import { createClient } from '@/lib/supabase/server';
import { NextRequest, NextResponse } from 'next/server';

// GET: list all templates
export async function GET() {
  const supabase = await createClient();
  const { data: { user } } = await supabase.auth.getUser();
  if (!user) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });

  const { data, error } = await supabase
    .from('newsletter_templates')
    .select('*')
    .order('is_preset', { ascending: false })
    .order('created_at', { ascending: true });

  if (error) return NextResponse.json({ error: error.message }, { status: 500 });
  return NextResponse.json({ templates: data || [] });
}

// POST: create a new template
export async function POST(req: NextRequest) {
  const supabase = await createClient();
  const { data: { user } } = await supabase.auth.getUser();
  if (!user) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });

  const body = await req.json();
  const { name, description, layout, style, subject_prefix, header_text, footer_text, accent_color, article_blocks } = body;

  if (!name?.trim()) return NextResponse.json({ error: 'Name is required' }, { status: 400 });

  const { data, error } = await supabase
    .from('newsletter_templates')
    .insert({
      name: name.trim(),
      description: description || '',
      layout: layout || 'standard',
      style: style || 'dark',
      subject_prefix: subject_prefix || '',
      header_text: header_text || '',
      footer_text: footer_text || '',
      accent_color: accent_color || '#1D4ED8',
      article_blocks: article_blocks || [],
      is_preset: false,
    })
    .select()
    .single();

  if (error) return NextResponse.json({ error: error.message }, { status: 500 });
  return NextResponse.json({ template: data });
}

// PUT: update a template
export async function PUT(req: NextRequest) {
  const supabase = await createClient();
  const { data: { user } } = await supabase.auth.getUser();
  if (!user) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });

  const body = await req.json();
  const { id, ...updates } = body;
  if (!id) return NextResponse.json({ error: 'ID required' }, { status: 400 });

  const { data, error } = await supabase
    .from('newsletter_templates')
    .update({ ...updates, updated_at: new Date().toISOString() })
    .eq('id', id)
    .select()
    .single();

  if (error) return NextResponse.json({ error: error.message }, { status: 500 });
  return NextResponse.json({ template: data });
}

// DELETE: remove a template (only non-preset)
export async function DELETE(req: NextRequest) {
  const supabase = await createClient();
  const { data: { user } } = await supabase.auth.getUser();
  if (!user) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });

  const { id } = await req.json();
  if (!id) return NextResponse.json({ error: 'ID required' }, { status: 400 });

  // Prevent deleting presets
  const { data: tpl } = await supabase
    .from('newsletter_templates')
    .select('is_preset')
    .eq('id', id)
    .single();

  if (tpl?.is_preset) {
    return NextResponse.json({ error: 'Cannot delete preset templates' }, { status: 403 });
  }

  const { error } = await supabase.from('newsletter_templates').delete().eq('id', id);
  if (error) return NextResponse.json({ error: error.message }, { status: 500 });
  return NextResponse.json({ success: true });
}