"use client";

import { useActionState, useEffect, useRef, useState, useTransition } from "react";
import { useRouter } from "next/navigation";
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/components/ui/card";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/components/ui/table";
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from "@/components/ui/dialog";
import { Plus, Trash2 } from "lucide-react";
import { addUser, deleteUser, sendTestEmail, type ActionResult } from "@/actions/settings";
import { updateDefaultPrice } from "@/actions/pricing";
import { toast } from "sonner";
import type { AppUser, FuelSettings } from "@/lib/types";

const initial: ActionResult = { ok: false, error: "" };

interface Props {
  currentUserId: string;
  settings: FuelSettings | null;
  users: AppUser[];
}

export function SettingsForms({ currentUserId, settings, users }: Props) {
  const router = useRouter();
  const [defaultPrice, setDefaultPrice] = useState(settings?.default_price_per_litre || 0);

  function onSaveDefault() {
    startTransition(async () => {
      const res = await updateDefaultPrice(defaultPrice);
      if (res.ok) {
        toast.success("Default price saved");
        router.refresh();
      } else {
        toast.error(res.error);
      }
    });
  }

  const [, startTransition] = useTransition();
  const [testEmail, setTestEmail] = useState("");

  function onSendTest() {
    if (!testEmail) {
      toast.error("Enter a recipient email");
      return;
    }
    startTransition(async () => {
      const res = await sendTestEmail(testEmail);
      if (res.ok) toast.success("Test email sent");
      else toast.error(res.error);
    });
  }

  return (
    <div className="space-y-6">
      <div>
        <h1 className="text-2xl font-semibold tracking-tight">Settings</h1>
        <p className="text-sm text-muted-foreground">Fuel price, email, users, and price increase</p>
      </div>

      <div className="grid gap-6 lg:grid-cols-2">
        <Card>
          <CardHeader>
            <CardTitle>Default fuel price</CardTitle>
            <CardDescription>Used when no per-customer rule applies</CardDescription>
          </CardHeader>
          <CardContent>
            <div className="flex items-end gap-2">
              <div className="space-y-2 flex-1">
                <Label htmlFor="dp">Default price (R / L)</Label>
                <Input
                  id="dp"
                  type="number"
                  step="0.01"
                  min="0"
                  value={defaultPrice}
                  onChange={(e) => setDefaultPrice(Number(e.target.value))}
                />
              </div>
              <Button onClick={onSaveDefault}>Save</Button>
            </div>
          </CardContent>
        </Card>

        <Card>
          <CardHeader>
            <CardTitle>Fuel price increase</CardTitle>
            <CardDescription>Quickly apply a cents increase to all customers (use Pricing page for details)</CardDescription>
          </CardHeader>
          <CardContent>
            <Button variant="outline" asChild>
              <a href="/pricing">Go to Pricing →</a>
            </Button>
          </CardContent>
        </Card>
      </div>

      <Card>
        <CardHeader>
          <CardTitle>Email delivery</CardTitle>
          <CardDescription>Customer statements are sent through Gmail SMTP.</CardDescription>
        </CardHeader>
        <CardContent className="space-y-4">
          <div className="rounded-md border bg-muted/30 p-3 text-sm">
            <p className="font-medium">Configured sender</p>
            <p className="text-muted-foreground">rjbulk01@gmail.com</p>
            <p className="mt-2 text-muted-foreground">
              Gmail credentials are managed by the deployment environment and are not stored in PocketBase.
            </p>
          </div>
          <div className="flex items-end gap-2 pt-2 border-t">
            <div className="space-y-2 flex-1">
              <Label htmlFor="test">Send test email to:</Label>
              <Input id="test" type="email" value={testEmail} onChange={(e) => setTestEmail(e.target.value)} />
            </div>
            <Button type="button" variant="outline" onClick={onSendTest}>
              Send test
            </Button>
          </div>
        </CardContent>
      </Card>

      <UsersSection currentUserId={currentUserId} users={users} />
    </div>
  );
}

function UsersSection({ currentUserId, users }: { currentUserId: string; users: AppUser[] }) {
  const router = useRouter();
  const [open, setOpen] = useState(false);
  const [deletingId, setDeletingId] = useState<string | null>(null);
  const [, startTransition] = useTransition();

  function onDelete(id: string) {
    startTransition(async () => {
      const res = await deleteUser(id);
      if (res.ok) {
        toast.success("User deleted");
        setDeletingId(null);
        router.refresh();
      } else {
        toast.error(res.error);
      }
    });
  }

  return (
    <Card>
      <CardHeader className="flex flex-row items-center justify-between">
        <div>
          <CardTitle>Users</CardTitle>
          <CardDescription>{users.length} user{users.length !== 1 ? "s" : ""}</CardDescription>
        </div>
        <Button onClick={() => setOpen(true)} size="sm">
          <Plus className="h-4 w-4" /> Add user
        </Button>
      </CardHeader>
      <Table>
        <TableHeader>
          <TableRow>
            <TableHead>Name</TableHead>
            <TableHead>Email</TableHead>
            <TableHead>Verified</TableHead>
            <TableHead className="w-12"></TableHead>
          </TableRow>
        </TableHeader>
        <TableBody>
          {users.map((u) => (
            <TableRow key={u.id}>
              <TableCell className="font-medium">{u.name || "—"}</TableCell>
              <TableCell className="text-muted-foreground">{u.email}</TableCell>
              <TableCell>{u.verified ? "Yes" : "No"}</TableCell>
              <TableCell>
                {u.id !== currentUserId && (
                  <Button variant="ghost" size="icon" onClick={() => setDeletingId(u.id)}>
                    <Trash2 className="h-4 w-4" />
                  </Button>
                )}
              </TableCell>
            </TableRow>
          ))}
        </TableBody>
      </Table>
      <AddUserDialog open={open} onOpenChange={setOpen} />
      <Dialog open={!!deletingId} onOpenChange={(v) => !v && setDeletingId(null)}>
        <DialogContent>
          <DialogHeader>
            <DialogTitle>Delete this user?</DialogTitle>
            <DialogDescription>They will lose access immediately. This cannot be undone.</DialogDescription>
          </DialogHeader>
          <DialogFooter>
            <Button variant="ghost" onClick={() => setDeletingId(null)}>Cancel</Button>
            <Button variant="destructive" onClick={() => deletingId && onDelete(deletingId)}>Delete</Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>
    </Card>
  );
}

function AddUserDialog({ open, onOpenChange }: { open: boolean; onOpenChange: (v: boolean) => void }) {
  const router = useRouter();
  const ref = useRef<HTMLFormElement>(null);
  const [pending, startTransition] = useTransition();
  const [state, action] = useActionState(addUser, initial);

  useEffect(() => {
    if (state.ok) {
      toast.success("User created");
      onOpenChange(false);
      ref.current?.reset();
      router.refresh();
    } else if (state.error) {
      toast.error(state.error);
    }
  }, [state, router, onOpenChange]);

  return (
    <Dialog open={open} onOpenChange={onOpenChange}>
      <DialogContent>
        <DialogHeader>
          <DialogTitle>Add user</DialogTitle>
          <DialogDescription>Create a new login for someone on your team.</DialogDescription>
        </DialogHeader>
        <form ref={ref} action={action} className="space-y-3">
          <div className="space-y-2">
            <Label htmlFor="u-name">Name</Label>
            <Input id="u-name" name="name" required />
          </div>
          <div className="space-y-2">
            <Label htmlFor="u-username">Username</Label>
            <Input id="u-username" name="username" required minLength={3} />
          </div>
          <div className="space-y-2">
            <Label htmlFor="u-email">Email</Label>
            <Input id="u-email" name="email" type="email" required />
          </div>
          <div className="space-y-2">
            <Label htmlFor="u-pwd">Password</Label>
            <Input id="u-pwd" name="password" type="password" required minLength={8} />
          </div>
          <DialogFooter>
            <Button type="button" variant="ghost" onClick={() => onOpenChange(false)}>Cancel</Button>
            <Button type="submit" disabled={pending}>
              {pending ? "Creating…" : "Create user"}
            </Button>
          </DialogFooter>
        </form>
      </DialogContent>
    </Dialog>
  );
}