#!/usr/bin/env bash

set -Eeuo pipefail

repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
cd "${repo_root}"

required_tools=(
  bash
  curl
  find
  git
  grep
  helm
  jq
  kubectl
  make
  mc
  openssl
  rg
  sed
)

optional_tools=(
  age
  argocd
  conftest
  flux
  gitleaks
  kubeconform
  shellcheck
  sops
  terraform
  tofu
  trivy
  yamllint
)

activated_tools=()
missing=0

collect_source_files() {
  if git rev-parse --is-inside-work-tree >/dev/null 2>&1; then
    git ls-files --cached --others --exclude-standard -z
  else
    find . \
      \( \
      -type d \
      \( \
      -name .build -o \
      -name .cache -o \
      -name .git -o \
      -name .terraform -o \
      -name .terragrunt-cache -o \
      -name dist -o \
      -name rendered -o \
      -name tmp \
      \) -prune \
      \) -o \
      -type f -print0
  fi
}

source_files=()
while IFS= read -r -d '' file; do
  file="${file#./}"
  if [[ -f "${file}" ]]; then
    source_files+=("${file}")
  fi
done < <(collect_source_files)

has_chart=0
iac_file=""
for file in "${source_files[@]}"; do
  if [[ "${file##*/}" == "Chart.yaml" ]]; then
    has_chart=1
  fi

  case "${file}" in
    bootstrap/*.tf | bootstrap/*.tf.json | bootstrap/*.tofu | bootstrap/*.tofu.json | \
      infrastructure/*.tf | infrastructure/*.tf.json | infrastructure/*.tofu | \
      infrastructure/*.tofu.json)
      iac_file="${file}"
      ;;
  esac
done

if ((has_chart == 1)); then
  activated_tools+=("helm")
fi

if [[ -n "${iac_file}" ]]; then
  iac_engine=""
  if [[ -f infrastructure/.iac-engine && ! -L infrastructure/.iac-engine ]]; then
    iac_engine_values=()
    while IFS= read -r line; do
      case "${line}" in
        "" | \#*)
          continue
          ;;
      esac
      iac_engine_values+=("${line}")
    done <infrastructure/.iac-engine

    if ((${#iac_engine_values[@]} == 1)); then
      iac_engine="${iac_engine_values[0]}"
    fi
  fi

  case "${iac_engine}" in
    terraform | tofu)
      activated_tools+=("${iac_engine}")
      ;;
    *)
      printf '[missing] infrastructure/.iac-engine must select terraform or tofu because IaC files exist.\n' >&2
      missing=1
      ;;
  esac
fi

is_activated() {
  local candidate="$1"
  local tool

  for tool in "${activated_tools[@]}"; do
    if [[ "${candidate}" == "${tool}" ]]; then
      return 0
    fi
  done
  return 1
}

printf 'Required tools\n'
for tool in "${required_tools[@]}"; do
  if command -v "${tool}" >/dev/null 2>&1; then
    printf '  [ok]      %-14s %s\n' "${tool}" "$(command -v "${tool}")"
  else
    printf '  [missing] %s\n' "${tool}"
    missing=1
  fi
done

if ((${#activated_tools[@]} > 0)); then
  printf '\nTools required by activated source files\n'
  for tool in "${activated_tools[@]}"; do
    if command -v "${tool}" >/dev/null 2>&1; then
      printf '  [ok]      %-14s %s\n' "${tool}" "$(command -v "${tool}")"
    else
      printf '  [missing] %s\n' "${tool}"
      missing=1
    fi
  done
fi

printf '\nOptional tools (required only after the related feature is enabled)\n'
for tool in "${optional_tools[@]}"; do
  if is_activated "${tool}"; then
    continue
  fi

  if command -v "${tool}" >/dev/null 2>&1; then
    printf '  [found]   %-14s %s\n' "${tool}" "$(command -v "${tool}")"
  else
    printf '  [not set] %s\n' "${tool}"
  fi
done

if git rev-parse --is-inside-work-tree >/dev/null 2>&1; then
  printf '\nRepository: Git work tree detected.\n'
else
  printf '\nRepository: Git is not initialized yet; run git init when this skeleton becomes a repository.\n'
fi

if ((missing != 0)); then
  printf '\nInstall/configure the missing required items before deployment.\n' >&2
  exit 1
fi

printf '\nDoctor check passed.\n'