#!/usr/bin/env bash

# shellcheck disable=SC2001

DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"

OS=$(uname)
case "$OS" in
    Linux)
        OS="${OS,,}"
        ;;
    Darwin)
        OS="osx"
        ;;
    *)
        printf 'Unsupported system\n'
        exit 1
        ;;
esac

# get SDK version in the format of EDITIONuVERSIONbBUILD e.g. 11u06b722
function get_sdk_version() {
    sed 's/jbr\?sdk-\?\([[:digit:]]\+\)[u_]\([[:digit:]]\+\)[_-]\?\([[:digit:]]\+\)\(-[[:alpha:]]\+-[xi][[:digit:]]\+-\)\?\(b[[:digit:]]\+\)\..*/\1u\2\3\5/' <<< "$1"
}

function compare_sdk_versions() {
    readarray -d $'\t' L <<< "$(sed "s/^0*\([0-9]\+\)u0*\([0-9]\+\)b0*\([0-9]\+\)$/\1\t\2\t\3/" <<< "$1")"
    readarray -d $'\t' R <<< "$(sed "s/^0*\([0-9]\+\)u0*\([0-9]\+\)b0*\([0-9]\+\)$/\1\t\2\t\3/" <<< "$2")"
    for i in "${!L[@]}"; do
        if [[ "${L[$i]}" -lt "${R[$i]}" ]]; then
            printf -- '-1'
            return 0
        elif [[ "${L[$i]}" -gt "${R[$i]}" ]]; then
            printf '1'
            return 0
        fi
    done
    printf '0'
}

function get_download_link() {
    printf 'https://bintray.com/jetbrains/intellij-jbr/download_file?file_path=%s' "$1"
}

# list local SDKs
readarray -d $'\n' -t SDK_LIST <<< "$(find "$DIR" -maxdepth 1 -type f \( -name "jbrsdk-11*.tar.gz" -or -name "jbrsdk-8*.tar.gz" \) -exec basename '{}' \; | sort)"
printf 'Fetching file list...\n\n'
# list remote SDKs via Bintray API
for sdk_edition in '8' '11'; do
    DOWNLOADABLE_FILES_VAR_NAME="DOWNLOADABLE_FILES_$sdk_edition"
    BINTRAY_API="https://api.bintray.com/packages/jetbrains/intellij-jbr/jbrsdk$sdk_edition-$OS-x64/files"
    readarray -d $'\n' -t "$DOWNLOADABLE_FILES_VAR_NAME" <<< "$(curl $BINTRAY_API 2>/dev/null | jq -r '[.[] | select(.path | contains("sdk") and (contains("checksum") | not))] | sort_by(.created) | reverse | .[].path')"
done

declare -a TO_DOWNLOAD=()
declare -a TO_REMOVE=()

# find latest builds for local SDKs
printf "INSTALLED\t\t\t\tLATEST\n"
for sdk in "${SDK_LIST[@]}"; do
    SDK_VERSION=$(get_sdk_version "$sdk")
    FILE_NAME=""
    sdk_edition="$(cut -d 'u' -f 1 <<< "$SDK_VERSION")"
    DOWNLOADABLE_FILES_VAR_NAME="DOWNLOADABLE_FILES_${sdk_edition}[@]"
    for sdk_remote in "${!DOWNLOADABLE_FILES_VAR_NAME}"; do
        SDK_REMOTE_VERSION=$(get_sdk_version "$sdk_remote")
        if [[ "$SDK_VERSION" == "$SDK_REMOTE_VERSION" ]]; then
            # find out the filename of the latest build in DOWNLOADABLE_FILES_x, which was sorted by creation date descendingly
            FILE_NAME="$sdk_remote"
            break
        fi
    done
    if [[ "$sdk" == "$FILE_NAME" ]]; then
        printf '%s\t(UP-TO-DATE)\n' "$sdk"
    else
        printf '%s\t%s\n' "$sdk" "$FILE_NAME"
        DOWNLOAD_LINK=$(get_download_link "$FILE_NAME")
        TO_DOWNLOAD+=( "$DOWNLOAD_LINK" )
        TO_REMOVE+=( "$sdk" )
    fi
done

# find the latest remote SDK
declare -A LATEST_INSTALLED
declare -A LATEST_AVAILABLE
declare -A LATEST_LINK
for sdk_edition in '8' '11'; do
    for sdk in "${SDK_LIST[@]}"; do
        SDK_VERSION=$(get_sdk_version "$sdk")
        if [[ "$SDK_VERSION" == "$sdk_edition""u"* && ( -z "${LATEST_INSTALLED[$sdk_edition]}" || $(compare_sdk_versions "$SDK_VERSION" "${LATEST_INSTALLED[$sdk_edition]}") -gt 0 ) ]]; then
            LATEST_INSTALLED[$sdk_edition]="$SDK_VERSION"
        fi
    done
    DOWNLOADABLE_FILES_VAR_NAME="DOWNLOADABLE_FILES_${sdk_edition}[@]"
    # we have to traverse through the whole list as new builds of old versions can be released after new versions
    for sdk in "${!DOWNLOADABLE_FILES_VAR_NAME}"; do
        SDK_VERSION=$(get_sdk_version "$sdk")
        if [[ "$SDK_VERSION" == "$sdk_edition""u"* && ( -z "${LATEST_AVAILABLE[$sdk_edition]}" || $(compare_sdk_versions "$SDK_VERSION" "${LATEST_AVAILABLE[$sdk_edition]}") -gt 0 ) ]]; then
            LATEST_AVAILABLE[$sdk_edition]="$SDK_VERSION"
            LATEST_LINK[$sdk_edition]=$(get_download_link "$sdk")
        fi
    done
done

if [[ "${#TO_DOWNLOAD[@]}" -gt 0 ]]; then
    printf '\n'
    read -p "Upgrade all? [y/n] " -n 1 -r
    printf '\n'
    if [[ "$REPLY" != "y" ]]; then
        TO_DOWNLOAD=()
        TO_REMOVE=()
    fi
fi
for sdk_edition in '8' '11'; do
    if [[ -z "${LATEST_INSTALLED[$sdk_edition]}" || $(compare_sdk_versions "${LATEST_INSTALLED[$sdk_edition]}" "${LATEST_AVAILABLE[$sdk_edition]}") -lt 0 ]]; then
        printf '\n'
        read -p "Latest SDK $sdk_edition version ${LATEST_AVAILABLE[$sdk_edition]} is not installed yet. Download? [y/n] " -n 1 -r
        printf '\n'
        if [[ "$REPLY" == "y" ]]; then
            TO_DOWNLOAD+=( "${LATEST_LINK[$sdk_edition]}" )
            TO_REMOVE+=( "" )
        fi
    fi
done

if [[ "${#TO_DOWNLOAD[@]}" -eq 0 ]]; then
    exit 0
fi

for i in "${!TO_DOWNLOAD[@]}"; do
    aria2c -d "$DIR" -s4 -x4 "${TO_DOWNLOAD[$i]}"
    # shellcheck disable=SC2181
    if [[ $? -eq 0 && -n "${TO_REMOVE[$i]}" ]]; then
        # delete old build if download was successful
        rm "$DIR/${TO_REMOVE[$i]}"
    fi
done