#!/usr/bin/env bash

set -euo pipefail

BRANCH="update-inputs-$(date +%Y-%m-%d-%H-%M)"
HYDRA_URL="https://hydra.kyouma.net"
JOBSET_URL="${HYDRA_URL}/jobset/nixfiles/update-inputs"
ROOT="$(mktemp -d)"

gitin () {
  git -C "${ROOT}/nixfiles" "$@"
}

merge_theirs () {
  gitin merge -s ours "${BRANCH}" -m "Update from ${BRANCH}"
  gitin branch temp
  gitin reset --hard "${BRANCH}"
  gitin reset --soft temp
  gitin commit --amend --no-edit
  gitin branch -D temp
}

test_build () {
  local last_error
  local build_jobs
  local start_time
  start_time="$(date +%s)"

  build_jobs="$(curl --fail -s -L -H "Accept: application/json" "${JOBSET_URL}/latest-eval" | jq -r ".builds | .[]")"
  for build in ${build_jobs}; do 
    local build_status

    while true; do
      local build_finished
      build_finished="$(curl --fail -s -L -H "Accept: application/json" "${HYDRA_URL}/build/${build}" | jq -r ".finished")"
      [[ ${build_finished} == 1 ]] && break
      sleep 5
    done

    build_status="$(curl --fail -s -L -H "Accept: application/json" "${HYDRA_URL}/build/${build}" | jq -r ".buildstatus")"
    [[ $build_status != 0 ]] &&
      echo "Build ${build} failed" &&
      exit 1
    echo "Build ${build} was successful"
  done

  last_error="$(curl --fail -s -L -H "Accept: application/json" "${JOBSET_URL}" | jq -r ".errortime")"
  [[ $last_error -gt $start_time ]] && 
    echo "Evaluation error encountered at $(date +%Y-%m-%d-%H:%M:%S --date="@${last_error}")" &&
    exit 1
}

wait_for_hydra () {
  local git_rev
  local hydra_rev
  local counter
  counter=0
  git_rev="$(git -C "${1}/nixfiles" rev-parse update-inputs)"
  while true; do
    hydra_rev="$(curl -s -L -H "Accept: application/json" "${2}/latest-eval" | jq -r .flake | sed -E "s/.+&rev=(.*)/\1/g")"
    if [[ "${git_rev}" == "${hydra_rev}" ]]; then
      echo "Hydra got new commit"
      break
    fi
    sleep 30
  done
  if [[ $counter -ge 30 ]]; then 
    echo "Hydra no workey"
    exit 1
  fi
}

ssh-agent -a "${ROOT}/ssh-agent"
SSH_AUTH_SOCK="${ROOT}/ssh-agent"
export SSH_AUTH_SOCK
ssh-add "/run/secrets/services/update-nixfiles/privateKey"

git clone forgejo@woof.rip:emily/nixfiles.git "${ROOT}/nixfiles"
gitin fetch --all
gitin checkout origin/main

gitin checkout -b "${BRANCH}"

pushd "${ROOT}/nixfiles"
nix flake update --commit-lock-file
popd

if gitin diff --quiet origin/update-inputs "${BRANCH}"; then
  echo "No update needed"
  gitin checkout update-inputs
  gitin branch -D "${BRANCH}"
  exit 0
fi

gitin push --set-upstream origin "${BRANCH}"

gitin checkout update-inputs
merge_theirs 
gitin push origin update-inputs

echo "Waiting for hydra to get new commit"
export -f wait_for_hydra
timeout 4h bash -c "wait_for_hydra ${ROOT} ${JOBSET_URL}"

echo "Testing if all build jobs completed successfully"
test_build
echo "All build jobs were successful"

echo "Merging ${BRANCH} into main"
gitin checkout main
gitin merge --ff-only "${BRANCH}"
gitin push origin main

echo "Update successful"