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

export async function handleComponents(req: Request) {
  const url = new URL(req.url)

  if (req.method === 'GET') {
    const includeArchived = url.searchParams.get('include_archived') === 'true'
    const limit = parseInt(url.searchParams.get('limit') || '0') || 0

    let sql = 'SELECT * FROM vue_components'
    const params: any[] = []

    if (!includeArchived) {
      sql += " WHERE (status = 'active' OR status IS NULL)"
    }

    sql += ' ORDER BY updated_at DESC'

    if (limit > 0) {
      sql += ' LIMIT ?'
      params.push(limit)
    }

    const rows = db.query(sql).all(...params)
    return jsonResponse(rows)
  }

  if (req.method === 'POST') {
    const body = await req.json()
    const id = body.id || `comp-${Date.now()}`
    const tags = body.tags ? JSON.stringify(body.tags) : null

    const stmt = db.prepare(`
      INSERT INTO vue_components (id, name, template, setup, style, props, imports, tags, status, updated_at)
      VALUES (?, ?, ?, ?, ?, ?, ?, ?, 'active', CURRENT_TIMESTAMP)
      ON CONFLICT(id) DO UPDATE SET
        name = excluded.name,
        template = excluded.template,
        setup = excluded.setup,
        style = excluded.style,
        props = excluded.props,
        imports = excluded.imports,
        tags = COALESCE(excluded.tags, tags),
        updated_at = CURRENT_TIMESTAMP
    `)
    stmt.run(
      id,
      body.name,
      body.template,
      body.setup || '',
      body.style || '',
      JSON.stringify(body.props || []),
      JSON.stringify(body.imports || []),
      tags
    )
    return jsonResponse({ success: true, id })
  }

  if (req.method === 'DELETE') {
    db.run("UPDATE vue_components SET status = 'archived', updated_at = CURRENT_TIMESTAMP")
    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 === 'PUT') {
    const body = await req.json()
    const fields: string[] = []
    const params: any[] = []

    const allowedFields = ['name', 'template', 'setup', 'style', 'props', 'imports', 'tags', 'status']
    for (const field of allowedFields) {
      if (body[field] !== undefined) {
        if (field === 'props' || field === 'imports' || field === 'tags') {
          fields.push(`${field} = ?`)
          params.push(JSON.stringify(body[field]))
        } else {
          fields.push(`${field} = ?`)
          params.push(body[field])
        }
      }
    }

    if (fields.length === 0) {
      return errorResponse('No fields to update', 400)
    }

    fields.push('updated_at = CURRENT_TIMESTAMP')
    params.push(id)

    db.run(`UPDATE vue_components SET ${fields.join(', ')} WHERE id = ?`, params)
    return jsonResponse({ success: true })
  }

  if (req.method === 'DELETE') {
    // Check if component is in use by any canvas (warn only)
    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 }[]

    db.run("UPDATE vue_components SET status = 'archived', updated_at = CURRENT_TIMESTAMP WHERE id = ?", [id])
    return jsonResponse({
      success: true,
      warning: usage.length > 0
        ? `Component is used by: ${usage.map(u => u.name).join(', ')}`
        : undefined
    })
  }

  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
  })
}