import fs from 'fs/promises'
import path from 'path'
import sharp from 'sharp'

// Handle both dev and production paths
const getDataPath = (filename) => {
  const cwd = process.cwd()
  if (cwd.endsWith('.output')) {
    return path.join(cwd, '../server/data', filename)
  }
  return path.join(cwd, 'server/data', filename)
}

const PERSONEN_DIR = getDataPath('personen')

export default defineEventHandler(async (event) => {
  try {
    const filename = getRouterParam(event, 'filename')
    
    if (!filename) {
      throw createError({
        statusCode: 400,
        statusMessage: 'Dateiname erforderlich'
      })
    }

    // Sicherheitsprüfung: Nur erlaubte Dateinamen (UUID-Format)
    if (!/^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}\.(jpg|jpeg|png|gif|webp)$/i.test(filename)) {
      throw createError({
        statusCode: 400,
        statusMessage: 'Ungültiger Dateiname'
      })
    }

    const filePath = path.join(PERSONEN_DIR, filename)

    // Prüfe ob Datei existiert
    try {
      await fs.access(filePath)
    } catch {
      throw createError({
        statusCode: 404,
        statusMessage: 'Bild nicht gefunden'
      })
    }

    // MIME-Type bestimmen
    const ext = path.extname(filename).toLowerCase()
    const mimeTypes = {
      '.jpg': 'image/jpeg',
      '.jpeg': 'image/jpeg',
      '.png': 'image/png',
      '.gif': 'image/gif',
      '.webp': 'image/webp'
    }
    const contentType = mimeTypes[ext] || 'application/octet-stream'

    // Optional: Query-Parameter für Größe
    const query = getQuery(event)
    const width = query.width ? parseInt(query.width) : null
    const height = query.height ? parseInt(query.height) : null

    let imageBuffer = await fs.readFile(filePath)

    // Bild verarbeiten falls Größe angegeben
    if (width || height) {
      const resizeOptions = {}
      if (width && height) {
        resizeOptions.width = width
        resizeOptions.height = height
        resizeOptions.fit = 'cover'
      } else if (width) {
        resizeOptions.width = width
        resizeOptions.fit = 'inside'
        resizeOptions.withoutEnlargement = true
      } else if (height) {
        resizeOptions.height = height
        resizeOptions.fit = 'inside'
        resizeOptions.withoutEnlargement = true
      }

      imageBuffer = await sharp(imageBuffer)
        .rotate() // EXIF-Orientierung korrigieren
        .resize(resizeOptions)
        .toBuffer()
    } else {
      // Nur EXIF-Orientierung korrigieren
      imageBuffer = await sharp(imageBuffer).rotate().toBuffer()
    }

    setHeader(event, 'Content-Type', contentType)
    setHeader(event, 'Cache-Control', 'public, max-age=31536000')

    return imageBuffer
  } catch (error) {
    console.error('Fehler beim Laden des Personenfotos:', error)
    
    if (error.statusCode) {
      throw error
    }
    
    throw createError({
      statusCode: 500,
      statusMessage: 'Fehler beim Laden des Bildes'
    })
  }
})