const attachmentTypes = Object.freeze({
  image: ["image/png", "image/jpeg", "image/gif"]
})

async function getRecentMedia(context, limit) {
  if (!context.message.channel) {
    return undefined;
  } else if (context.message.attachments.length > 0) {
    return [context.message.attachments.first()]
  }

  let messages = [];

  // Handle Replies
  if (context.message.messageReference) {
    messages = [[context.message.messageReference.messageId, await context.message.channel.fetchMessage(context.message.messageReference.messageId)]] // somewhat hacky but it works lol
  } else {
    messages = await context.message.channel.fetchMessages({
      limit: limit,
      before: context.message.id
    })
  }

  if (!messages) {
    return undefined;
  }

  let attachments = [];
  for (const m of messages) {
    let message = m[1]
    if ( // First the attachment on the message
      message.attachments.first()
    ) {
      attachments.push(message.attachments.first())
    } else if ( // Then the embed image
      message.embeds.length > 0 &&
      message.embeds.toArray()[0].image
    ) {
      attachments.push(message.embeds.toArray()[0].image)
    } else if (
      message.embeds.length > 0 &&
      message.embeds.toArray()[0].thumbnail
    ) { attachments.push(message.embeds.toArray()[0].thumbnail) }
  }
  return attachments;
}


async function getRecentVideo(context, limit) {
  if (!context.message.channel) {
    return undefined;
  }

  // Handle Replies
  if (context.message.messageReference) {
    messages = [[context.message.messageReference.messageId, await context.message.channel.fetchMessage(context.message.messageReference.messageId)]] // somewhat hacky but it works lol
  } else {
    messages = await context.message.channel.fetchMessages({
      limit: limit,
      before: context.message.id
    })
  }

  if (!messages) {
    return undefined;
  }

  let attachments = [];
  for (const m of messages) {
    let message = m[1]
    if ( // Then the embed image
      message.embeds.length > 0 &&
      message.embeds.toArray()[0].video
    ) {
      attachments.push(message.embeds.toArray()[0].video)
    }
  }
  return attachments;
}

async function getRecentImage(context, limit) {
  let attachments = await getRecentMedia(context, limit)
  let at;
  let validImages = attachmentTypes.image
  for (const a of attachments) {
    if (a.contentType && validImages.includes(a.contentType) && at === undefined) { // discord attachment
      at = a.url
    } else if (!a.content_type && at === undefined) { // other form of media
      at = a.url
    }
  }
  return at;
}

module.exports = {
  getRecentImage,
  getRecentVideo
}