import { createFileRoute, Link } from "@tanstack/react-router";
import { useEffect, useState, useCallback, useMemo } from "react";
import { ProtectedLayout } from "@/components/protected-layout";
import { PageContainer, PageHeader } from "@/components/app-shell";
import { Button } from "@/components/ui/button";
import { Card, CardContent } from "@/components/ui/card";
import { Badge } from "@/components/ui/badge";
import { Tabs, TabsContent, TabsList, TabsTrigger } from "@/components/ui/tabs";
import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select";
import { Dialog, DialogContent, DialogDescription, DialogFooter, DialogHeader, DialogTitle } from "@/components/ui/dialog";
import { Input } from "@/components/ui/input";
import { supabase } from "@/integrations/supabase/client";
import { ArrowLeft, FileText, Clock, DollarSign, Activity, Receipt, Scale, Users, Contact, Phone, Tag, Archive, ArchiveRestore, ArrowRightLeft, Search, GitFork, Wallet } from "lucide-react";
import { TrustAccountPanel } from "@/components/trust/trust-account-panel";
import { ConvertToCollectionsDialog } from "@/components/cases/convert-to-collections-dialog";
import { ContactsLinkTab } from "@/components/contacts/contacts-link-tab";
import { CaseCallLogsTab } from "@/components/cases/call-logs-tab";
import { formatCurrency, formatDate, statusBadgeClass } from "@/lib/format";
import { CaseDocumentsTab } from "@/components/cases/documents-tab";
import { CaseTimeTab } from "@/components/cases/time-tab";
import { CaseExpensesTab } from "@/components/cases/expenses-tab";
import { CaseStatusTab } from "@/components/cases/status-tab";
import { CaseInvoicesTab } from "@/components/cases/invoices-tab";
import { CaseLitigationTab } from "@/components/cases/litigation-tab";
import { CaseCollectionsTab } from "@/components/cases/collections-tab";
import { CaseCustomFieldsTab } from "@/components/cases/custom-fields-tab";
import { setArchived } from "@/lib/archive";
import { toast } from "sonner";
import { useAuth } from "@/lib/auth";

export const Route = createFileRoute("/cases/$caseId")({
  component: () => (
    <ProtectedLayout>
      <CaseDetail />
    </ProtectedLayout>
  ),
});

function CaseDetail() {
  const { caseId } = Route.useParams();
  const { user, isAdmin } = useAuth();
  const [data, setData] = useState<any>(null);
  const [loading, setLoading] = useState(true);
  const [users, setUsers] = useState<any[]>([]);
  const [clients, setClients] = useState<any[]>([]);
  const [reassignOpen, setReassignOpen] = useState(false);
  const [convertOpen, setConvertOpen] = useState(false);
  const [activeTab, setActiveTab] = useState("litigation");
  const [clientSearch, setClientSearch] = useState("");
  const [selectedClientId, setSelectedClientId] = useState<string>("");
  const [reassigning, setReassigning] = useState(false);

  const load = useCallback(async () => {
    const [{ data: c, error }, { data: us }, { data: cl }] = await Promise.all([
      supabase
        .from("cases")
        .select("*, client:clients(id, name, client_type, annual_interest_rate), assignee:profiles!cases_assigned_attorney_id_fkey(id, full_name, email)")
        .eq("id", caseId)
        .maybeSingle(),
      supabase.from("profiles").select("id, full_name, email"),
      supabase.from("clients").select("id, name, client_type").is("archived_at", null).order("name"),
    ]);
    if (error) toast.error("Failed to load case", { description: error.message });
    setData(c);
    setUsers(us ?? []);
    setClients(cl ?? []);
    setLoading(false);
  }, [caseId]);

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

  const updateStatus = async (status: string) => {
    const { error } = await supabase
      .from("cases")
      .update({ status: status as "active" | "closed" | "closed_lost" | "closed_won" | "intake" | "on_hold", closed_at: status.startsWith("closed") ? new Date().toISOString().slice(0, 10) : null })
      .eq("id", caseId);
    if (error) toast.error("Could not update", { description: error.message });
    else {
      toast.success("Status updated");
      load();
    }
  };

  const updateAssignee = async (assigned_attorney_id: string) => {
    const { error } = await supabase.from("cases").update({ assigned_attorney_id }).eq("id", caseId);
    if (error) toast.error(error.message);
    else { toast.success("Assignee updated"); load(); }
  };

  const filteredClients = useMemo(() => {
    const q = clientSearch.trim().toLowerCase();
    if (!q) return clients.slice(0, 50);
    return clients.filter((c) => c.name.toLowerCase().includes(q)).slice(0, 50);
  }, [clients, clientSearch]);

  const reassignClient = async () => {
    if (!selectedClientId || selectedClientId === data.client?.id) {
      setReassignOpen(false);
      return;
    }
    setReassigning(true);
    const { error } = await supabase.from("cases").update({ client_id: selectedClientId }).eq("id", caseId);
    setReassigning(false);
    if (error) toast.error("Could not reassign", { description: error.message });
    else {
      toast.success("Case reassigned to new client");
      setReassignOpen(false);
      setClientSearch("");
      setSelectedClientId("");
      load();
    }
  };

  if (loading) return <PageContainer><p className="text-muted-foreground">Loading…</p></PageContainer>;
  if (!data) {
    return (
      <PageContainer>
        <p className="text-muted-foreground">Case not found or you don't have access.</p>
        <Button variant="outline" className="mt-3" asChild>
          <Link to="/cases"><ArrowLeft className="h-4 w-4 mr-2" /> All cases</Link>
        </Button>
      </PageContainer>
    );
  }

  const canManage = isAdmin || data.assigned_attorney_id === user?.id || data.created_by === user?.id;

  return (
    <PageContainer>
      <Button variant="ghost" size="sm" asChild className="mb-3 -ml-2">
        <Link to="/cases"><ArrowLeft className="h-4 w-4 mr-1" /> All cases</Link>
      </Button>

      <div className="flex flex-col lg:flex-row lg:items-end lg:justify-between gap-4 mb-6">
        <div>
          <div className="flex items-center gap-3 mb-1">
            <span className="text-xs uppercase tracking-widest text-muted-foreground">{data.case_number}</span>
            <Badge variant="outline" className={statusBadgeClass(data.status)}>{data.status.replace("_", " ")}</Badge>
            {data.archived_at && (
              <Badge variant="outline" className="bg-muted text-muted-foreground">
                <Archive className="h-3 w-3 mr-1" /> Archived
              </Badge>
            )}
          </div>
          <h1 className="font-serif text-3xl">{data.title}</h1>
          <p className="text-sm text-muted-foreground mt-1">
            <Link to="/clients/$clientId" params={{ clientId: data.client.id }} className="hover:text-primary underline-offset-4 hover:underline">
              {data.client.name}
            </Link>
            {" · "}{data.practice_area || "—"}{" · "}opened {formatDate(data.opened_at)}
          </p>
        </div>
        {canManage && (
          <div className="flex flex-wrap gap-2">
            <Select value={data.assigned_attorney_id ?? ""} onValueChange={updateAssignee}>
              <SelectTrigger className="w-[200px]"><SelectValue placeholder="Assign attorney" /></SelectTrigger>
              <SelectContent>
                {users.map((u) => <SelectItem key={u.id} value={u.id}>{u.full_name || u.email}</SelectItem>)}
              </SelectContent>
            </Select>
            <Select value={data.status} onValueChange={updateStatus}>
              <SelectTrigger className="w-[160px]"><SelectValue /></SelectTrigger>
              <SelectContent>
                <SelectItem value="intake">Intake</SelectItem>
                <SelectItem value="active">Active</SelectItem>
                <SelectItem value="on_hold">On hold</SelectItem>
                <SelectItem value="closed_won">Closed — won</SelectItem>
                <SelectItem value="closed_lost">Closed — lost</SelectItem>
                <SelectItem value="closed">Closed</SelectItem>
              </SelectContent>
            </Select>
            <Button
              variant="outline"
              onClick={() => {
                setSelectedClientId(data.client?.id ?? "");
                setReassignOpen(true);
              }}
            >
              <ArrowRightLeft className="h-4 w-4 mr-2" /> Reassign client
            </Button>
            {(data.client?.client_type === "hoa" || data.client?.client_type === "condo") && (
              <Button variant="outline" onClick={() => setConvertOpen(true)}>
                <GitFork className="h-4 w-4 mr-2" /> Convert to collections
              </Button>
            )}
            <Button
              variant="outline"
              onClick={async () => {
                if (await setArchived("cases", caseId, !data.archived_at)) load();
              }}
            >
              {data.archived_at ? (
                <><ArchiveRestore className="h-4 w-4 mr-2" /> Restore</>
              ) : (
                <><Archive className="h-4 w-4 mr-2" /> Archive</>
              )}
            </Button>
          </div>
        )}
      </div>

      <Dialog open={reassignOpen} onOpenChange={setReassignOpen}>
        <DialogContent className="max-w-lg">
          <DialogHeader>
            <DialogTitle>Reassign case to a different client</DialogTitle>
            <DialogDescription>
              Currently assigned to <span className="font-medium">{data.client?.name ?? "—"}</span>. Pick a new client below.
            </DialogDescription>
          </DialogHeader>
          <div className="space-y-3">
            <div className="relative">
              <Search className="absolute left-2.5 top-2.5 h-4 w-4 text-muted-foreground" />
              <Input
                placeholder="Search clients…"
                value={clientSearch}
                onChange={(e) => setClientSearch(e.target.value)}
                className="pl-8"
                autoFocus
              />
            </div>
            <div className="max-h-72 overflow-y-auto border rounded-md divide-y">
              {filteredClients.length === 0 ? (
                <p className="text-sm text-muted-foreground p-3">No clients match.</p>
              ) : (
                filteredClients.map((c) => (
                  <button
                    key={c.id}
                    type="button"
                    onClick={() => setSelectedClientId(c.id)}
                    className={`w-full text-left px-3 py-2 text-sm hover:bg-muted flex items-center justify-between ${
                      selectedClientId === c.id ? "bg-muted" : ""
                    }`}
                  >
                    <span>{c.name}</span>
                    <span className="text-xs text-muted-foreground uppercase">{c.client_type}</span>
                  </button>
                ))
              )}
            </div>
          </div>
          <DialogFooter>
            <Button variant="outline" onClick={() => setReassignOpen(false)}>Cancel</Button>
            <Button
              onClick={reassignClient}
              disabled={reassigning || !selectedClientId || selectedClientId === data.client?.id}
            >
              {reassigning ? "Reassigning…" : "Reassign"}
            </Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>

      {data.description && (
        <Card className="mb-6 border-border/60">
          <CardContent className="p-4">
            <p className="text-sm whitespace-pre-wrap">{data.description}</p>
          </CardContent>
        </Card>
      )}

      <CaseTabs data={data} caseId={caseId} canManage={canManage} load={load} tab={activeTab} onTabChange={setActiveTab} />

      <ConvertToCollectionsDialog
        open={convertOpen}
        onOpenChange={setConvertOpen}
        caseId={caseId}
        clientId={data.client?.id ?? ""}
        caseTitle={data.title || ""}
        onCreated={() => {
          setActiveTab("collections");
          load();
        }}
      />

      <div className="mt-8 grid grid-cols-2 sm:grid-cols-4 gap-3 text-center text-xs">
        <SmallStat label="Default rate" value={data.default_hourly_rate ? formatCurrency(data.default_hourly_rate) + "/hr" : "—"} />
        <SmallStat label="Attorney" value={data.assignee?.full_name || data.assignee?.email || "—"} />
        <SmallStat label="Closed" value={data.closed_at ? formatDate(data.closed_at) : "—"} />
        <SmallStat label="Updated" value={formatDate(data.updated_at)} />
      </div>
    </PageContainer>
  );
}

function CaseTabs({ data, caseId, canManage, load, tab, onTabChange }: { data: any; caseId: string; canManage: boolean; load: () => void; tab: string; onTabChange: (v: string) => void }) {
  return (
    <Tabs value={tab} onValueChange={onTabChange}>
      <TabsList className="mb-4 flex-wrap h-auto">
        <TabsTrigger value="litigation"><Scale className="h-3.5 w-3.5 mr-1.5" />Litigation</TabsTrigger>
        <TabsTrigger value="overview"><Activity className="h-3.5 w-3.5 mr-1.5" />Status log</TabsTrigger>
        <TabsTrigger value="documents"><FileText className="h-3.5 w-3.5 mr-1.5" />Documents</TabsTrigger>
        <TabsTrigger value="contacts"><Contact className="h-3.5 w-3.5 mr-1.5" />Contacts</TabsTrigger>
        <TabsTrigger value="time"><Clock className="h-3.5 w-3.5 mr-1.5" />Time</TabsTrigger>
        <TabsTrigger value="expenses"><DollarSign className="h-3.5 w-3.5 mr-1.5" />Expenses</TabsTrigger>
        <TabsTrigger value="invoices"><Receipt className="h-3.5 w-3.5 mr-1.5" />Invoices</TabsTrigger>
        {data.client_id && (
          <TabsTrigger value="trust"><Wallet className="h-3.5 w-3.5 mr-1.5" />Trust</TabsTrigger>
        )}
        <TabsTrigger value="calls"><Phone className="h-3.5 w-3.5 mr-1.5" />Calls</TabsTrigger>
        <TabsTrigger value="custom"><Tag className="h-3.5 w-3.5 mr-1.5" />Custom fields</TabsTrigger>
        {(data.client?.client_type === "hoa" || data.client?.client_type === "condo") && (
          <TabsTrigger value="collections"><Users className="h-3.5 w-3.5 mr-1.5" />Collections</TabsTrigger>
        )}
      </TabsList>
      <TabsContent value="litigation"><CaseLitigationTab caseRecord={data} canManage={canManage} onSaved={load} /></TabsContent>
      <TabsContent value="overview"><CaseStatusTab caseId={caseId} caseLabel={`${data.case_number} — ${data.title}`} /></TabsContent>
      <TabsContent value="documents"><CaseDocumentsTab caseId={caseId} /></TabsContent>
      <TabsContent value="contacts"><ContactsLinkTab parentId={caseId} parentTable="case_contacts" /></TabsContent>
      <TabsContent value="time"><CaseTimeTab caseRecord={data} onInvoice={() => onTabChange("invoices")} /></TabsContent>
      <TabsContent value="expenses"><CaseExpensesTab caseId={caseId} /></TabsContent>
      <TabsContent value="invoices"><CaseInvoicesTab caseRecord={data} /></TabsContent>
      {data.client_id && (
        <TabsContent value="trust"><TrustAccountPanel clientId={data.client_id} caseId={caseId} /></TabsContent>
      )}
      <TabsContent value="calls"><CaseCallLogsTab caseId={caseId} /></TabsContent>
      <TabsContent value="custom"><CaseCustomFieldsTab caseId={caseId} /></TabsContent>
      {(data.client?.client_type === "hoa" || data.client?.client_type === "condo") && (
        <TabsContent value="collections"><CaseCollectionsTab caseRecord={data} /></TabsContent>
      )}
    </Tabs>
  );
}

function SmallStat({ label, value }: { label: string; value: string }) {
  return (
    <div className="border rounded-md py-2 px-3">
      <div className="text-[10px] uppercase tracking-wider text-muted-foreground">{label}</div>
      <div className="text-sm font-medium mt-0.5 truncate">{value}</div>
    </div>
  );
}