import dayjs from 'dayjs'
import { deburr } from 'lodash'

import { IMI_ORGANIZATIONS } from './config/imi'
import {
  AttributeFileValue,
  ExternalFile,
  isExternalFile,
  isRemoteFile,
} from './interfaces'

export const removeExtension = (filename: string) => {
  return filename.substring(0, filename.lastIndexOf('.')) || filename
}
export const getExtension = (filename: string) => {
  return filename.substring(filename.lastIndexOf('.') + 0)
}

export const FILE_TIMESTAMP_REGEX = /\s\(\d{2}\.\d{2}\.\d{2}.+\)/gm

// Matches an MD5-looking prefix ("<32 hex chars>.") that shouldn't be part of a
// user-facing filename. Local cache files are sometimes named this way internally
// (hash-prefixed, for on-device dedup); if one is ever picked up as an upload, this
// keeps the prefix from being carried forward into every later renamed revision.
const LEAKED_HASH_PREFIX_REGEX = /^[0-9a-f]{32}\./i
const stripLeakedHashPrefix = (filename: string): string =>
  filename.replace(LEAKED_HASH_PREFIX_REGEX, '')

export const findFileNameConflicts = (
  organization: string,
  original: (AttributeFileValue | ExternalFile)[],
  added: string[],
): { added: string[]; conflictHashes: string[] } => {
  return IMI_ORGANIZATIONS.includes(organization)
    ? resolveFileNameConfictsIMI(original, added)
    : resolveFileNameConflictsGlobal(original, added)
}

export const resolveFileNameConflictsGlobal = (
  original: (AttributeFileValue | ExternalFile)[],
  added: string[],
): { added: string[]; conflictHashes: string[] } => {
  const conflictHashes: string[] = []
  const concated = original
    .map((f) => (isRemoteFile(f) ? f.file.filename : f.name))
    .concat(added)
  const count: { [key: string]: number } = {}
  concated.forEach(function (x, i) {
    if (concated.indexOf(x) !== i) {
      const c = x in count ? (count[x] = count[x] + 1) : (count[x] = 1)
      const withoutExtension = removeExtension(x)
      const extension = getExtension(x)

      let j = c + 1
      let newName = withoutExtension + '(' + j + ')' + extension

      while (concated.indexOf(newName) !== -1) {
        newName = withoutExtension + '(' + ++j + ')' + extension
      }

      const originalFile = original.find((f) =>
        isRemoteFile(f) ? f.file.filename === x : f.name === x,
      )

      // skip checking for conflicts in external files
      if (originalFile && isRemoteFile(originalFile)) {
        conflictHashes.push(originalFile.file.hash)
      }
      concated[i] = newName
    }
  })
  concated.splice(0, original.length)
  return {
    added: concated,
    conflictHashes,
  }
}

export const resolveFileNameConfictsIMI = (
  original: (AttributeFileValue | ExternalFile)[],
  added: string[],
): { added: string[]; conflictHashes: string[] } => {
  const conflictHashes: string[] = []
  const addedChanged = added.map((file) => {
    const cleanedFileName = stripLeakedHashPrefix(
      deburr(file.replace(FILE_TIMESTAMP_REGEX, '')),
    )

    let hasConflict = false
    original.forEach((f) => {
      if (isRemoteFile(f)) {
        const cleanedOldFilename = stripLeakedHashPrefix(
          deburr(f.file.filename.replace(FILE_TIMESTAMP_REGEX, '')),
        )

        const isConflict = cleanedFileName === cleanedOldFilename

        if (isConflict && !conflictHashes.includes(f.file.hash)) {
          conflictHashes.push(f.file.hash)
          hasConflict = true
        }
      } else if (isExternalFile(f)) {
        const cleanedOldFilename = stripLeakedHashPrefix(
          deburr(f.name.replace(FILE_TIMESTAMP_REGEX, '')),
        )

        const isConflict = cleanedFileName === cleanedOldFilename

        if (isConflict && !conflictHashes.includes(f.md5)) {
          // external files are not stored in the database, so we do not compute hash conflicts

          hasConflict = true
        }
      }
    })

    if (hasConflict) {
      const timestamp = dayjs().format('DD.MM.YY HH:mm:ss')
      const ext = getExtension(cleanedFileName)
      const firstPart = removeExtension(cleanedFileName)

      return `${firstPart} (${timestamp})${ext}`
    } else {
      return file
    }
  })

  return {
    added: addedChanged,
    conflictHashes,
  }
}