#!/usr/bin/env bash
set -euo pipefail

export PATH="/run/current-system/sw/bin:/usr/bin:/bin:${PATH}"

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO_ROOT="$(cd "${SCRIPT_DIR}/../.." && pwd)"
WORK_ROOT="${ULTRACLOUD_WORK_ROOT:-${REPO_ROOT}/work}"
LOG_DIR="${1:-${ULTRACLOUD_KVM_PUBLISHABLE_LOG_DIR:-${WORK_ROOT}/publishable-kvm-suite}}"

mkdir -p "${LOG_DIR}"

log() {
  printf '[publishable-kvm-suite] %s\n' "$*"
}

die() {
  printf '[publishable-kvm-suite] ERROR: %s\n' "$*" >&2
  exit 1
}

host_cpu_count() {
  local count
  count="$(getconf _NPROCESSORS_ONLN 2>/dev/null || nproc 2>/dev/null || echo 1)"
  if [[ ! "${count}" =~ ^[0-9]+$ ]] || (( count < 1 )); then
    count=1
  fi
  printf '%s\n' "${count}"
}

default_local_nix_max_jobs() {
  local cpu_count="$1"
  if (( cpu_count <= 2 )); then
    printf '1\n'
    return 0
  fi

  printf '%s\n' "$(( (cpu_count + 1) / 2 ))"
}

default_local_nix_build_cores() {
  local cpu_count="$1"
  local max_jobs="$2"
  local build_cores=1

  if (( max_jobs > 0 )); then
    build_cores="$(( cpu_count / max_jobs ))"
  fi
  if (( build_cores < 1 )); then
    build_cores=1
  fi

  printf '%s\n' "${build_cores}"
}

append_nix_config_line() {
  local line="$1"
  if [[ -n "${NIX_CONFIG:-}" ]]; then
    NIX_CONFIG+=$'\n'
  fi
  NIX_CONFIG+="${line}"
}

host_nested_param_path() {
  if [[ -f /sys/module/kvm_intel/parameters/nested ]]; then
    printf '%s\n' /sys/module/kvm_intel/parameters/nested
  elif [[ -f /sys/module/kvm_amd/parameters/nested ]]; then
    printf '%s\n' /sys/module/kvm_amd/parameters/nested
  fi
}

require_publishable_kvm_host() {
  [[ -e /dev/kvm ]] || die "/dev/kvm is missing"
  [[ -r /dev/kvm && -w /dev/kvm ]] || die "/dev/kvm is not readable and writable for $(id -un)"

  local nested_path nested_value
  nested_path="$(host_nested_param_path || true)"
  if [[ -z "${nested_path}" ]]; then
    return 0
  fi

  nested_value="$(<"${nested_path}")"
  case "${nested_value}" in
    1|Y|y)
      ;;
    *)
      die "nested virtualization is disabled on the host (${nested_path}=${nested_value})"
      ;;
  esac
}

choose_runtime_root() {
  if [[ -n "${ULTRACLOUD_KVM_RUNTIME_ROOT:-}" ]]; then
    printf '%s\n' "${ULTRACLOUD_KVM_RUNTIME_ROOT}"
    return 0
  fi

  printf '%s\n' "${WORK_ROOT}/publishable-kvm-runtime"
}

get_hostname() {
  if command -v hostname >/dev/null 2>&1; then
    hostname
  else
    uname -n
  fi
}

prepare_runtime_dirs() {
  local runtime_root cpu_count default_max_jobs default_build_cores

  runtime_root="$(choose_runtime_root)"
  cpu_count="$(host_cpu_count)"
  default_max_jobs="$(default_local_nix_max_jobs "${cpu_count}")"
  default_build_cores="$(default_local_nix_build_cores "${cpu_count}" "${default_max_jobs}")"
  export ULTRACLOUD_KVM_RUNTIME_ROOT="${runtime_root}"
  export TMPDIR="${TMPDIR:-${WORK_ROOT}/tmp}"
  export XDG_CACHE_HOME="${XDG_CACHE_HOME:-${runtime_root}/xdg-cache}"
  export PHOTON_CLUSTER_WORK_ROOT="${PHOTON_CLUSTER_WORK_ROOT:-${WORK_ROOT}/test-cluster}"
  export PHOTON_VM_DIR="${PHOTON_VM_DIR:-${PHOTON_CLUSTER_WORK_ROOT}/state}"
  export PHOTON_CLUSTER_VDE_SWITCH_DIR="${PHOTON_CLUSTER_VDE_SWITCH_DIR:-${PHOTON_CLUSTER_WORK_ROOT}/vde-switch}"
  export ULTRACLOUD_LOCAL_NIX_MAX_JOBS="${ULTRACLOUD_LOCAL_NIX_MAX_JOBS:-${default_max_jobs}}"
  export ULTRACLOUD_LOCAL_NIX_BUILD_CORES="${ULTRACLOUD_LOCAL_NIX_BUILD_CORES:-${default_build_cores}}"
  export PHOTON_CLUSTER_NIX_MAX_JOBS="${PHOTON_CLUSTER_NIX_MAX_JOBS:-${ULTRACLOUD_LOCAL_NIX_MAX_JOBS}}"
  export PHOTON_CLUSTER_NIX_BUILD_CORES="${PHOTON_CLUSTER_NIX_BUILD_CORES:-${ULTRACLOUD_LOCAL_NIX_BUILD_CORES}}"
  export PHOTON_VM_SKIP_NESTED_KVM_VALIDATE=0
  export PHOTON_VM_FORCE_TCG=0
  append_nix_config_line "builders ="
  append_nix_config_line "max-jobs = ${ULTRACLOUD_LOCAL_NIX_MAX_JOBS}"
  append_nix_config_line "cores = ${ULTRACLOUD_LOCAL_NIX_BUILD_CORES}"
  append_nix_config_line "experimental-features = nix-command flakes"
  append_nix_config_line "warn-dirty = false"
  export NIX_CONFIG
  mkdir -p "${TMPDIR}" "${XDG_CACHE_HOME}" "${PHOTON_CLUSTER_WORK_ROOT}" "${PHOTON_CLUSTER_VDE_SWITCH_DIR}" "${runtime_root}"
}

capture_environment() {
  {
    printf 'started_at=%s\n' "$(date -Is)"
    printf 'hostname=%s\n' "$(get_hostname)"
    printf 'kernel=%s\n' "$(uname -a)"
    printf 'pwd=%s\n' "$(pwd)"
    printf 'user=%s\n' "$(id -un)"
    printf 'uid=%s\n' "$(id -u)"
    printf 'gid=%s\n' "$(id -g)"
    printf 'branch=%s\n' "$(git -C "${REPO_ROOT}" branch --show-current)"
    printf 'commit=%s\n' "$(git -C "${REPO_ROOT}" rev-parse HEAD)"
    printf 'nix_version=%s\n' "$(nix --version)"
    printf 'runtime_root=%s\n' "${ULTRACLOUD_KVM_RUNTIME_ROOT:-}"
    printf 'tmpdir=%s\n' "${TMPDIR:-}"
    printf 'xdg_cache_home=%s\n' "${XDG_CACHE_HOME:-}"
    printf 'photon_cluster_work_root=%s\n' "${PHOTON_CLUSTER_WORK_ROOT:-}"
    printf 'photon_vm_dir=%s\n' "${PHOTON_VM_DIR:-}"
    printf 'photon_cluster_vde_switch_dir=%s\n' "${PHOTON_CLUSTER_VDE_SWITCH_DIR:-}"
    printf 'host_cpu_count=%s\n' "$(host_cpu_count)"
    printf 'local_nix_max_jobs=%s\n' "${ULTRACLOUD_LOCAL_NIX_MAX_JOBS:-}"
    printf 'local_nix_build_cores=%s\n' "${ULTRACLOUD_LOCAL_NIX_BUILD_CORES:-}"
    printf 'photon_cluster_nix_max_jobs=%s\n' "${PHOTON_CLUSTER_NIX_MAX_JOBS:-}"
    printf 'photon_cluster_nix_build_cores=%s\n' "${PHOTON_CLUSTER_NIX_BUILD_CORES:-}"
    printf 'nested_kvm_validate_skipped=%s\n' "${PHOTON_VM_SKIP_NESTED_KVM_VALIDATE:-0}"
    printf 'vm_accelerator_mode=%s\n' "$([[ "${PHOTON_VM_FORCE_TCG:-0}" == "1" ]] && echo tcg || echo kvm)"
    printf 'photon_vm_console_wait_timeout=%s\n' "${PHOTON_VM_CONSOLE_WAIT_TIMEOUT:-}"
    printf 'kvm_present=%s\n' "$([[ -e /dev/kvm ]] && echo yes || echo no)"
    printf 'kvm_access=%s\n' "$([[ -r /dev/kvm && -w /dev/kvm ]] && echo rw || echo no)"
    if [[ -e /dev/kvm ]]; then
      printf 'kvm_stat=%s\n' "$(stat -c '%A %U %G %t:%T' /dev/kvm)"
    fi
    if [[ -f /sys/module/kvm_intel/parameters/nested ]]; then
      printf 'kvm_intel_nested=%s\n' "$(cat /sys/module/kvm_intel/parameters/nested)"
    fi
    if [[ -f /sys/module/kvm_amd/parameters/nested ]]; then
      printf 'kvm_amd_nested=%s\n' "$(cat /sys/module/kvm_amd/parameters/nested)"
    fi
    printf 'nix_builders=%s\n' "$(nix config show builders 2>/dev/null | awk -F' = ' 'NR==1 { print $2 }')"
  } >"${LOG_DIR}/environment.txt"
}

finish_environment() {
  local rc="${1:-0}"
  {
    printf 'finished_at=%s\n' "$(date -Is)"
    printf 'exit_status=%s\n' "${rc}"
  } >>"${LOG_DIR}/environment.txt"
}

run_case() {
  local name="$1"
  shift
  local logfile="${LOG_DIR}/${name}.log"
  local metafile="${LOG_DIR}/${name}.meta"
  local started_at ended_at rc

  started_at="$(date -Is)"
  printf 'command=%s\n' "$*" >"${metafile}"
  printf 'started_at=%s\n' "${started_at}" >>"${metafile}"

  log "running ${name}: $*"
  set +e
  (
    cd "${REPO_ROOT}"
    "$@"
  ) 2>&1 | tee "${logfile}"
  rc=${PIPESTATUS[0]}
  set -e

  ended_at="$(date -Is)"
  printf 'ended_at=%s\n' "${ended_at}" >>"${metafile}"
  printf 'exit_code=%s\n' "${rc}" >>"${metafile}"

  if (( rc != 0 )); then
    log "${name} failed; see ${logfile}"
    return "${rc}"
  fi

  log "${name} passed"
}

main() {
  trap 'finish_environment "$?"' EXIT
  prepare_runtime_dirs
  require_publishable_kvm_host
  capture_environment

  run_case fresh-smoke nix run ./nix/test-cluster#cluster -- fresh-smoke
  run_case fresh-demo-vm-webapp nix run ./nix/test-cluster#cluster -- fresh-demo-vm-webapp
  run_case fresh-matrix nix run ./nix/test-cluster#cluster -- fresh-matrix
  run_case chainfire-live-membership-proof nix run ./nix/test-cluster#cluster -- chainfire-live-membership-proof

  log "publishable KVM suite passed; logs in ${LOG_DIR}"
}

main "$@"