import { createFileRoute } from "@tanstack/react-router";
import { useEffect, useState } from "react";
import { supabase } from "@/integrations/supabase/client";
import { useAuth } from "@/lib/auth";
import { Button } from "@/components/ui/button";
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import { Textarea } from "@/components/ui/textarea";
import { Switch } from "@/components/ui/switch";
import { Loader2, Mail, Send, KeyRound } from "lucide-react";
import { toast } from "sonner";

export const Route = createFileRoute("/settings/smtp")({
  component: SmtpSettingsPage,
});

const EMPTY = {
  host: "",
  port: "587",
  secure: false,
  username: "",
  from_email: "",
  from_name: "",
  reply_to: "",
  enabled: true,
  notes: "",
};

function SmtpSettingsPage() {
  const { user, isAdmin } = useAuth();
  const [loading, setLoading] = useState(true);
  const [saving, setSaving] = useState(false);
  const [testing, setTesting] = useState(false);
  const [recordId, setRecordId] = useState<string | null>(null);
  const [form, setForm] = useState({ ...EMPTY });
  const [testTo, setTestTo] = useState("");

  const load = async () => {
    setLoading(true);
    const { data } = await supabase
      .from("smtp_settings")
      .select("*")
      .order("updated_at", { ascending: false })
      .limit(1)
      .maybeSingle();
    if (data) {
      setRecordId(data.id);
      setForm({
        host: data.host ?? "",
        port: String(data.port ?? 587),
        secure: !!data.secure,
        username: data.username ?? "",
        from_email: data.from_email ?? "",
        from_name: data.from_name ?? "",
        reply_to: data.reply_to ?? "",
        enabled: data.enabled ?? true,
        notes: data.notes ?? "",
      });
    }
    setLoading(false);
  };

  useEffect(() => {
    if (isAdmin) load();
    else setLoading(false);
  }, [isAdmin]);

  const update = (k: keyof typeof EMPTY, v: string | boolean) =>
    setForm((f) => ({ ...f, [k]: v }));

  const save = async () => {
    if (!form.host || !form.from_email) {
      toast.error("Host and From email are required");
      return;
    }
    setSaving(true);
    const payload = {
      host: form.host.trim(),
      port: parseInt(form.port, 10) || 587,
      secure: form.secure,
      username: form.username || null,
      from_email: form.from_email.trim(),
      from_name: form.from_name || null,
      reply_to: form.reply_to || null,
      enabled: form.enabled,
      notes: form.notes || null,
      updated_by: user?.id,
    };
    const { error } = recordId
      ? await supabase.from("smtp_settings").update(payload).eq("id", recordId)
      : await supabase.from("smtp_settings").insert(payload);
    setSaving(false);
    if (error) {
      toast.error("Could not save", { description: error.message });
      return;
    }
    toast.success("SMTP settings saved");
    load();
  };

  const sendTest = async () => {
    if (!testTo) {
      toast.error("Enter a test recipient email");
      return;
    }
    setTesting(true);
    const { data, error } = await supabase.functions.invoke("send-smtp-email", {
      body: {
        to: testTo,
        subject: "SMTP test from your firm CRM",
        html: `<p>This is a test email sent from <strong>${form.from_email}</strong> via <code>${form.host}:${form.port}</code>.</p><p>If you received this, your SMTP settings are working.</p>`,
        text: `Test email from ${form.from_email} via ${form.host}:${form.port}.`,
      },
    });
    setTesting(false);
    if (error || (data as any)?.error) {
      toast.error("Send failed", {
        description: (error as any)?.message || (data as any)?.error,
      });
      return;
    }
    toast.success(`Test email sent to ${testTo}`);
  };

  if (!isAdmin) {
    return (
      <div className="text-sm text-muted-foreground py-8">
        Only administrators can manage SMTP settings.
      </div>
    );
  }
  if (loading) {
    return (
      <div className="flex justify-center py-16">
        <Loader2 className="h-5 w-5 animate-spin text-muted-foreground" />
      </div>
    );
  }

  return (
    <div className="space-y-6 max-w-3xl">
      <Card className="border-border/60">
        <CardHeader>
          <CardTitle className="font-serif text-base flex items-center gap-2">
            <Mail className="h-4 w-4 text-muted-foreground" /> SMTP server
          </CardTitle>
        </CardHeader>
        <CardContent className="grid gap-4 sm:grid-cols-2">
          <Field label="SMTP host *">
            <Input
              value={form.host}
              onChange={(e) => update("host", e.target.value)}
              placeholder="smtp.gmail.com"
            />
          </Field>
          <Field label="Port *">
            <Input
              type="number"
              value={form.port}
              onChange={(e) => update("port", e.target.value)}
              placeholder="587"
            />
          </Field>
          <Field label="Username">
            <Input
              value={form.username}
              onChange={(e) => update("username", e.target.value)}
              placeholder="user@yourdomain.com"
            />
          </Field>
          <div className="space-y-1.5">
            <Label className="text-xs">Password</Label>
            <div className="flex items-center gap-2 h-9 px-3 rounded-md border bg-muted/30 text-xs text-muted-foreground">
              <KeyRound className="h-3.5 w-3.5" />
              Stored securely as the <code>SMTP_PASSWORD</code> secret.
            </div>
          </div>
          <div className="sm:col-span-2 flex items-center justify-between rounded-md border p-3">
            <div>
              <div className="text-sm font-medium">Use TLS / SSL</div>
              <div className="text-xs text-muted-foreground">
                Enable for port 465 (implicit TLS). Leave off for 587 (STARTTLS).
              </div>
            </div>
            <Switch
              checked={form.secure}
              onCheckedChange={(v) => update("secure", v)}
            />
          </div>
        </CardContent>
      </Card>

      <Card className="border-border/60">
        <CardHeader>
          <CardTitle className="font-serif text-base">Sender identity</CardTitle>
        </CardHeader>
        <CardContent className="grid gap-4 sm:grid-cols-2">
          <Field label="From email *">
            <Input
              type="email"
              value={form.from_email}
              onChange={(e) => update("from_email", e.target.value)}
              placeholder="notifications@yourfirm.com"
            />
          </Field>
          <Field label="From name">
            <Input
              value={form.from_name}
              onChange={(e) => update("from_name", e.target.value)}
              placeholder="Your Firm"
            />
          </Field>
          <Field label="Reply-to (optional)" className="sm:col-span-2">
            <Input
              type="email"
              value={form.reply_to}
              onChange={(e) => update("reply_to", e.target.value)}
            />
          </Field>
          <Field label="Notes" className="sm:col-span-2">
            <Textarea
              rows={2}
              value={form.notes}
              onChange={(e) => update("notes", e.target.value)}
            />
          </Field>
          <div className="sm:col-span-2 flex items-center justify-between rounded-md border p-3">
            <div>
              <div className="text-sm font-medium">Enabled</div>
              <div className="text-xs text-muted-foreground">
                Disable to stop the system from sending email.
              </div>
            </div>
            <Switch
              checked={form.enabled}
              onCheckedChange={(v) => update("enabled", v)}
            />
          </div>
        </CardContent>
      </Card>

      <div className="flex justify-end">
        <Button onClick={save} disabled={saving}>
          {saving && <Loader2 className="h-4 w-4 mr-2 animate-spin" />}
          Save SMTP settings
        </Button>
      </div>

      <Card className="border-border/60">
        <CardHeader>
          <CardTitle className="font-serif text-base flex items-center gap-2">
            <Send className="h-4 w-4 text-muted-foreground" /> Send a test email
          </CardTitle>
        </CardHeader>
        <CardContent className="flex flex-col sm:flex-row gap-2">
          <Input
            type="email"
            placeholder="recipient@example.com"
            value={testTo}
            onChange={(e) => setTestTo(e.target.value)}
            className="flex-1"
          />
          <Button onClick={sendTest} disabled={testing || !recordId}>
            {testing ? (
              <Loader2 className="h-4 w-4 mr-2 animate-spin" />
            ) : (
              <Send className="h-4 w-4 mr-2" />
            )}
            Send test
          </Button>
        </CardContent>
      </Card>
    </div>
  );
}

function Field({
  label,
  className,
  children,
}: {
  label: string;
  className?: string;
  children: React.ReactNode;
}) {
  return (
    <div className={`space-y-1.5 ${className ?? ""}`}>
      <Label className="text-xs">{label}</Label>
      {children}
    </div>
  );
}