import { db } from '../db'
import { jsonResponse, errorResponse } from '../utils/cors'

export async function handleComponents(req: Request) {
  if (req.method === 'GET') {
    const rows = db.query('SELECT * FROM vue_components ORDER BY updated_at DESC').all()
    return jsonResponse(rows)
  }

  if (req.method === 'POST') {
    const body = await req.json()
    const id = body.id || `comp-${Date.now()}`
    const stmt = db.prepare(`
      INSERT OR REPLACE INTO vue_components
      (id, name, template, setup, style, props, imports, updated_at)
      VALUES (?, ?, ?, ?, ?, ?, ?, CURRENT_TIMESTAMP)
    `)
    stmt.run(
      id,
      body.name,
      body.template,
      body.setup || '',
      body.style || '',
      JSON.stringify(body.props || []),
      JSON.stringify(body.imports || [])
    )
    return jsonResponse({ success: true, id })
  }

  if (req.method === 'DELETE') {
    db.run('DELETE FROM vue_components')
    return jsonResponse({ success: true })
  }

  return null
}

export async function handleComponentById(req: Request, id: string) {
  if (req.method === 'GET') {
    const row = db.query('SELECT * FROM vue_components WHERE id = ?').get(id)
    if (!row) {
      return errorResponse('Component not found', 404)
    }
    return jsonResponse(row)
  }

  if (req.method === 'DELETE') {
    // Check if component is in use by any canvas
    const usage = db.query(`
      SELECT pc.id, pc.name
      FROM canvas_components cc
      JOIN project_canvas pc ON cc.canvas_id = pc.id
      WHERE cc.component_id = ?
    `).all(id) as { id: string; name: string }[]

    if (usage.length > 0) {
      return jsonResponse({
        error: 'Component in use',
        message: `Cannot delete component. It is used by: ${usage.map(u => u.name).join(', ')}`,
        usedBy: usage
      }, 409)
    }

    db.run('DELETE FROM vue_components WHERE id = ?', [id])
    return jsonResponse({ success: true })
  }

  return null
}

export function handleComponentUsage(componentId: string) {
  const usage = db.query(`
    SELECT pc.id, pc.name, pc.type
    FROM canvas_components cc
    JOIN project_canvas pc ON cc.canvas_id = pc.id
    WHERE cc.component_id = ?
  `).all(componentId) as { id: string; name: string; type: string }[]

  return jsonResponse({
    componentId,
    usedBy: usage,
    canDelete: usage.length === 0
  })
}