import { createFileRoute, Link, useNavigate } from "@tanstack/react-router";
import { useEffect, useMemo, useState } from "react";
import { ProtectedLayout } from "@/components/protected-layout";
import { PageContainer } from "@/components/app-shell";
import { supabase } from "@/integrations/supabase/client";
import { useAuth } from "@/lib/auth";
import { Button } from "@/components/ui/button";
import { Card, CardContent } from "@/components/ui/card";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import { Badge } from "@/components/ui/badge";
import { Checkbox } from "@/components/ui/checkbox";
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select";
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from "@/components/ui/dialog";
import { CollectionDetail } from "@/components/cases/collections-tab";
import { PaymentPlansPanel } from "@/components/collections/payment-plans-panel";
import { Tabs, TabsContent, TabsList, TabsTrigger } from "@/components/ui/tabs";
import { ContactsLinkTab } from "@/components/contacts/contacts-link-tab";
import { CaseCallLogsTab } from "@/components/cases/call-logs-tab";
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 { CaseCustomFieldsTab } from "@/components/cases/custom-fields-tab";
import { formatDate } from "@/lib/format";
import {
  ArrowLeft,
  ArrowRight,
  CheckCircle2,
  Circle,
  ListChecks,
  Loader2,
  Plus,
  Trash2,
  Workflow,
  Scale,
  Activity,
  FileText,
  Contact,
  Clock,
  DollarSign,
  Receipt,
  Phone,
  Tag,
} from "lucide-react";
import { toast } from "sonner";

export const Route = createFileRoute("/collections/$collectionId")({
  component: CollectionDetailRoute,
});

interface Stage {
  key: string;
  label: string;
  sort_order: number;
}

interface Profile {
  id: string;
  full_name: string;
  email: string;
}

interface Task {
  id: string;
  collection_id: string;
  stage_key: string | null;
  title: string;
  due_date: string | null;
  assignee_id: string | null;
  done: boolean;
  done_at: string | null;
  sort_order: number;
}

function CollectionDetailRoute() {
  const { collectionId } = Route.useParams();
  const navigate = useNavigate();
  const { user } = useAuth();

  const [collection, setCollection] = useState<any | null>(null);
  const [stages, setStages] = useState<Stage[]>([]);
  const [profiles, setProfiles] = useState<Profile[]>([]);
  const [tasks, setTasks] = useState<Task[]>([]);
  const [loading, setLoading] = useState(true);
  const [escalating, setEscalating] = useState(false);
  const [addTaskOpen, setAddTaskOpen] = useState(false);
  const [reload, setReload] = useState(0);

  useEffect(() => {
    let active = true;
    (async () => {
      setLoading(true);
      const [{ data: col }, { data: stgs }, { data: profs }] = await Promise.all([
        supabase
          .from("collections")
          .select(
            "*, homeowner:homeowners(*), case:cases(id, case_number, title, default_hourly_rate, client:clients(id, name, annual_interest_rate))",
          )
          .eq("id", collectionId)
          .maybeSingle(),
        supabase.from("collection_workflow_stages").select("*").order("sort_order"),
        supabase.from("profiles").select("id, full_name, email"),
      ]);
      if (!active) return;
      setCollection(col);
      setStages((stgs ?? []) as Stage[]);
      setProfiles((profs ?? []) as Profile[]);
      const { data: tsks } = await supabase
        .from("collection_tasks")
        .select("*")
        .eq("collection_id", collectionId)
        .order("done")
        .order("sort_order")
        .order("created_at");
      if (!active) return;
      setTasks((tsks ?? []) as Task[]);
      setLoading(false);
    })();
    return () => {
      active = false;
    };
  }, [collectionId, reload]);

  const refreshTasks = async () => {
    const { data } = await supabase
      .from("collection_tasks")
      .select("*")
      .eq("collection_id", collectionId)
      .order("done")
      .order("sort_order")
      .order("created_at");
    setTasks((data ?? []) as Task[]);
  };

  const currentStageIdx = useMemo(
    () => stages.findIndex((s) => s.key === collection?.current_stage),
    [stages, collection?.current_stage],
  );
  const nextStage = currentStageIdx >= 0 ? stages[currentStageIdx + 1] : null;
  const isLastStage = currentStageIdx === stages.length - 1;

  const escalate = async () => {
    if (!collection || !nextStage) return;
    if (
      !confirm(
        `Escalate to "${nextStage.label}"? This will populate the checklist tasks for that stage.`,
      )
    )
      return;
    setEscalating(true);

    // Update stage
    const { error: updErr } = await supabase
      .from("collections")
      .update({ current_stage: nextStage.key })
      .eq("id", collection.id);
    if (updErr) {
      setEscalating(false);
      toast.error("Could not escalate", { description: updErr.message });
      return;
    }

    // Pull templates for the new stage
    const { data: templates } = await supabase
      .from("collection_workflow_tasks")
      .select("*")
      .eq("stage_key", nextStage.key)
      .order("sort_order");

    if (templates && templates.length) {
      const today = new Date();
      const inserts = templates.map((t: any) => {
        const due = new Date(today);
        due.setDate(due.getDate() + (t.days_to_due ?? 7));
        return {
          collection_id: collection.id,
          stage_key: nextStage.key,
          title: t.title,
          due_date: due.toISOString().slice(0, 10),
          sort_order: t.sort_order,
          created_by: user?.id,
        };
      });
      const { error: insErr } = await supabase
        .from("collection_tasks")
        .insert(inserts);
      if (insErr) {
        toast.error("Stage advanced but task creation failed", {
          description: insErr.message,
        });
      }
    }

    setEscalating(false);
    toast.success(`Escalated to ${nextStage.label}`);
    setReload((r) => r + 1);
  };

  const toggleDone = async (t: Task) => {
    const next = !t.done;
    const { error } = await supabase
      .from("collection_tasks")
      .update({
        done: next,
        done_at: next ? new Date().toISOString() : null,
      })
      .eq("id", t.id);
    if (error) toast.error("Could not update", { description: error.message });
    else refreshTasks();
  };

  const deleteTask = async (id: string) => {
    if (!confirm("Delete this task?")) return;
    const { error } = await supabase
      .from("collection_tasks")
      .delete()
      .eq("id", id);
    if (error) toast.error("Could not delete", { description: error.message });
    else refreshTasks();
  };

  const updateAssignee = async (id: string, assignee_id: string | null) => {
    const { error } = await supabase
      .from("collection_tasks")
      .update({ assignee_id })
      .eq("id", id);
    if (error) toast.error("Could not update", { description: error.message });
    else refreshTasks();
  };

  const updateDueDate = async (id: string, due_date: string) => {
    const { error } = await supabase
      .from("collection_tasks")
      .update({ due_date: due_date || null })
      .eq("id", id);
    if (error) toast.error("Could not update", { description: error.message });
    else refreshTasks();
  };

  if (loading) {
    return (
      <ProtectedLayout>
        <PageContainer>
          <div className="p-12 text-center text-muted-foreground">Loading…</div>
        </PageContainer>
      </ProtectedLayout>
    );
  }

  if (!collection) {
    return (
      <ProtectedLayout>
        <PageContainer>
          <div className="p-12 text-center text-muted-foreground">
            Collection not found.{" "}
            <Link to="/collections" className="underline">
              Back
            </Link>
          </div>
        </PageContainer>
      </ProtectedLayout>
    );
  }

  const annualRate = collection.case?.client?.annual_interest_rate ?? null;
  const balanceFromOpening = Number(collection.homeowner?.opening_balance ?? 0);
  const currentStageLabel =
    stages.find((s) => s.key === collection.current_stage)?.label ?? "—";

  const openTasks = tasks.filter((t) => !t.done);
  const doneTasks = tasks.filter((t) => t.done);

  return (
    <ProtectedLayout>
      <PageContainer>
        <Button
          variant="ghost"
          size="sm"
          onClick={() => navigate({ to: "/collections" })}
          className="-ml-2 mb-3"
        >
          <ArrowLeft className="h-4 w-4 mr-1" /> All collections
        </Button>

        {/* Tabs: Workflow (collections-specific) + same case tabs */}
        <Tabs defaultValue="workflow">
          <TabsList className="mb-4 flex-wrap h-auto">
            <TabsTrigger value="workflow"><Workflow className="h-3.5 w-3.5 mr-1.5" />Workflow</TabsTrigger>
            {collection.case && (
              <>
                <TabsTrigger value="litigation"><Scale className="h-3.5 w-3.5 mr-1.5" />Litigation</TabsTrigger>
                <TabsTrigger value="status"><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>
                <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>
              </>
            )}
          </TabsList>

          <TabsContent value="workflow">
            {/* Workflow header */}
            <Card className="border-border/60 mb-4">
              <CardContent className="p-4 flex flex-wrap items-center justify-between gap-4">
                <div>
                  <div className="text-xs uppercase tracking-wider text-muted-foreground mb-1">
                    Workflow stage
                  </div>
                  <div className="flex items-center gap-2 flex-wrap">
                    {stages.map((s, i) => {
                      const isCurrent = s.key === collection.current_stage;
                      const isPast = i < currentStageIdx;
                      return (
                        <div key={s.key} className="flex items-center gap-2">
                          <Badge
                            variant={isCurrent ? "default" : "outline"}
                            className={
                              isCurrent
                                ? ""
                                : isPast
                                  ? "opacity-60 line-through"
                                  : "opacity-50"
                            }
                          >
                            {s.label}
                          </Badge>
                          {i < stages.length - 1 && (
                            <ArrowRight className="h-3 w-3 text-muted-foreground" />
                          )}
                        </div>
                      );
                    })}
                  </div>
                </div>
                <Button
                  onClick={escalate}
                  disabled={escalating || isLastStage || !nextStage}
                  size="lg"
                >
                  {escalating ? (
                    <Loader2 className="h-4 w-4 mr-2 animate-spin" />
                  ) : (
                    <ArrowRight className="h-4 w-4 mr-2" />
                  )}
                  {isLastStage
                    ? "Final stage"
                    : `Escalate → ${nextStage?.label ?? ""}`}
                </Button>
              </CardContent>
            </Card>

            {/* Tasks */}
            <Card className="border-border/60 mb-6">
              <CardContent className="p-4">
                <div className="flex items-center justify-between mb-3">
                  <h3 className="font-serif text-lg flex items-center gap-2">
                    <ListChecks className="h-4 w-4 text-muted-foreground" />
                    Tasks
                    {openTasks.length > 0 && (
                      <Badge variant="secondary" className="ml-1">
                        {openTasks.length} open
                      </Badge>
                    )}
                  </h3>
                  <Button size="sm" variant="outline" onClick={() => setAddTaskOpen(true)}>
                    <Plus className="h-3.5 w-3.5 mr-1" /> Add task
                  </Button>
                </div>
                {tasks.length === 0 ? (
                  <p className="text-sm text-muted-foreground italic py-4">
                    No tasks yet. Escalate to populate the next stage's checklist, or
                    add one manually.
                  </p>
                ) : (
                  <div className="space-y-1">
                    {[...openTasks, ...doneTasks].map((t) => {
                      const stageLabel =
                        stages.find((s) => s.key === t.stage_key)?.label;
                      const overdue =
                        !t.done &&
                        t.due_date &&
                        new Date(t.due_date) < new Date(new Date().toDateString());
                      return (
                        <div
                          key={t.id}
                          className={`flex items-center gap-3 px-2 py-2 rounded-md hover:bg-muted/40 ${
                            t.done ? "opacity-60" : ""
                          }`}
                        >
                          <button
                            onClick={() => toggleDone(t)}
                            className="shrink-0"
                            aria-label={t.done ? "Mark not done" : "Mark done"}
                          >
                            {t.done ? (
                              <CheckCircle2 className="h-5 w-5 text-emerald-600" />
                            ) : (
                              <Circle className="h-5 w-5 text-muted-foreground" />
                            )}
                          </button>
                          <div className="flex-1 min-w-0">
                            <div className={`text-sm ${t.done ? "line-through" : ""}`}>
                              {t.title}
                            </div>
                            {stageLabel && (
                              <div className="text-[10px] uppercase tracking-wider text-muted-foreground">
                                {stageLabel}
                              </div>
                            )}
                          </div>
                          <Input
                            type="date"
                            className={`h-8 w-[150px] text-xs ${
                              overdue ? "border-destructive text-destructive" : ""
                            }`}
                            value={t.due_date ?? ""}
                            onChange={(e) => updateDueDate(t.id, e.target.value)}
                          />
                          <Select
                            value={t.assignee_id ?? "unassigned"}
                            onValueChange={(v) =>
                              updateAssignee(t.id, v === "unassigned" ? null : v)
                            }
                          >
                            <SelectTrigger className="h-8 w-[180px] text-xs">
                              <SelectValue placeholder="Unassigned" />
                            </SelectTrigger>
                            <SelectContent>
                              <SelectItem value="unassigned">Unassigned</SelectItem>
                              {profiles.map((p) => (
                                <SelectItem key={p.id} value={p.id}>
                                  {p.full_name || p.email}
                                </SelectItem>
                              ))}
                            </SelectContent>
                          </Select>
                          <Button
                            variant="ghost"
                            size="icon"
                            className="h-8 w-8"
                            onClick={() => deleteTask(t.id)}
                          >
                            <Trash2 className="h-3.5 w-3.5 text-destructive" />
                          </Button>
                        </div>
                      );
                    })}
                  </div>
                )}
              </CardContent>
            </Card>

            {/* Payment plans */}
            <PaymentPlansPanel collectionId={collection.id} />

            {/* Ledger */}
            <CollectionDetail
              collection={collection}
              annualRate={annualRate}
              currentBalance={balanceFromOpening /* recalculated by detail */}
              onBack={() => navigate({ to: "/collections" })}
              onChange={() => setReload((r) => r + 1)}
            />
          </TabsContent>

          {collection.case && (
            <>
              <TabsContent value="litigation"><CaseLitigationTab caseRecord={collection.case} canManage={true} onSaved={() => setReload((r) => r + 1)} /></TabsContent>
              <TabsContent value="status"><CaseStatusTab caseId={collection.case.id} caseLabel={`${collection.case.case_number} — ${collection.case.title}`} /></TabsContent>
              <TabsContent value="documents"><CaseDocumentsTab caseId={collection.case.id} /></TabsContent>
              <TabsContent value="contacts"><ContactsLinkTab parentId={collection.case.id} parentTable="case_contacts" /></TabsContent>
              <TabsContent value="time"><CaseTimeTab caseRecord={collection.case} onInvoice={() => {}} /></TabsContent>
              <TabsContent value="expenses"><CaseExpensesTab caseId={collection.case.id} /></TabsContent>
              <TabsContent value="invoices"><CaseInvoicesTab caseRecord={collection.case} /></TabsContent>
              <TabsContent value="calls"><CaseCallLogsTab caseId={collection.case.id} /></TabsContent>
              <TabsContent value="custom"><CaseCustomFieldsTab caseId={collection.case.id} /></TabsContent>
            </>
          )}
        </Tabs>

        <AddTaskDialog
          open={addTaskOpen}
          onOpenChange={setAddTaskOpen}
          collectionId={collection.id}
          currentStageKey={collection.current_stage}
          profiles={profiles}
          userId={user?.id}
          onSaved={refreshTasks}
        />
      </PageContainer>
    </ProtectedLayout>
  );
}

function AddTaskDialog({
  open,
  onOpenChange,
  collectionId,
  currentStageKey,
  profiles,
  userId,
  onSaved,
}: {
  open: boolean;
  onOpenChange: (v: boolean) => void;
  collectionId: string;
  currentStageKey: string | null;
  profiles: Profile[];
  userId?: string;
  onSaved: () => void;
}) {
  const [title, setTitle] = useState("");
  const [dueDate, setDueDate] = useState(() => {
    const d = new Date();
    d.setDate(d.getDate() + 7);
    return d.toISOString().slice(0, 10);
  });
  const [assignee, setAssignee] = useState<string>("unassigned");
  const [submitting, setSubmitting] = useState(false);

  useEffect(() => {
    if (open) {
      setTitle("");
      const d = new Date();
      d.setDate(d.getDate() + 7);
      setDueDate(d.toISOString().slice(0, 10));
      setAssignee("unassigned");
    }
  }, [open]);

  const submit = async () => {
    if (!title.trim()) return toast.error("Title required");
    setSubmitting(true);
    const { error } = await supabase.from("collection_tasks").insert({
      collection_id: collectionId,
      stage_key: currentStageKey,
      title: title.trim(),
      due_date: dueDate || null,
      assignee_id: assignee === "unassigned" ? null : assignee,
      created_by: userId,
    });
    setSubmitting(false);
    if (error) {
      toast.error("Could not add", { description: error.message });
      return;
    }
    toast.success("Task added");
    onOpenChange(false);
    onSaved();
  };

  return (
    <Dialog open={open} onOpenChange={onOpenChange}>
      <DialogContent>
        <DialogHeader>
          <DialogTitle className="font-serif">Add task</DialogTitle>
          <DialogDescription>
            Manual task on this collection. Will be tagged with the current stage.
          </DialogDescription>
        </DialogHeader>
        <div className="space-y-3">
          <div>
            <Label>Title</Label>
            <Input
              value={title}
              onChange={(e) => setTitle(e.target.value)}
              placeholder="e.g. Call homeowner re: payment plan"
            />
          </div>
          <div className="grid grid-cols-2 gap-3">
            <div>
              <Label>Due date</Label>
              <Input
                type="date"
                value={dueDate}
                onChange={(e) => setDueDate(e.target.value)}
              />
            </div>
            <div>
              <Label>Assignee</Label>
              <Select value={assignee} onValueChange={setAssignee}>
                <SelectTrigger>
                  <SelectValue />
                </SelectTrigger>
                <SelectContent>
                  <SelectItem value="unassigned">Unassigned</SelectItem>
                  {profiles.map((p) => (
                    <SelectItem key={p.id} value={p.id}>
                      {p.full_name || p.email}
                    </SelectItem>
                  ))}
                </SelectContent>
              </Select>
            </div>
          </div>
        </div>
        <DialogFooter>
          <Button variant="outline" onClick={() => onOpenChange(false)}>
            Cancel
          </Button>
          <Button onClick={submit} disabled={submitting}>
            {submitting && <Loader2 className="h-4 w-4 mr-2 animate-spin" />}
            Add task
          </Button>
        </DialogFooter>
      </DialogContent>
    </Dialog>
  );
}