import { createFileRoute, Link } from "@tanstack/react-router";
import { useEffect, useMemo, useState } from "react";
import { ProtectedLayout } from "@/components/protected-layout";
import { PageContainer, PageHeader } from "@/components/app-shell";
import { supabase } from "@/integrations/supabase/client";
import { Card, CardContent } from "@/components/ui/card";
import { Badge } from "@/components/ui/badge";
import { Input } from "@/components/ui/input";
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select";
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from "@/components/ui/table";
import { formatCurrency, formatDate } from "@/lib/format";
import { ChevronRight, CalendarClock, Search, ArrowUp, ArrowDown, ArrowUpDown } from "lucide-react";

export const Route = createFileRoute("/payment-plans/")({
  component: PaymentPlansIndexPage,
});

function PaymentPlansIndexPage() {
  const [rows, setRows] = useState<any[]>([]);
  const [installments, setInstallments] = useState<Record<string, any[]>>({});
  const [loading, setLoading] = useState(true);
  const [search, setSearch] = useState("");
  const [statusFilter, setStatusFilter] = useState<string>("active");
  const [freqFilter, setFreqFilter] = useState<string>("all");
  const [sortKey, setSortKey] = useState<
    "name" | "case" | "frequency" | "next" | "progress" | "total" | "remaining" | "started"
  >("started");
  const [sortDir, setSortDir] = useState<"asc" | "desc">("desc");

  const toggleSort = (key: typeof sortKey) => {
    if (sortKey === key) setSortDir((d) => (d === "asc" ? "desc" : "asc"));
    else { setSortKey(key); setSortDir("asc"); }
  };

  const load = async () => {
    setLoading(true);
    const { data: plans } = await supabase
      .from("payment_plans")
      .select(
        "id, name, status, total_amount, down_payment, installment_count, installment_amount, frequency, start_date, created_at, case_id, collection_id, case:cases(id, case_number, title, client:clients(id, name)), collection:collections(id, case_id, homeowner:homeowners(id, first_name, last_name, unit_number), case:cases(id, case_number, title, client:clients(id, name)))",
      )
      .order("created_at", { ascending: false });
    const list = plans ?? [];
    setRows(list);

    if (list.length) {
      const ids = list.map((p: any) => p.id);
      const { data: inst } = await supabase
        .from("payment_plan_installments")
        .select("plan_id, amount, paid, paid_amount, due_date")
        .in("plan_id", ids)
        .order("due_date", { ascending: true });
      const map: Record<string, any[]> = {};
      (inst ?? []).forEach((i: any) => {
        (map[i.plan_id] ||= []).push(i);
      });
      setInstallments(map);
    }
    setLoading(false);
  };

  useEffect(() => {
    load();
  }, []);

  const computed = useMemo(() => {
    return rows.map((p: any) => {
      const ins = installments[p.id] ?? [];
      const total = Number(p.total_amount) || 0;
      const paidAmt = ins.reduce((s, i) => s + (i.paid ? Number(i.paid_amount ?? i.amount) || 0 : 0), 0);
      const remaining = total - paidAmt;
      const paidCount = ins.filter((i) => i.paid).length;
      const next = ins.find((i) => !i.paid);
      const homeowner = p.collection?.homeowner;
      const client =
        p.collection?.case?.client?.name ?? p.case?.client?.name ?? null;
      const caseRow = p.collection?.case ?? p.case ?? null;
      const displayName =
        p.name ||
        (homeowner ? `${homeowner.last_name}, ${homeowner.first_name}` : null) ||
        (caseRow ? `${caseRow.case_number} · ${caseRow.title}` : "Plan");
      const linkTo: { to: any; params: any } = p.collection_id
        ? { to: "/collections/$collectionId", params: { collectionId: p.collection_id } }
        : { to: "/cases/$caseId", params: { caseId: p.case_id } };
      return { plan: p, ins, total, paidAmt, remaining, paidCount, next, homeowner, client, caseRow, displayName, linkTo };
    });
  }, [rows, installments]);

  const filtered = computed.filter((r) => {
    if (statusFilter !== "all" && r.plan.status !== statusFilter) return false;
    if (freqFilter !== "all" && r.plan.frequency !== freqFilter) return false;
    if (!search.trim()) return true;
    const q = search.toLowerCase();
    return (
      (r.displayName ?? "").toLowerCase().includes(q) ||
      (r.client ?? "").toLowerCase().includes(q) ||
      (r.caseRow?.case_number ?? "").toLowerCase().includes(q) ||
      (r.caseRow?.title ?? "").toLowerCase().includes(q)
    );
  });

  const sorted = useMemo(() => {
    const getVal = (r: typeof filtered[number]): string | number => {
      switch (sortKey) {
        case "name":
          return (r.displayName ?? "").toLowerCase();
        case "case":
          return (r.client ?? "").toLowerCase();
        case "frequency":
          return r.plan.frequency ?? "";
        case "next":
          return r.next?.due_date ? new Date(r.next.due_date).getTime() : Infinity;
        case "progress":
          return r.plan.installment_count ? r.paidCount / r.plan.installment_count : 0;
        case "total":
          return r.total;
        case "remaining":
          return r.remaining;
        case "started":
          return r.plan.start_date ? new Date(r.plan.start_date).getTime() : 0;
      }
    };
    return [...filtered].sort((a, b) => {
      const av = getVal(a);
      const bv = getVal(b);
      if (av < bv) return sortDir === "asc" ? -1 : 1;
      if (av > bv) return sortDir === "asc" ? 1 : -1;
      return 0;
    });
  }, [filtered, sortKey, sortDir]);

  const SortHeader = ({ k, label, className }: { k: typeof sortKey; label: string; className?: string }) => {
    const Icon = sortKey !== k ? ArrowUpDown : sortDir === "asc" ? ArrowUp : ArrowDown;
    return (
      <TableHead className={className}>
        <button
          onClick={() => toggleSort(k)}
          className="inline-flex items-center gap-1 hover:text-foreground"
        >
          {label}
          <Icon className={`h-3 w-3 ${sortKey === k ? "" : "opacity-50"}`} />
        </button>
      </TableHead>
    );
  };

  return (
    <ProtectedLayout>
      <PageContainer>
        <PageHeader
          title="Payment plans"
          description="All installment plans across every matter."
        />
        <div className="flex gap-3 mb-4 flex-wrap">
          <div className="relative flex-1 min-w-[260px] max-w-md">
            <Search className="h-4 w-4 absolute left-3 top-1/2 -translate-y-1/2 text-muted-foreground" />
            <Input
              placeholder="Search plan, homeowner, HOA, case…"
              value={search}
              onChange={(e) => setSearch(e.target.value)}
              className="pl-9"
            />
          </div>
          <Select value={statusFilter} onValueChange={setStatusFilter}>
            <SelectTrigger className="w-[160px]">
              <SelectValue />
            </SelectTrigger>
            <SelectContent>
              <SelectItem value="active">Active</SelectItem>
              <SelectItem value="completed">Completed</SelectItem>
              <SelectItem value="cancelled">Cancelled</SelectItem>
              <SelectItem value="all">All statuses</SelectItem>
            </SelectContent>
          </Select>
          <Select value={freqFilter} onValueChange={setFreqFilter}>
            <SelectTrigger className="w-[180px]">
              <SelectValue />
            </SelectTrigger>
            <SelectContent>
              <SelectItem value="all">All frequencies</SelectItem>
              <SelectItem value="weekly">Weekly</SelectItem>
              <SelectItem value="biweekly">Biweekly</SelectItem>
              <SelectItem value="monthly">Monthly</SelectItem>
            </SelectContent>
          </Select>
        </div>

        <Card className="border-border/60">
          <CardContent className="p-0">
            {loading ? (
              <div className="p-12 text-center text-muted-foreground text-sm">
                Loading…
              </div>
            ) : sorted.length === 0 ? (
              <div className="p-16 text-center text-muted-foreground text-sm">
                <CalendarClock className="h-8 w-8 mx-auto mb-3 opacity-40" />
                No payment plans found.
              </div>
            ) : (
              <Table>
                <TableHeader>
                  <TableRow>
                    <SortHeader k="name" label="Plan / Homeowner" />
                    <SortHeader k="case" label="HOA / Case" />
                    <SortHeader k="frequency" label="Frequency" />
                    <SortHeader k="progress" label="Progress" className="text-center" />
                    <SortHeader k="next" label="Next due" />
                    <SortHeader k="total" label="Total" className="text-right" />
                    <SortHeader k="remaining" label="Remaining" className="text-right" />
                    <TableHead></TableHead>
                  </TableRow>
                </TableHeader>
                <TableBody>
                  {sorted.map((r) => (
                    <TableRow key={r.plan.id} className="cursor-pointer">
                      <TableCell className="font-medium">
                        <Link
                          {...r.linkTo}
                          className="hover:underline"
                        >
                          {r.displayName}
                          {r.homeowner?.unit_number && (
                            <span className="text-muted-foreground font-normal ml-1">
                              · Unit {r.homeowner.unit_number}
                            </span>
                          )}
                        </Link>
                        {r.plan.status !== "active" && (
                          <Badge variant="outline" className="ml-2 text-[10px] capitalize">
                            {r.plan.status}
                          </Badge>
                        )}
                      </TableCell>
                      <TableCell className="text-sm">
                        <div>{r.client ?? "—"}</div>
                        {r.caseRow && (
                          <div className="text-xs text-muted-foreground">
                            {r.caseRow.case_number} · {r.caseRow.title}
                          </div>
                        )}
                      </TableCell>
                      <TableCell>
                        <Badge variant="outline" className="text-[10px] capitalize">
                          {r.plan.frequency}
                        </Badge>
                      </TableCell>
                      <TableCell className="text-center text-sm">
                        {r.paidCount} / {r.plan.installment_count}
                      </TableCell>
                      <TableCell className="text-muted-foreground text-sm">
                        {r.next ? formatDate(r.next.due_date) : "—"}
                      </TableCell>
                      <TableCell className="text-right font-mono">
                        {formatCurrency(r.total)}
                      </TableCell>
                      <TableCell
                        className={`text-right font-mono ${
                          r.remaining > 0 ? "text-destructive font-semibold" : "text-emerald-600"
                        }`}
                      >
                        {formatCurrency(Math.max(0, r.remaining))}
                      </TableCell>
                      <TableCell className="text-right">
                        <Link {...r.linkTo}>
                          <ChevronRight className="h-4 w-4 text-muted-foreground inline" />
                        </Link>
                      </TableCell>
                    </TableRow>
                  ))}
                </TableBody>
              </Table>
            )}
          </CardContent>
        </Card>
      </PageContainer>
    </ProtectedLayout>
  );
}