const axios = require('axios')
const PostModel = require('../models/PostModel')
const InstagramImportedPostModel = require('../models/InstagramImportedPostModel')
const { saveBase64PostFiles } = require('./postBase64Files')
const { resolvePostModerationStatus } = require('./contentModeration')
const { savePostWithModerationStatus } = require('./postStatusSave')
const path = require('path')

const imageDir = path.join(__dirname, '../storage/posts/images')
const videoDir = path.join(__dirname, '../storage/posts/videos')

/**
 * CAROUSEL_ALBUM items need a second Graph API call (children edge) to resolve
 * each slide's own media_url — intentionally out of scope for v1, single
 * image/video posts only.
 */
const SUPPORTED_MEDIA_TYPES = ['IMAGE', 'VIDEO']

async function downloadMediaAsFile (mediaUrl, mediaType) {
  const response = await axios.get(mediaUrl, {
    responseType: 'arraybuffer',
    timeout: 20000,
  })
  const contentType =
    response.headers['content-type'] ||
    (mediaType === 'VIDEO' ? 'video/mp4' : 'image/jpeg')
  const base64Data = `data:${contentType};base64,${Buffer.from(response.data).toString('base64')}`
  const ext = mediaType === 'VIDEO' ? 'mp4' : 'jpg'

  return {
    data: base64Data,
    type: contentType,
    name: `instagram-import.${ext}`,
  }
}

/**
 * Imports one Instagram media item as a Modstagram post, if not already imported
 * and if its type is supported. Shared by the manual/automatic import endpoints
 * and the recurring sync cron — same dedup + storage + moderation path either way.
 * Returns the created post, or null if the item was skipped (already imported /
 * unsupported type).
 */
async function importInstagramMedia (user, mediaItem) {
  if (!SUPPORTED_MEDIA_TYPES.includes(mediaItem.media_type)) {
    return null
  }
  if (!mediaItem.media_url) {
    return null
  }

  const alreadyImported = await InstagramImportedPostModel.findOne({
    user: user._id,
    instagram_media_id: String(mediaItem.id),
  })
  if (alreadyImported) {
    return null
  }

  const file = await downloadMediaAsFile(mediaItem.media_url, mediaItem.media_type)
  const [savedFile] = await saveBase64PostFiles([file], imageDir, videoDir)

  const filePaths = [
    {
      path: savedFile.path,
      type: savedFile.mimetype.startsWith('video/') ? 'video' : 'image',
    },
  ]

  const captionText = mediaItem.caption ? String(mediaItem.caption).trim().slice(0, 2000) : null
  const moderation = resolvePostModerationStatus({ caption: captionText, filePaths })
  if (moderation.status === 'reject') {
    return null
  }

  const post = await savePostWithModerationStatus(PostModel, {
    user_id: user._id,
    caption: captionText,
    files: filePaths,
    type: filePaths[0].type,
    status: moderation.status,
  })

  await InstagramImportedPostModel.create({
    user: user._id,
    instagram_media_id: String(mediaItem.id),
    post: post._id,
  })

  return post
}

module.exports = { importInstagramMedia, SUPPORTED_MEDIA_TYPES }