import { createFileRoute, Link, useNavigate } 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 { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select";
import { Badge } from "@/components/ui/badge";
import { RichTextEditor } from "@/components/documents/rich-text-editor";
import {
  Loader2, ArrowLeft, Plus, Trash2, ChevronUp, ChevronDown, Save, ExternalLink, Image as ImageIcon, X,
} from "lucide-react";
import { toast } from "sonner";

export const Route = createFileRoute("/settings/public-pages/$pageId")({
  component: PublicPageEditor,
});

type PageRow = {
  id: string; slug: string; title: string; meta_description: string | null;
  status: string; show_in_nav: boolean; sort_order: number;
};

type SectionRow = {
  id: string; page_id: string; section_type: string; sort_order: number; content: any;
};

const SECTION_TYPES = [
  { value: "hero", label: "Hero (heading + subtext)" },
  { value: "rich_text", label: "Rich text block" },
  { value: "feature_grid", label: "Feature grid" },
  { value: "cta", label: "Call-to-action" },
  { value: "contact", label: "Contact info" },
  { value: "faq", label: "FAQ list" },
];

function defaultContent(type: string): any {
  switch (type) {
    case "hero": return { heading: "Heading", subheading: "Subheading", eyebrow: "" };
    case "rich_text": return { html: "<p>Write something...</p>" };
    case "feature_grid": return { heading: "Features", items: [{ title: "Feature 1", body: "Description" }] };
    case "cta": return { heading: "Ready to start?", subheading: "", button_label: "Contact us", button_url: "/p/contact" };
    case "contact": return { heading: "Get in touch", phone: "", email: "", address: "" };
    case "faq": return { heading: "FAQ", items: [{ q: "Question?", a: "Answer." }] };
    default: return {};
  }
}

function PublicPageEditor() {
  const { pageId } = Route.useParams();
  const { isAdmin } = useAuth();
  const navigate = useNavigate();
  const [loading, setLoading] = useState(true);
  const [saving, setSaving] = useState(false);
  const [page, setPage] = useState<PageRow | null>(null);
  const [sections, setSections] = useState<SectionRow[]>([]);

  const load = async () => {
    setLoading(true);
    const [pRes, sRes] = await Promise.all([
      supabase.from("public_pages").select("*").eq("id", pageId).maybeSingle(),
      supabase.from("public_page_sections").select("*").eq("page_id", pageId).order("sort_order", { ascending: true }),
    ]);
    if (pRes.data) setPage(pRes.data as PageRow);
    setSections((sRes.data ?? []) as SectionRow[]);
    setLoading(false);
  };

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

  const savePage = async () => {
    if (!page) return;
    setSaving(true);
    const updates: any = {
      title: page.title, slug: page.slug, meta_description: page.meta_description,
      status: page.status, show_in_nav: page.show_in_nav, sort_order: page.sort_order,
    };
    if (page.status === "published") updates.published_at = new Date().toISOString();
    const { error } = await supabase.from("public_pages").update(updates).eq("id", pageId);
    setSaving(false);
    if (error) { toast.error("Could not save", { description: error.message }); return; }
    toast.success("Page saved");
  };

  const addSection = async (type: string) => {
    const sort_order = sections.length > 0 ? Math.max(...sections.map(s => s.sort_order)) + 1 : 0;
    const { data, error } = await supabase
      .from("public_page_sections")
      .insert({ page_id: pageId, section_type: type, sort_order, content: defaultContent(type) })
      .select("*").single();
    if (error) { toast.error("Could not add section", { description: error.message }); return; }
    setSections([...sections, data as SectionRow]);
  };

  const updateSection = (id: string, content: any) => {
    setSections(sections.map(s => s.id === id ? { ...s, content } : s));
  };

  const persistSection = async (id: string) => {
    const s = sections.find(x => x.id === id);
    if (!s) return;
    const { error } = await supabase.from("public_page_sections").update({ content: s.content }).eq("id", id);
    if (error) toast.error("Could not save section", { description: error.message });
    else toast.success("Section saved");
  };

  const removeSection = async (id: string) => {
    if (!confirm("Delete this section?")) return;
    const { error } = await supabase.from("public_page_sections").delete().eq("id", id);
    if (error) { toast.error("Could not delete", { description: error.message }); return; }
    setSections(sections.filter(s => s.id !== id));
  };

  const move = async (id: string, dir: -1 | 1) => {
    const idx = sections.findIndex(s => s.id === id);
    const swapIdx = idx + dir;
    if (swapIdx < 0 || swapIdx >= sections.length) return;
    const a = sections[idx]; const b = sections[swapIdx];
    const newSections = [...sections];
    newSections[idx] = { ...b, sort_order: a.sort_order };
    newSections[swapIdx] = { ...a, sort_order: b.sort_order };
    setSections(newSections);
    await Promise.all([
      supabase.from("public_page_sections").update({ sort_order: b.sort_order }).eq("id", a.id),
      supabase.from("public_page_sections").update({ sort_order: a.sort_order }).eq("id", b.id),
    ]);
  };

  if (!isAdmin) return <p className="text-sm text-muted-foreground">Admins only.</p>;
  if (loading) return <div className="flex justify-center py-10"><Loader2 className="h-5 w-5 animate-spin" /></div>;
  if (!page) return <p className="text-sm text-muted-foreground">Page not found.</p>;

  return (
    <div className="space-y-6">
      <div className="flex items-center justify-between">
        <Button variant="ghost" size="sm" asChild>
          <Link to="/settings/public-pages"><ArrowLeft className="h-4 w-4 mr-2" />All pages</Link>
        </Button>
        <div className="flex gap-2">
          {page.status === "published" && (
            <Button variant="outline" size="sm" asChild>
              <a href={`/p/${page.slug}`} target="_blank" rel="noreferrer"><ExternalLink className="h-4 w-4 mr-2" />View</a>
            </Button>
          )}
          <Button onClick={savePage} disabled={saving}>
            {saving ? <Loader2 className="h-4 w-4 mr-2 animate-spin" /> : <Save className="h-4 w-4 mr-2" />}
            Save page
          </Button>
        </div>
      </div>

      <Card>
        <CardHeader><CardTitle className="text-base">Page settings</CardTitle></CardHeader>
        <CardContent className="space-y-3">
          <div className="grid sm:grid-cols-2 gap-3">
            <div>
              <Label>Title</Label>
              <Input value={page.title} onChange={(e) => setPage({ ...page, title: e.target.value })} />
            </div>
            <div>
              <Label>Slug</Label>
              <Input value={page.slug} onChange={(e) => setPage({ ...page, slug: e.target.value.toLowerCase().replace(/[^a-z0-9-]/g, "") })} />
            </div>
          </div>
          <div>
            <Label>Meta description (SEO)</Label>
            <Textarea rows={2} value={page.meta_description ?? ""} onChange={(e) => setPage({ ...page, meta_description: e.target.value })} />
          </div>
          <div className="grid sm:grid-cols-3 gap-3">
            <div>
              <Label>Status</Label>
              <Select value={page.status} onValueChange={(v) => setPage({ ...page, status: v })}>
                <SelectTrigger><SelectValue /></SelectTrigger>
                <SelectContent>
                  <SelectItem value="draft">Draft</SelectItem>
                  <SelectItem value="published">Published</SelectItem>
                </SelectContent>
              </Select>
            </div>
            <div>
              <Label>Sort order</Label>
              <Input type="number" value={page.sort_order} onChange={(e) => setPage({ ...page, sort_order: parseInt(e.target.value) || 0 })} />
            </div>
            <div className="flex items-end gap-2 pb-2">
              <Switch checked={page.show_in_nav} onCheckedChange={(v) => setPage({ ...page, show_in_nav: v })} id="nav" />
              <Label htmlFor="nav">Show in nav</Label>
            </div>
          </div>
        </CardContent>
      </Card>

      <Card>
        <CardHeader>
          <div className="flex items-center justify-between">
            <CardTitle className="text-base">Sections</CardTitle>
            <Select onValueChange={addSection}>
              <SelectTrigger className="w-[220px]"><SelectValue placeholder="+ Add section" /></SelectTrigger>
              <SelectContent>
                {SECTION_TYPES.map(t => <SelectItem key={t.value} value={t.value}>{t.label}</SelectItem>)}
              </SelectContent>
            </Select>
          </div>
        </CardHeader>
        <CardContent className="space-y-4">
          {sections.length === 0 && (
            <p className="text-sm text-muted-foreground text-center py-6">No sections yet. Add one above.</p>
          )}
          {sections.map((s, i) => (
            <Card key={s.id} className="border-2">
              <CardHeader className="pb-3">
                <div className="flex items-center justify-between">
                  <div className="flex items-center gap-2">
                    <Badge variant="outline">{SECTION_TYPES.find(t => t.value === s.section_type)?.label ?? s.section_type}</Badge>
                  </div>
                  <div className="flex items-center gap-1">
                    <Button variant="ghost" size="sm" onClick={() => move(s.id, -1)} disabled={i === 0}><ChevronUp className="h-4 w-4" /></Button>
                    <Button variant="ghost" size="sm" onClick={() => move(s.id, 1)} disabled={i === sections.length - 1}><ChevronDown className="h-4 w-4" /></Button>
                    <Button variant="ghost" size="sm" onClick={() => persistSection(s.id)}><Save className="h-4 w-4" /></Button>
                    <Button variant="ghost" size="sm" onClick={() => removeSection(s.id)}><Trash2 className="h-4 w-4 text-destructive" /></Button>
                  </div>
                </div>
              </CardHeader>
              <CardContent>
                <SectionEditor section={s} onChange={(c) => updateSection(s.id, c)} />
              </CardContent>
            </Card>
          ))}
        </CardContent>
      </Card>
    </div>
  );
}

function SectionEditor({ section, onChange }: { section: SectionRow; onChange: (c: any) => void }) {
  const c = section.content || {};
  const upd = (patch: any) => onChange({ ...c, ...patch });

  const uploadImage = async (file: File): Promise<string | null> => {
    const ext = file.name.split(".").pop() || "png";
    const path = `${Date.now()}-${Math.random().toString(36).slice(2, 8)}.${ext}`;
    const { error } = await supabase.storage.from("public-page-images").upload(path, file, { upsert: false, contentType: file.type });
    if (error) { toast.error("Upload failed", { description: error.message }); return null; }
    const { data } = supabase.storage.from("public-page-images").getPublicUrl(path);
    return data.publicUrl;
  };

  switch (section.section_type) {
    case "hero":
      return (
        <div className="space-y-3">
          <div><Label>Eyebrow (small label above heading)</Label><Input value={c.eyebrow ?? ""} onChange={(e) => upd({ eyebrow: e.target.value })} /></div>
          <div><Label>Heading</Label><Input value={c.heading ?? ""} onChange={(e) => upd({ heading: e.target.value })} /></div>
          <div><Label>Subheading</Label><Textarea rows={2} value={c.subheading ?? ""} onChange={(e) => upd({ subheading: e.target.value })} /></div>
        </div>
      );
    case "rich_text":
      return (
        <div className="space-y-2">
          <div className="flex items-center gap-2">
            <Label>Body</Label>
            <Button type="button" variant="outline" size="sm" onClick={() => {
              const input = document.createElement("input");
              input.type = "file"; input.accept = "image/*";
              input.onchange = async () => {
                const file = input.files?.[0]; if (!file) return;
                const url = await uploadImage(file);
                if (url) upd({ html: (c.html ?? "") + `<p><img src="${url}" alt="" style="max-width:100%;" /></p>` });
              };
              input.click();
            }}><ImageIcon className="h-4 w-4 mr-2" />Insert image</Button>
          </div>
          <RichTextEditor value={c.html ?? ""} onChange={(html) => upd({ html })} minHeight={250} />
        </div>
      );
    case "feature_grid": {
      const items = Array.isArray(c.items) ? c.items : [];
      return (
        <div className="space-y-3">
          <div><Label>Heading</Label><Input value={c.heading ?? ""} onChange={(e) => upd({ heading: e.target.value })} /></div>
          <div className="space-y-2">
            {items.map((it: any, idx: number) => (
              <div key={idx} className="flex gap-2 items-start border rounded-md p-2">
                <div className="flex-1 space-y-2">
                  <Input placeholder="Title" value={it.title ?? ""} onChange={(e) => {
                    const next = [...items]; next[idx] = { ...it, title: e.target.value }; upd({ items: next });
                  }} />
                  <Textarea rows={2} placeholder="Description" value={it.body ?? ""} onChange={(e) => {
                    const next = [...items]; next[idx] = { ...it, body: e.target.value }; upd({ items: next });
                  }} />
                </div>
                <Button variant="ghost" size="sm" onClick={() => upd({ items: items.filter((_: any, i: number) => i !== idx) })}><X className="h-4 w-4" /></Button>
              </div>
            ))}
            <Button variant="outline" size="sm" onClick={() => upd({ items: [...items, { title: "", body: "" }] })}><Plus className="h-4 w-4 mr-2" />Add feature</Button>
          </div>
        </div>
      );
    }
    case "cta":
      return (
        <div className="space-y-3">
          <div><Label>Heading</Label><Input value={c.heading ?? ""} onChange={(e) => upd({ heading: e.target.value })} /></div>
          <div><Label>Subheading</Label><Textarea rows={2} value={c.subheading ?? ""} onChange={(e) => upd({ subheading: e.target.value })} /></div>
          <div className="grid sm:grid-cols-2 gap-3">
            <div><Label>Button label</Label><Input value={c.button_label ?? ""} onChange={(e) => upd({ button_label: e.target.value })} /></div>
            <div><Label>Button URL</Label><Input value={c.button_url ?? ""} onChange={(e) => upd({ button_url: e.target.value })} /></div>
          </div>
        </div>
      );
    case "contact":
      return (
        <div className="space-y-3">
          <div><Label>Heading</Label><Input value={c.heading ?? ""} onChange={(e) => upd({ heading: e.target.value })} /></div>
          <div className="grid sm:grid-cols-2 gap-3">
            <div><Label>Phone</Label><Input value={c.phone ?? ""} onChange={(e) => upd({ phone: e.target.value })} /></div>
            <div><Label>Email</Label><Input value={c.email ?? ""} onChange={(e) => upd({ email: e.target.value })} /></div>
          </div>
          <div><Label>Address</Label><Textarea rows={2} value={c.address ?? ""} onChange={(e) => upd({ address: e.target.value })} /></div>
        </div>
      );
    case "faq": {
      const items = Array.isArray(c.items) ? c.items : [];
      return (
        <div className="space-y-3">
          <div><Label>Heading</Label><Input value={c.heading ?? ""} onChange={(e) => upd({ heading: e.target.value })} /></div>
          <div className="space-y-2">
            {items.map((it: any, idx: number) => (
              <div key={idx} className="flex gap-2 items-start border rounded-md p-2">
                <div className="flex-1 space-y-2">
                  <Input placeholder="Question" value={it.q ?? ""} onChange={(e) => {
                    const next = [...items]; next[idx] = { ...it, q: e.target.value }; upd({ items: next });
                  }} />
                  <Textarea rows={2} placeholder="Answer" value={it.a ?? ""} onChange={(e) => {
                    const next = [...items]; next[idx] = { ...it, a: e.target.value }; upd({ items: next });
                  }} />
                </div>
                <Button variant="ghost" size="sm" onClick={() => upd({ items: items.filter((_: any, i: number) => i !== idx) })}><X className="h-4 w-4" /></Button>
              </div>
            ))}
            <Button variant="outline" size="sm" onClick={() => upd({ items: [...items, { q: "", a: "" }] })}><Plus className="h-4 w-4 mr-2" />Add Q&amp;A</Button>
          </div>
        </div>
      );
    }
    default: return <p className="text-sm text-muted-foreground">Unknown section type.</p>;
  }
}