#!/usr/bin/env bash

set -euo pipefail

die() { echo "$*" >&2; exit 1; }

vol_name() { echo "${1% *}"; }
vol_dir() { echo "${1#* }"; }

make_test_vols() {
  vols=()
  deleted_vols=()
  for (( i=0; i<$1; i++ ));do
    vol=$(mktemp -d)
    name="r$i"
    if (( i == 0 ));then
      git -C "$vol" init
      git -C "$vol" commit --allow-empty -m "Begin"
    else
      git clone "$(vol_dir "${vols[0]}")" "$vol"
      git -C "$vol" remote remove origin
    fi
    git -C "$vol" annex init "$name"
    vols+=( "$name $vol" )
  done
  for vol in "${vols[@]}";do
    for r in "${vols[@]}";do
      if [[ "$vol" != "$r" ]];then
        git -C "$(vol_dir "$vol")" remote add "$(vol_name "$r")" "$(vol_dir "$r")"
      fi
    done
  done
  sync_everything
}

sync_everything() {
  for vol in "${vols[@]}";do
    for already_deleted in "${deleted_vols[@]}";do
      if [[ "$vol" == "$already_deleted" ]];then continue 2; fi
    done
    git -C "$(vol_dir "$vol")" annex sync
  done
}

fsck_everything() {
  for vol in "${vols[@]}";do
    for already_deleted in "${deleted_vols[@]}";do
      if [[ "$vol" == "$already_deleted" ]];then continue 2; fi
    done
    git -C "$(vol_dir "$vol")" annex fsck
  done
}

delete_test_vol() {
  for already_deleted in "${deleted_vols[@]}";do
    if [[ "$1" == "$already_deleted" ]];then return; fi
  done
  d="$(vol_dir "$1")"
  if [[ -d "$d/.git/annex/objects" ]];then
    chmod -R +w "$d/.git/annex/objects"
  fi
  rm -rf "$d"
  deleted_vols+=( "$1" )

  # Find a not-yet-deleted volume (if there is one) and report the deleted volume as dead
  for vol in "${vols[@]}";do
    for already_deleted in "${deleted_vols[@]}";do
      if [[ "$vol" == "$already_deleted" ]];then continue 2; fi
    done
    git -C "$(vol_dir "$vol")" annex dead "$(vol_name "$1")"
    break
  done
}

delete_some_test_vols() {
  while read -r vol;do
    delete_test_vol "$vol"
  done < <(for vol in "${vols[@]}";do
             echo "$vol"
           done | shuf | head -n "$1")
}

delete_all_test_vols() {
  for vol in "${vols[@]}";do
    delete_test_vol "$vol"
  done
  vols=()
  deleted_vols=()
}

make_test_file() {
  name=$(tr -cd 0-9a-f < /dev/urandom | head -c 32)
  size=$((RANDOM + RANDOM))
  f="$name-$size"
  set +o pipefail
  openssl aes-128-cbc -nosalt -iv 0 -K "$name" < /dev/zero | head -c "$size" > "$1/$f"
  set -o pipefail
  git -C "$1" annex add "$f" >&2
  echo "$f"
}

choose_volumes() {
  x=$(for vol in "${vols[@]}";do
        vol_name "$vol"
      done | shuf | head -n "$1" | tr \\n ,)
  echo "${x%,}"
}

MIN_REDUNDANCY=1
MIN_FILES=2 # If you only have one file in a group, you'd just make copies of it, no need for annex-ec
MIN_VOLUMES=$((MIN_REDUNDANCY + MIN_FILES))

for (( num_vols=MIN_VOLUMES; num_vols <= 10; num_vols++ ));do
  for (( redundancy=1; redundancy < num_vols-2; redundancy++ ));do
    max_files=$(( num_vols - redundancy ))
    for (( num_files=MIN_FILES; num_files <= max_files; num_files++ ));do
      make_test_vols "$num_vols"
      files=()
      for (( i=0; i < num_files; i++ )); do
        files[i]=$(make_test_file "$(vol_dir "${vols[i]}")")
      done
      sync_everything
      sync_everything
      pushd "$(vol_dir "${vols[$RANDOM % $num_vols]}")"
        cmd=(annex-ec -r "$redundancy" -v "$(choose_volumes $((num_files+redundancy)))" "${files[@]}")
        echo "In $PWD , running ${cmd[*]}" >&2
        "${cmd[@]}"
      popd
      sync_everything
      fsck_everything
      delete_some_test_vols "$redundancy"
      # TODO: Recover
      sync_everything
      # fsck_everything # Skip this check until recovery is implemented
      delete_all_test_vols
    done
  done
done