function handleTaskStatusChange(taskId: string, status: TaskListItem["status"]) {
    const previousTasks = localTasks;

    setLocalTasks((currentTasks) =>
      currentTasks.map((task) => (task.id === taskId ? { ...task, status } : task)),
    );

    startTransition(() => {
      void updateTaskStatusRecord(taskId, status).catch(() => {
        setLocalTasks(previousTasks);
      });
    });
  }

  const normalizedQuery = query.trim().toLowerCase();
  const filteredByProject =
    projectFilter === "__all"
      ? localTasks
      : projectFilter === "__none"
        ? localTasks.filter((task) => !task.project_id)
        : localTasks.filter((task) => task.project_id === projectFilter);
  const filteredTasks = normalizedQuery
    ? filteredByProject.filter((task) =>
        [task.title, task.description, task.clientName, task.projectName]
          .filter(Boolean)
          .some((value) => value!.toLowerCase().includes(normalizedQuery)),
      )
    : filteredByProject;

  const doneCount = localTasks.filter((task) => task.status === "done").length;
  const overdueCount = localTasks.filter((task) => isOverdue(task)).length;
  const urgentCount = localTasks.filter((task) => task.priority === "urgent").length;

  return (
    <div className="mx-auto flex max-w-7xl flex-col gap-6">
      <div className="flex flex-col gap-4 border-b border-border pb-5 lg:flex-row lg:items-end lg:justify-between">
        <div className="space-y-2">
          <div className="flex items-center gap-2 text-sm text-muted-foreground">
            <CheckCircle2 className="h-4 w-4" />
            Günlük operasyon
          </div>
          <div>
            <h1 className="text-3xl font-semibold tracking-normal text-foreground">
              Görevler
            </h1>
            <p className="mt-1 max-w-2xl text-sm text-muted-foreground">
              Proje ve müşteri bağlantılı işleri liste veya basit kanban ile takip et.
            </p>
          </div>
        </div>

        <TaskDialog mode="create" clients={clients} projects={projects} />
      </div>

      <div className="grid gap-3 md:grid-cols-4">
        <StatCard label="Toplam görev" value={localTasks.length.toString()} />
        <StatCard label="Tamamlanan" value={doneCount.toString()} />
        <StatCard label="Geciken" value={overdueCount.toString()} />
        <StatCard label="Acil" value={urgentCount.toString()} />
      </div>

      <Card>
        <CardContent className="space-y-4 p-4">
          <div className="flex flex-col gap-3 lg:flex-row lg:items-center lg:justify-between">
            <div>
              <h2 className="text-base font-semibold text-foreground">Görev listesi</h2>
              <p className="text-sm text-muted-foreground">
                {filteredTasks.length} kayıt görüntüleniyor.
              </p>
            </div>
            <div className="flex flex-col gap-2 sm:flex-row">
              <Input
                value={query}
                onChange={(event) => setQuery(event.target.value)}
                placeholder="Görev, proje veya müşteri ara"
                className="sm:w-80"
              />
              <Select value={projectFilter} onValueChange={setProjectFilter}>
                <SelectTrigger className="sm:w-56">
                  <SelectValue placeholder="Proje filtrele" />
                </SelectTrigger>
                <SelectContent>
                  <SelectItem value="__all">Tüm projeler</SelectItem>
                  <SelectItem value="__none">Projesiz görevler</SelectItem>
                  {projects.map((project) => (
                    <SelectItem key={project.id} value={project.id}>
                      {project.name}
                    </SelectItem>
                  ))}
                </SelectContent>
              </Select>
              <div className="flex rounded-sm border border-border p-1">
                <Button
                  type="button"
                  variant={view === "list" ? "default" : "ghost"}
                  className="h-8 gap-2 px-3"
                  onClick={() => setView("list")}
                >
                  <LayoutList className="h-4 w-4" />
                  Liste
                </Button>
                <Button
                  type="button"
                  variant={view === "kanban" ? "default" : "ghost"}
                  className="h-8 gap-2 px-3"
                  onClick={() => setView("kanban")}
                >
                  <KanbanSquare className="h-4 w-4" />
                  Kanban
                </Button>
              </div>
            </div>
          </div>

          {filteredTasks.length > 0 ? (
            view === "list" ? (
              <TaskList tasks={filteredTasks} clients={clients} projects={projects} />
            ) : (
              <TaskKanban
                tasks={filteredTasks}
                clients={clients}
                projects={projects}
                onTaskStatusChange={handleTaskStatusChange}
              />
            )
          ) : (
            <EmptyState hasQuery={Boolean(normalizedQuery)} />
          )}
        </CardContent>
      </Card>
    </div>
  );
}

function TaskList({
  tasks,
  clients,
  projects,
}: {
  tasks: TaskListItem[];
  clients: TaskRelationOption[];
  projects: TaskRelationOption[];
}) {
  return (
    <div className="overflow-hidden rounded-sm border border-border">
      <div className="hidden grid-cols-[1.5fr_1fr_1fr_0.8fr_1fr] gap-4 border-b border-border bg-muted/40 px-4 py-3 text-xs font-medium uppercase text-muted-foreground lg:grid">
        <span>Görev</span>
        <span>Bağlantı</span>
        <span>Öncelik</span>
        <span>Son tarih</span>
        <span className="text-right">İşlem</span>
      </div>
      <div className="divide-y divide-border">
        {tasks.map((task) => (
          <TaskRow key={task.id} task={task} clients={clients} projects={projects} />
        ))}
      </div>
    </div>
  );
}

function TaskRow({
  task,
  clients,
  projects,
}: {
  task: TaskListItem;
  clients: TaskRelationOption[];
  projects: TaskRelationOption[];
}) {
  return (
    <div className="grid gap-4 px-4 py-4 lg:grid-cols-[1.5fr_1fr_1fr_0.8fr_1fr] lg:items-center">
      <div className="min-w-0">
        <div className={task.status === "done" ? "font-medium text-muted-foreground line-through" : "font-medium text-foreground"}>
          {task.title}
        </div>
        <div className="truncate text-sm text-muted-foreground">
          {statusLabels[task.status]}
        </div>
      </div>
      <div className="text-sm text-muted-foreground">
        <div>{task.projectName || "Proje yok"}</div>
        <div>{task.clientName || "Müşteri yok"}</div>
      </div>
      <div>
        <Badge className={priorityClasses[task.priority]}>
          {priorityLabels[task.priority]}
        </Badge>
      </div>
      <div className={isOverdue(task) ? "text-sm font-medium text-rose-600" : "text-sm text-muted-foreground"}>
        {task.due_at ? formatDateTime(task.due_at) : "Yok"}
      </div>
      <TaskActions task={task} clients={clients} projects={projects} />
    </div>
  );
}

function TaskKanban({
  tasks,
  clients,
  projects,
  onTaskStatusChange,
}: {
  tasks: TaskListItem[];
  clients: TaskRelationOption[];
  projects: TaskRelationOption[];
  onTaskStatusChange: (taskId: string, status: TaskListItem["status"]) => void;
}) {
  const columns = ["todo", "in_progress", "done"] as const;
  const [draggedTaskId, setDraggedTaskId] = useState<string | null>(null);

  function handleDragStart(event: DragEvent<HTMLDivElement>, taskId: string) {
    setDraggedTaskId(taskId);
    event.dataTransfer.effectAllowed = "move";
    event.dataTransfer.setData("text/plain", taskId);
    event.dataTransfer.setDragImage(event.currentTarget, 24, 24);
  }

  function handleDrop(status: TaskListItem["status"]) {
    if (!draggedTaskId) return;

    onTaskStatusChange(draggedTaskId, status);
    setDraggedTaskId(null);
  }

  return (
    <div className="tiny-scrollbar grid gap-4 overflow-x-auto pb-2 lg:grid-cols-3">
      {columns.map((status) => {
        const columnTasks = tasks.filter((task) => task.status === status);

        return (
          <div
            key={status}
            className="min-w-72 rounded-sm border border-border bg-muted/20 p-3 transition-colors"
            onDragOver={(event) => {
              event.preventDefault();
              event.dataTransfer.dropEffect = "move";
            }}
            onDrop={() => handleDrop(status)}
          >
            <div className="mb-3 flex items-center justify-between">
              <h3 className="text-sm font-semibold text-foreground">{statusLabels[status]}</h3>
              <Badge>{columnTasks.length}</Badge>
            </div>
            <div className="space-y-3">
              {columnTasks.map((task) => (
                <Card
                  key={task.id}
                  draggable
                  className={
                    draggedTaskId === task.id
                      ? "cursor-grabbing opacity-50 ring-2 ring-primary/20 transition"
                      : "cursor-grab transition hover:border-primary/30 active:cursor-grabbing"
                  }
                  onDragStart={(event) => handleDragStart(event, task.id)}
                  onDragEnd={() => setDraggedTaskId(null)}
                >
                  <CardContent className="space-y-3 p-3">
                    <div>
                      <div className="font-medium text-foreground">{task.title}</div>
                      <div className="text-sm text-muted-foreground">
                        {task.projectName || task.clientName || "Bağlantı yok"}
                      </div>
                    </div>
                    <div className="flex items-center justify-between gap-2">
                      <Badge className={priorityClasses[task.priority]}>
                        {priorityLabels[task.priority]}
                      </Badge>
                      <TaskActions task={task} clients={clients} projects={projects} compact />
                    </div>
                  </CardContent>
                </Card>
              ))}
            </div>
          </div>
        );
      })}
    </div>
  );
}

function TaskActions({
  task,
  clients,
  projects,
  compact = false,
}: {
  task: TaskListItem;
  clients: TaskRelationOption[];
  projects: TaskRelationOption[];
  compact?: boolean;
}) {
  return (
    <div className={compact ? "flex justify-end gap-1" : "flex justify-start gap-2 lg:justify-end"}>
      <TaskDialog mode="edit" task={task} clients={clients} projects={projects} />
      {task.status !== "done" ? (
        <form action={completeTaskRecord}>
          <input type="hidden" name="id" value={task.id} />
          <Button type="submit" variant="outline" className="h-9 min-w-24 gap-2 px-3">
            <CheckCircle2 className="h-4 w-4" />
            {!compact ? "Tamamla" : null}
          </Button>
        </form>
      ) : null}
      <form action={deleteTaskRecord}>
        <input type="hidden" name="id" value={task.id} />
        <Button type="submit" variant="outline" className="h-9 gap-2 px-3 text-rose-600">
          <Trash2 className="h-4 w-4" />
        </Button>
      </form>
    </div>
  );
}

function TaskDialog({
  mode,
  task,
  clients,
  projects,
}: {
  mode: "create" | "edit";
  task?: TaskListItem;
  clients: TaskRelationOption[];
  projects: TaskRelationOption[];
}) {
  const [open, setOpen] = useState(false);
  const [isSubmitting, setIsSubmitting] = useState(false);
  const action = mode === "create" ? createTaskRecord : updateTaskRecord;

  async function handleSubmit(formData: FormData) {
    setIsSubmitting(true);

    try {
      await action(formData);
      setOpen(false);
    } finally {
      setIsSubmitting(false);
    }
  }

  return (
    <Dialog open={open} onOpenChange={setOpen}>
      <DialogTrigger asChild>
        <Button
          variant={mode === "create" ? "default" : "outline"}
          className="h-9 min-w-24 gap-2 px-3"
        >
          {mode === "create" ? <Plus className="h-4 w-4" /> : <Pencil className="h-4 w-4" />}
          {mode === "create" ? "Görev ekle" : "Düzenle"}
        </Button>
      </DialogTrigger>
      <DialogContent className="max-h-[min(680px,calc(100dvh-6rem))] overflow-hidden sm:max-w-xl data-[state=open]:animate-in data-[state=open]:fade-in-0 data-[state=open]:zoom-in-95">
        <form action={handleSubmit} className="flex max-h-[min(640px,calc(100dvh-9rem))] flex-col">
          {task ? <input type="hidden" name="id" value={task.id} /> : null}
          <DialogHeader className="shrink-0 pb-5">
            <DialogTitle>{mode === "create" ? "Yeni görev" : "Görevi düzenle"}</DialogTitle>
            <DialogDescription>
              Görevi proje, müşteri, öncelik ve son tarih bilgileriyle kaydet.
            </DialogDescription>
          </DialogHeader>

          <div className="tiny-scrollbar min-h-0 flex-1 overflow-y-auto pr-2">
            <TaskFormFields task={task} clients={clients} projects={projects} />
          </div>

          <DialogFooter className="shrink-0 border-t border-border pt-5">
            <Button type="submit" disabled={isSubmitting} className="gap-2">
              {mode === "create" ? <Plus className="h-4 w-4" /> : <Pencil className="h-4 w-4" />}
              {isSubmitting
                ? "Kaydediliyor"
                : mode === "create"
                  ? "Görevi ekle"
                  : "Değişiklikleri kaydet"}
            </Button>
          </DialogFooter>
        </form>
      </DialogContent>
    </Dialog>
  );
}

function TaskFormFields({
  task,
  clients,
  projects,
}: {
  task?: TaskListItem;
  clients: TaskRelationOption[];
  projects: TaskRelationOption[];
}) {
  const [clientId, setClientId] = useState(task?.client_id || "__none");
  const [projectId, setProjectId] = useState(task?.project_id || "__none");
  const selectedProject =
    projectId === "__none" ? null : projects.find((project) => project.id === projectId) || null;
  const shouldLockClient = Boolean(selectedProject);
  const filteredProjects =
    clientId === "__none" || shouldLockClient
      ? projects
      : projects.filter((project) => project.client_id === clientId);

  function handleClientChange(nextClientId: string) {
    setClientId(nextClientId);

    if (
      projectId !== "__none" &&
      nextClientId !== "__none" &&
      !projects.some((project) => project.id === projectId && project.client_id === nextClientId)
    ) {
      setProjectId("__none");
    }
  }

  function handleProjectChange(nextProjectId: string) {
    setProjectId(nextProjectId);

    if (nextProjectId === "__none") {
      return;
    }

    const nextProject = projects.find((project) => project.id === nextProjectId);
    setClientId(nextProject?.client_id || "__none");
  }

  return (
    <div className="grid gap-4">
      <div className="grid gap-2">
        <Label htmlFor={`title-${task?.id || "new"}`}>Başlık</Label>
        <Input
          id={`title-${task?.id || "new"}`}
          name="title"
          defaultValue={task?.title || ""}
          required
          placeholder="Örn. Ana sayfa wireframe revizyonu"
        />
      </div>

      <div className="grid gap-2">
        <Label htmlFor={`description-${task?.id || "new"}`}>Açıklama</Label>
        <Textarea
          id={`description-${task?.id || "new"}`}
          name="description"
          defaultValue={task?.description || ""}
          rows={3}
          placeholder="Kapsam, not veya teslim kriterleri..."
        />
      </div>

      <div className="grid gap-4 md:grid-cols-2">
        <SelectField name="status" label="Durum" defaultValue={task?.status || "todo"}>
          <SelectItem value="todo">Yapılacak</SelectItem>
          <SelectItem value="in_progress">Devam ediyor</SelectItem>
          <SelectItem value="done">Tamamlandı</SelectItem>
        </SelectField>
        <SelectField name="priority" label="Öncelik" defaultValue={task?.priority || "medium"}>
          <SelectItem value="low">Düşük</SelectItem>
          <SelectItem value="medium">Orta</SelectItem>
          <SelectItem value="high">Yüksek</SelectItem>
          <SelectItem value="urgent">Acil</SelectItem>
        </SelectField>
      </div>

      <div className="grid gap-4 md:grid-cols-2">
        <div className="grid gap-2">
          <Label>Müşteri</Label>
          {shouldLockClient ? <input type="hidden" name="client_id" value={clientId} /> : null}
          <Select
            name="client_id"
            value={clientId}
            onValueChange={handleClientChange}
            disabled={shouldLockClient}
          >
            <SelectTrigger>
              <SelectValue placeholder="Müşteri seç" />
            </SelectTrigger>
            <SelectContent>
              <SelectItem value="__none">Müşteri yok</SelectItem>
              {clients.map((client) => (
                <SelectItem key={client.id} value={client.id}>
                  {client.name}
                </SelectItem>
              ))}
            </SelectContent>
          </Select>
        </div>
        <div className="grid gap-2">
          <Label>Proje</Label>
          <Select name="project_id" value={projectId} onValueChange={handleProjectChange}>
            <SelectTrigger>
              <SelectValue placeholder="Proje seç" />
            </SelectTrigger>
            <SelectContent>
              <SelectItem value="__none">Proje yok</SelectItem>
              {filteredProjects.map((project) => (
                <SelectItem key={project.id} value={project.id}>
                  {project.name}
                </SelectItem>
              ))}
            </SelectContent>
          </Select>
        </div>
      </div>

      <div className="grid gap-4 md:grid-cols-3">
        <div className="grid gap-2">
          <Label htmlFor={`due-${task?.id || "new"}`}>Son tarih</Label>
          <Input
            id={`due-${task?.id || "new"}`}
            name="due_at"
            type="datetime-local"
            defaultValue={task?.due_at ? toDateTimeLocal(task.due_at) : ""}
          />
        </div>
        <div className="grid gap-2">
          <Label htmlFor={`estimated-${task?.id || "new"}`}>Tahmini süre</Label>
          <Input
            id={`estimated-${task?.id || "new"}`}
            name="estimated_minutes"
            type="number"
            min="0"
            defaultValue={task?.estimated_minutes ?? ""}
            placeholder="Dakika"
          />
        </div>
        <div className="grid gap-2">
          <Label htmlFor={`actual-${task?.id || "new"}`}>Gerçekleşen süre</Label>
          <Input
            id={`actual-${task?.id || "new"}`}
            name="actual_minutes"
            type="number"
            min="0"
            defaultValue={task?.actual_minutes ?? ""}
            placeholder="Dakika"
          />
        </div>
      </div>
    </div>
  );
}

function SelectField({
  name,
  label,
  defaultValue,
  children,
}: {
  name: string;
  label: string;
  defaultValue: string;
  children: React.ReactNode;
}) {
  return (
    <div className="grid gap-2">
      <Label>{label}</Label>
      <Select name={name} defaultValue={defaultValue}>
        <SelectTrigger>
          <SelectValue placeholder={`${label} seç`} />
        </SelectTrigger>
        <SelectContent>{children}</SelectContent>
      </Select>
    </div>
  );
}

function StatCard({ label, value }: { label: string; value: string }) {
  return (
    <Card>
      <CardContent className="flex items-center justify-between gap-3 p-4">
        <div>
          <p className="text-sm text-muted-foreground">{label}</p>
          <p className="mt-1 text-2xl font-semibold text-foreground">{value}</p>
        </div>
        <div className="flex h-10 w-10 items-center justify-center rounded-sm bg-primary/10 text-primary">
          <CheckCircle2 className="h-5 w-5" />
        </div>
      </CardContent>
    </Card>
  );
}

function EmptyState({ hasQuery }: { hasQuery: boolean }) {
  return (
    <div className="flex min-h-72 flex-col items-center justify-center rounded-sm border border-dashed border-border bg-muted/20 p-8 text-center">
      <CheckCircle2 className="h-10 w-10 text-muted-foreground" />
      <h3 className="mt-4 text-lg font-semibold text-foreground">
        {hasQuery ? "Aramana uygun görev yok" : "Henüz görev eklenmedi"}
      </h3>
      <p className="mt-2 max-w-md text-sm text-muted-foreground">
        {hasQuery
          ? "Arama metnini sadeleştirerek tekrar deneyebilirsin."
          : "İlk görevini ekleyerek proje ve müşteri operasyonunu takip etmeye başlayabilirsin."}
      </p>
    </div>
  );
}

function isOverdue(task: TaskListItem) {
  return Boolean(task.due_at && task.status !== "done" && new Date(task.due_at) < new Date());
}

function formatDateTime(value: string) {
  return new Intl.DateTimeFormat("tr-TR", {
    day: "2-digit",
    month: "short",
    hour: "2-digit",
    minute: "2-digit",
  }).format(new Date(value));
}

function toDateTimeLocal(value: string) {
  const date = new Date(value);
  const offsetDate = new Date(date.getTime() - date.getTimezoneOffset() * 60_000);
  return offsetDate.toISOString().slice(0, 16);
}