#!/bin/sh

#
# Copyright 2000-2026 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
#

# Possible environment variables:
#   KOTLIN_CLI_DOWNLOAD_ROOT        Maven repository to download the Kotlin CLI dist from.
#                                     default: https://packages.jetbrains.team/maven/p/amper/amper
#   KOTLIN_CLI_JRE_DOWNLOAD_ROOT    Url prefix to download the JRE to run the Kotlin CLI
#                                     default: https:/
#   KOTLIN_CLI_BOOTSTRAP_CACHE_DIR  Cache directory to store the extracted JRE and Kotlin CLI distribution
#   KOTLIN_CLI_JAVA_HOME            JRE to run the Kotlin CLI itself (optional, does not affect compilation)
#   KOTLIN_CLI_JAVA_OPTIONS         JVM options to pass to the JVM running the Kotlin CLI (does not affect the user's application)
#   KOTLIN_CLI_NO_WELCOME_BANNER    Disables the first-run welcome message if set to a non-empty value

set -e -u

# The version of the Kotlin Toolchain (and CLI) distribution to provision and use
kotlin_cli_version=0.13.0-dev-4444
# Establish chain of trust from here by specifying exact checksum of Kotlin Toolchain (and CLI) distribution to be run
kotlin_cli_sha256=13c2448146ac6dba0fa3a4e5d367dab73d8cfd7400bab348bebe905c165adecf

KOTLIN_CLI_DOWNLOAD_ROOT="${KOTLIN_CLI_DOWNLOAD_ROOT:-https://packages.jetbrains.team/maven/p/amper/amper}"

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

# usage: check_sha SOURCE_MONIKER FILE SHA_CHECKSUM SHA_SIZE
# $1 SOURCE_MONIKER (e.g. url)
# $2 FILE
# $3 SHA hex string
# $4 SHA size in bits (256, 512, ...)
check_sha() {
  sha_size=$4
  if command -v shasum >/dev/null 2>&1; then
    echo "$3 *$2" | shasum -a "$sha_size" --status -c || {
      die "ERROR: Checksum mismatch for $2 (downloaded from $1): expected checksum $3 but got $(shasum --binary -a "$sha_size" "$2" | awk '{print $1}')"
    }
    return 0
  fi

  shaNsumCommand="sha${sha_size}sum"
  if command -v "$shaNsumCommand" >/dev/null 2>&1; then
    # discard the output as sha*sum may print redundant warnings in some versions
    echo "$3 *$2" | $shaNsumCommand -w -c >/dev/null 2>&1 || {
      die "ERROR: Checksum mismatch for $2 (downloaded from $1): expected checksum $3 but got $($shaNsumCommand "$2" | awk '{print $1}')"
    }
    return 0
  fi

  echo "Both 'shasum' and 'sha${sha_size}sum' utilities are missing. Please install one of them"
  return 1
}


download_and_extract() {
  moniker="$1"
  file_url="$2"
  file_sha="$3"
  sha_size="$4"
  cache_dir="$5"
  extract_dir="$6"
  show_banner_on_cache_miss="$7"

  if [ -e "$extract_dir/.flag" ] && [ "$(cat "$extract_dir/.flag")" = "${file_sha}" ]; then
    # Everything is up-to-date in $extract_dir, do nothing
    return 0;
  fi

  mkdir -p "$cache_dir"

  # Take a lock for the download of this file
  short_sha=$(echo "$file_sha" | cut -c1-32) # cannot use the ${short_sha:0:32} syntax in regular /bin/sh
  download_lock_file="$cache_dir/download-${short_sha}.lock"
  process_lock_file="$cache_dir/download-${short_sha}.$$.lock"
  echo $$ >"$process_lock_file"
  while ! ln "$process_lock_file" "$download_lock_file" 2>/dev/null; do
    lock_owner=$(cat "$download_lock_file" 2>/dev/null || true)
    # We use `kill -0` instead of `ps -p` as the first one is more portable
    if [ -n "$lock_owner" ] && kill -0 "$lock_owner" >/dev/null; then
      echo "Another Kotlin CLI instance (pid $lock_owner) is downloading $moniker. Awaiting the result..."
      sleep 1
    elif [ -n "$lock_owner" ] && [ "$(cat "$download_lock_file" 2>/dev/null)" = "$lock_owner" ]; then
      rm -f "$download_lock_file"
      # We don't want to simply loop again here, because multiple concurrent processes may face this at the same time,
      # which means the 'rm' command above from another script could delete our new valid lock file. Instead, we just
      # ask the user to try again. This doesn't 100% eliminate the race, but the probability of issues is drastically
      # reduced because it would involve 4 processes with perfect timing. We can revisit this later.
      die "Another Kotlin CLI instance (pid $lock_owner) locked the download of $moniker, but is no longer running. The lock file is now removed, please try again."
    fi
  done

  # shellcheck disable=SC2064
  trap "rm -f \"$download_lock_file\"" EXIT
  rm -f "$process_lock_file"

  unlock_and_cleanup() {
    rm -f "$download_lock_file"
    trap - EXIT
    return 0
  }

  if [ -e "$extract_dir/.flag" ] && [ "$(cat "$extract_dir/.flag")" = "${file_sha}" ]; then
    # Everything is up-to-date in $extract_dir, just release the lock
    unlock_and_cleanup
    return 0;
  fi

  if [ "$show_banner_on_cache_miss" = "true" ] && [ -z "${KOTLIN_CLI_NO_WELCOME_BANNER:-}" ]; then
      echo
      cat <<EOF
Welcome to

@@@        @@@@                               @@@    @@@
@@@      @@@@                       @@@       @@@    @@@
@@@    #@@@"                       ,@@@       @@@
@@@  ,@@@%         ,@@@@@@@,     @@@@@@@@@@   @@@    @@@    @@@  ,@@@@@,
@@@ @@@@         @@@@@%"%@@@@@   @@@@@@@@@@   @@@    @@@    @@@@@@%%@@@@@
@@@@@@%         @@@%       %@@@     @@@       @@@    @@@    @@@@      %@@%
@@@ @@@@=      #@@@         @@@#    @@@       @@@    @@@    @@@        @@@
@@@   @@@@     #@@@         @@@#    @@@       @@@    @@@    @@@        @@@
@@@    *@@@%    @@@@       @@@@     @@@       @@@    @@@    @@@        @@@
@@@      %@@@=   %@@@@*,*@@@@%      @@@@###   @@@    @@@    @@@        @@@
@@@        @@@@    "@@@@@@@"         %@@@@@   @@@    @@@    @@@        @@@
EOF
      echo
      echo "This is the first run of the Kotlin CLI v$kotlin_cli_version, so we need to download the Kotlin Toolchain."
      echo "Please give us a few seconds, subsequent runs will be faster."
      echo
  fi

  echo "Downloading $moniker..."

  temp_file="$cache_dir/download-file-$$.bin"
  rm -f "$temp_file"
  if command -v curl >/dev/null 2>&1; then
    if [ -t 1 ]; then CURL_PROGRESS="--progress-bar"; else CURL_PROGRESS="--silent --show-error"; fi
    # shellcheck disable=SC2086
    curl $CURL_PROGRESS -L --fail --retry 5 --connect-timeout 30 --output "${temp_file}" "$file_url"
  elif command -v wget >/dev/null 2>&1; then
    if [ -t 1 ]; then WGET_PROGRESS=""; else WGET_PROGRESS="-nv"; fi
    wget $WGET_PROGRESS --tries=5 --connect-timeout=30 --read-timeout=120 -O "${temp_file}" "$file_url"
  else
    die "ERROR: Please install 'wget' or 'curl', as one of them is required to download $moniker"
  fi

  check_sha "$file_url" "$temp_file" "$file_sha" "$sha_size"

  rm -rf "$extract_dir"
  mkdir -p "$extract_dir"

  case "$file_url" in
    *".zip")
      if command -v unzip >/dev/null 2>&1; then
        unzip -q "$temp_file" -d "$extract_dir"
      else
        die "ERROR: Please install 'unzip', which is required to extract $moniker"
      fi ;;
    *)
      if command -v tar >/dev/null 2>&1; then
        tar -x -f "$temp_file" -C "$extract_dir"
      else
        die "ERROR: Please install 'tar', which is required to extract $moniker"
      fi ;;
  esac

  rm -f "$temp_file"

  echo "$file_sha" >"$extract_dir/.flag"

  # Unlock and cleanup the lock file
  unlock_and_cleanup

  echo "Download complete."
  echo
}


# ********** Project-local version detection **********

# 1. Search upwards for an executable `amper` file and/or `project.yaml`
# Sets wrapper_script to the found wrapper path, or empty string if not found.
find_project_context() {
  wrapper_script=""
  this_script="$(realpath "$0")"
  project_dir=$(pwd)
  while [ "$project_dir" != "/" ] && [ -n "$project_dir" ]; do
    wrapper_candidate="$project_dir/kotlin"
    if [ "$this_script" = "$wrapper_candidate" ]; then
      # Found itself (local wrapper case), no need to update any version or search further.
      return 1
    fi

    if [ -f "$wrapper_candidate" ] && [ -x "$wrapper_candidate" ]; then
      # Found the wrapper — check that a project context exists alongside it
      if [ -f "$project_dir/project.yaml" ] || [ -f "$project_dir/module.yaml" ]; then
        wrapper_script="$wrapper_candidate"
        return 0
      else
        echo "WARNING: Found wrapper script '$wrapper_candidate', but no project.yaml or module.yaml near it. Skipping." >&2
        # Continue the search
      fi
    elif [ -f "$project_dir/project.yaml" ]; then
      # Found project.yaml but no executable wrapper alongside it
      echo "WARNING: Found a project.yaml in '$project_dir', but the wrapper script is missing; using Kotlin Toolchain v$kotlin_cli_version." >&2
      return 1
    fi

    project_dir=$(dirname "$project_dir")
  done
  # Do not check root '/' - it's an unlikely candidate for a project

  return 1
}

parse_project_context() {
  # Parse kotlin_cli_version and kotlin_cli_sha256 from "$wrapper_script" without executing it.
  parsed_kotlin_cli_version=$(
    sed -n 's/^kotlin_cli_version=\([A-Za-z0-9._+-]\{1,\}\)[[:space:]]*$/\1/p' "$wrapper_script" \
      | head -n 1
  )
  parsed_kotlin_cli_sha256=$(
    sed -n 's/^kotlin_cli_sha256=\([0-9a-fA-F]\{64\}\)[[:space:]]*$/\1/p' "$wrapper_script" \
      | head -n 1
  )

  if [ -z "$parsed_kotlin_cli_version" ]; then
    echo "ERROR: Suspicious local wrapper script: failed to detect the distribution version in '$wrapper_script'" >&2
    return 1
  fi
  if [ -z "$parsed_kotlin_cli_sha256" ]; then
    echo "ERROR: Suspicious local wrapper script: failed to detect the distribution checksum in '$wrapper_script'" >&2
    return 1
  fi

  # overwrite builtin values and proceed
  kotlin_cli_version=$parsed_kotlin_cli_version
  kotlin_cli_sha256=$parsed_kotlin_cli_sha256
  return 0
}

if [ -z "${KOTLIN_CLI_WRAPPER_ALWAYS_USE_INTRINSIC_VERSION:-}" ]; then
  find_project_context && parse_project_context
fi

# ********** System detection **********

kernelName=$(uname -s)
case "$kernelName" in
  Darwin* )
    default_kotlin_cli_cache_dir="$HOME/Library/Caches/JetBrains/Kotlin/cli"
    ;;
  Linux* )
    default_kotlin_cli_cache_dir="$HOME/.cache/JetBrains/Kotlin/cli"
    ;;
  CYGWIN* | MSYS* | MINGW* )
    if command -v cygpath >/dev/null 2>&1; then
      default_kotlin_cli_cache_dir=$(cygpath -u "$LOCALAPPDATA\JetBrains\Kotlin\cli")
    else
      die "The 'cypath' command is not available, but the Kotlin CLI needs it. Use kotlin.bat instead, or try a Cygwin or MSYS environment."
    fi
    ;;
  *)
    die "Unsupported platform $kernelName"
    ;;
esac

kotlin_cli_cache_dir="${KOTLIN_CLI_BOOTSTRAP_CACHE_DIR:-$default_kotlin_cli_cache_dir}"

# ********** Provision the Kotlin Toolchain distribution **********

kotlin_cli_url="$KOTLIN_CLI_DOWNLOAD_ROOT/org/jetbrains/kotlin/kotlin-cli/$kotlin_cli_version/kotlin-cli-$kotlin_cli_version-dist.tgz"
kotlin_cli_target_dir="$kotlin_cli_cache_dir/kotlin-cli-$kotlin_cli_version"
download_and_extract "Kotlin Toolchain distribution v$kotlin_cli_version" "$kotlin_cli_url" "$kotlin_cli_sha256" 256 "$kotlin_cli_cache_dir" "$kotlin_cli_target_dir" "true"

# ********** Launch the Kotlin CLI **********

launcher_script="$kotlin_cli_target_dir/bin/launcher.sh"

KOTLIN_CLI_WRAPPER_PATH="$(realpath "$0")" \
exec /bin/sh "$launcher_script" "$@"