import { useState } from "react";
import { Plus, Pencil, Trash2, Download } from "lucide-react";
import {
  useListPolicies,
  useCreatePolicy,
  useUpdatePolicy,
  useDeletePolicy,
  useSeedTemplate,
  type PolicyPayload,
} from "@/api/policies";
import { PolicyForm } from "@/components/PolicyForm";
import { Button } from "@/components/ui/button";
import { Badge } from "@/components/ui/badge";
import { Skeleton } from "@/components/ui/skeleton";
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from "@/components/ui/table";
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select";
import type { RoutingRule } from "@/types/api";

const TEMPLATES = ["hr", "finance", "engineering", "catchall"];

export function PoliciesPage() {
  const [formOpen, setFormOpen] = useState(false);
  const [editingRule, setEditingRule] = useState<RoutingRule | undefined>();

  const { data: policies, isLoading } = useListPolicies();
  const createMutation = useCreatePolicy();
  const updateMutation = useUpdatePolicy();
  const deleteMutation = useDeletePolicy();
  const seedMutation = useSeedTemplate();

  const handleSubmit = async (payload: PolicyPayload) => {
    if (editingRule) {
      await updateMutation.mutateAsync({ id: editingRule.id, payload });
    } else {
      await createMutation.mutateAsync(payload);
    }
    setFormOpen(false);
    setEditingRule(undefined);
  };

  const handleEdit = (rule: RoutingRule) => {
    setEditingRule(rule);
    setFormOpen(true);
  };

  const handleDelete = async (id: string) => {
    if (confirm("Supprimer cette politique ?")) {
      await deleteMutation.mutateAsync(id);
    }
  };

  const handleOpenCreate = () => {
    setEditingRule(undefined);
    setFormOpen(true);
  };

  const isPending =
    createMutation.isPending || updateMutation.isPending;

  return (
    <div className="space-y-4">
      <div className="flex items-center justify-between">
        <div>
          <h2 className="text-xl font-bold">Politiques de routage</h2>
          <p className="text-sm text-muted-foreground">
            Gérez les règles de routage intelligentes par tenant
          </p>
        </div>
        <div className="flex gap-2">
          {/* Seed template */}
          <Select
            onValueChange={(template) => seedMutation.mutate(template)}
            value=""
          >
            <SelectTrigger className="w-44">
              <Download className="h-4 w-4 mr-2" />
              <SelectValue placeholder="Importer template" />
            </SelectTrigger>
            <SelectContent>
              {TEMPLATES.map((t) => (
                <SelectItem key={t} value={t} className="capitalize">
                  {t}
                </SelectItem>
              ))}
            </SelectContent>
          </Select>

          <Button onClick={handleOpenCreate}>
            <Plus className="h-4 w-4 mr-2" />
            Nouvelle politique
          </Button>
        </div>
      </div>

      {isLoading ? (
        <div className="space-y-2">
          {Array.from({ length: 4 }).map((_, i) => (
            <Skeleton key={i} className="h-14 w-full" />
          ))}
        </div>
      ) : !policies || policies.length === 0 ? (
        <div className="flex flex-col items-center justify-center h-64 text-center border rounded-lg">
          <p className="text-muted-foreground font-medium">Aucune politique configurée</p>
          <p className="text-sm text-muted-foreground mt-1">
            Créez votre première politique ou importez un template.
          </p>
          <Button onClick={handleOpenCreate} className="mt-4">
            <Plus className="h-4 w-4 mr-2" /> Créer une politique
          </Button>
        </div>
      ) : (
        <div className="rounded-lg border">
          <Table>
            <TableHeader>
              <TableRow>
                <TableHead>Nom</TableHead>
                <TableHead>Priorité</TableHead>
                <TableHead>Statut</TableHead>
                <TableHead>Conditions</TableHead>
                <TableHead>Action</TableHead>
                <TableHead className="text-right">Actions</TableHead>
              </TableRow>
            </TableHeader>
            <TableBody>
              {policies.map((rule) => (
                <TableRow key={rule.id}>
                  <TableCell>
                    <div>
                      <p className="font-medium text-sm">{rule.name}</p>
                      {rule.description && (
                        <p className="text-xs text-muted-foreground truncate max-w-xs">
                          {rule.description}
                        </p>
                      )}
                    </div>
                  </TableCell>
                  <TableCell>
                    <Badge variant="outline">{rule.priority}</Badge>
                  </TableCell>
                  <TableCell>
                    <Badge variant={rule.is_enabled ? "success" : "secondary"}>
                      {rule.is_enabled ? "Actif" : "Désactivé"}
                    </Badge>
                  </TableCell>
                  <TableCell>
                    <span className="text-sm text-muted-foreground">
                      {rule.conditions.length} condition{rule.conditions.length !== 1 ? "s" : ""}
                    </span>
                  </TableCell>
                  <TableCell>
                    <span className="text-sm font-mono">
                      {rule.action.provider}/{rule.action.model}
                    </span>
                  </TableCell>
                  <TableCell className="text-right">
                    <div className="flex justify-end gap-2">
                      <Button
                        variant="ghost"
                        size="icon"
                        onClick={() => handleEdit(rule)}
                        title="Modifier"
                      >
                        <Pencil className="h-4 w-4" />
                      </Button>
                      <Button
                        variant="ghost"
                        size="icon"
                        onClick={() => handleDelete(rule.id)}
                        title="Supprimer"
                        disabled={deleteMutation.isPending}
                      >
                        <Trash2 className="h-4 w-4 text-destructive" />
                      </Button>
                    </div>
                  </TableCell>
                </TableRow>
              ))}
            </TableBody>
          </Table>
        </div>
      )}

      <PolicyForm
        open={formOpen}
        onOpenChange={(open) => {
          setFormOpen(open);
          if (!open) setEditingRule(undefined);
        }}
        rule={editingRule}
        onSubmit={handleSubmit}
        isPending={isPending}
      />
    </div>
  );
}