# Copyright (c) .NET Foundation and contributors. All rights reserved.
# Licensed under the MIT license. See LICENSE file in the project root for full license information.
#

# Note: This script should be compatible with the dash shell used in Ubuntu. So avoid bashisms! See https://wiki.ubuntu.com/DashAsBinSh for more info

# Stop script on NZEC
set -e
# Stop script if unbound variable found (use ${var:-} if intentional)
set -u
# By default cmd1 | cmd2 returns exit code of cmd2 regardless of cmd1 success
# This is causing it to fail
set -o pipefail

# Use in the the functions: eval $invocation
invocation='say_verbose "Calling: ${yellow:-}${FUNCNAME[0]} ${green:-}$*${normal:-}"'

# standard output may be used as a return value in the functions
# we need a way to write text on the screen in the functions so that
# it won't interfere with the return value.
# Exposing stream 3 as a pipe to standard output of the script itself
exec 3>&1

# Setup some colors to use. These need to work in fairly limited shells, like the Ubuntu Docker container where there are only 8 colors.
# See if stdout is a terminal
if [ -t 1 ]; then
    # see if it supports colors
    ncolors=$(tput colors)
    if [ -n "$ncolors" ] && [ $ncolors -ge 8 ]; then
        bold="$(tput bold)"
        normal="$(tput sgr0)"
        black="$(tput setaf 0)"
        red="$(tput setaf 1)"
        green="$(tput setaf 2)"
        yellow="$(tput setaf 3)"
        blue="$(tput setaf 4)"
        magenta="$(tput setaf 5)"
        cyan="$(tput setaf 6)"
        white="$(tput setaf 7)"
    fi
fi

say_err() {
    printf "%b\n" "${red:-}dotnet_install: Error: $1${normal:-}" >&2
}

say() {
    # using stream 3 (defined in the beginning) to not interfere with stdout of functions
    # which may be used as return value
    printf "%b\n" "${cyan:-}dotnet-install:${normal:-} $1" >&3
}

say_verbose() {
    if [ "$verbose" = true ]; then
        say "$1"
    fi
}

get_current_os_name() {
    eval $invocation

    local uname=$(uname)
    if [ "$uname" = "Darwin" ]; then
        echo "osx"
        return 0
    else
        # Detect Distro
        if [ "$(cat /etc/*-release | grep -cim1 ubuntu)" -eq 1 ]; then
            echo "ubuntu"
            return 0
        elif [ "$(cat /etc/*-release | grep -cim1 centos)" -eq 1 ]; then
            echo "centos"
            return 0
        elif [ "$(cat /etc/*-release | grep -cim1 rhel)" -eq 1 ]; then
            echo "rhel"
            return 0
        elif [ "$(cat /etc/*-release | grep -cim1 debian)" -eq 1 ]; then
            echo "debian"
            return 0
        fi
    fi
    
    say_err "OS name could not be detected"
    return 1
}

machine_has() {
    eval $invocation
    
    which "$1" > /dev/null 2>&1
    return $?
}

check_min_reqs() {
    if ! machine_has "curl"; then
        say_err "curl is required to download dotnet. Install curl to proceed."
        return 1
    fi
    
    return 0
}

check_pre_reqs() {
    eval $invocation
    
    local failing=false;

    if [ "${DOTNET_INSTALL_SKIP_PREREQS:-}" = "1" ]; then
        return 0
    fi

    if [ "$(uname)" = "Linux" ]; then
        if ! [ -x "$(command -v ldconfig)" ]; then
            echo "ldconfig is not in PATH, trying /sbin/ldconfig."
            LDCONFIG_COMMAND="/sbin/ldconfig"
        else
            LDCONFIG_COMMAND="ldconfig"
        fi

        [ -z "$($LDCONFIG_COMMAND -p | grep libunwind)" ] && say_err "Unable to locate libunwind. Install libunwind to continue" && failing=true
        [ -z "$($LDCONFIG_COMMAND -p | grep libssl)" ] && say_err "Unable to locate libssl. Install libssl to continue" && failing=true
        [ -z "$($LDCONFIG_COMMAND -p | grep libcurl)" ] && say_err "Unable to locate libcurl. Install libcurl to continue" && failing=true
        [ -z "$($LDCONFIG_COMMAND -p | grep libicu)" ] && say_err "Unable to locate libicu. Install libicu to continue" && failing=true
        [ -z "$($LDCONFIG_COMMAND -p | grep gettext)" ] && say_err "Unable to locate gettext. Install gettext to continue" && failing=true
    fi

    if [ "$failing" = true ]; then
       return 1
    fi
    
    return 0
}

# args:
# input - $1
to_lowercase() {
    #eval $invocation
    
    echo "$1" | tr '[:upper:]' '[:lower:]'
    return 0
}

# args:
# input - $1
remove_trailing_slash() {
    #eval $invocation
    
    local input=${1:-}
    echo "${input%/}"
    return 0
}

# args:
# input - $1
remove_beginning_slash() {
    #eval $invocation
    
    local input=${1:-}
    echo "${input#/}"
    return 0
}

# args:
# root_path - $1
# child_path - $2 - this parameter can be empty
combine_paths() {
    eval $invocation
    
    # TODO: Consider making it work with any number of paths. For now:
    if [ ! -z "${3:-}" ]; then
        say_err "combine_paths: Function takes two parameters."
        return 1
    fi
    
    local root_path=$(remove_trailing_slash $1)
    local child_path=$(remove_beginning_slash ${2:-})
    say_verbose "combine_paths: root_path=$root_path"
    say_verbose "combine_paths: child_path=$child_path"
    echo "$root_path/$child_path"
    return 0
}

get_machine_architecture() {
    eval $invocation
    
    # Currently the only one supported
    echo "x64"
    return 0
}

# args:
# architecture - $1
get_normalized_architecture_from_architecture() {
    eval $invocation
    
    local architecture=$(to_lowercase $1)
    case $architecture in
        \<auto\>)
            echo "$(get_normalized_architecture_from_architecture $(get_machine_architecture))"
            return 0
            ;;
        amd64|x64)
            echo "x64"
            return 0
            ;;
        x86)
            say_err "Architecture ``x86`` currently not supported"
            return 1
            ;;
    esac
   
    say_err "Architecture ``$architecture`` not supported. If you think this is a bug, please report it at https://github.com/dotnet/cli/issues"
    return 1
}

# version_info is a conceptual two line string representing commit hash and 4-part version
# format:
# Line 1: # commit_hash
# Line 2: # 4-part version

# args:
# version_text - stdin
get_version_from_version_info() {
    eval $invocation
    
    cat | tail -n 1
    return 0
}

# args:
# version_text - stdin
get_commit_hash_from_version_info() {
    eval $invocation
    
    cat | head -n 1
    return 0
}

# args:
# install_root - $1
# relative_path_to_package - $2
# specific_version - $3
is_dotnet_package_installed() {
    eval $invocation
    
    local install_root=$1
    local relative_path_to_package=$2
    local specific_version=$3
    
    local dotnet_package_path=$(combine_paths $(combine_paths $install_root $relative_path_to_package) $specific_version)
    say_verbose "is_dotnet_package_installed: dotnet_package_path=$dotnet_package_path"
    
    if [ -d "$dotnet_package_path" ]; then
        return 0
    else
        return 1
    fi
}

# args:
# azure_feed - $1
# azure_channel - $2
# normalized_architecture - $3
get_latest_version_info() {
    eval $invocation
    
    local azure_feed=$1
    local azure_channel=$2
    local normalized_architecture=$3
    
    local osname=$(get_current_os_name)
    
    local version_file_url="$azure_feed/$azure_channel/dnvm/latest.$osname.$normalized_architecture.version"
    say_verbose "get_latest_version_info: latest url: $version_file_url"
    
    download $version_file_url
    return $?
}

# args:
# channel - $1
get_azure_channel_from_channel() {
    eval $invocation
    
    local channel=$(to_lowercase $1)
    case $channel in
        future|dev)
            echo "dev"
            return 0
            ;;
        preview|beta)
            echo "beta"
            return 0
            ;;
        production)
            say_err "Production channel does not exist yet"
            return 1
    esac
    
    say_err "``$1`` is an invalid channel name. Use one of the following: ``future``, ``preview``, ``production``"
    return 1
}

# args:
# azure_feed - $1
# azure_channel - $2
# normalized_architecture - $3
# version - $4
get_specific_version_from_version() {
    eval $invocation
    
    local azure_feed=$1
    local azure_channel=$2
    local normalized_architecture=$3
    local version=$(to_lowercase $4)
    
    case $version in
        latest)
            local version_info="$(get_latest_version_info $azure_feed $azure_channel $normalized_architecture)"
            say_verbose "get_specific_version_from_version: version_info=$version_info"
            echo "$version_info" | get_version_from_version_info
            return 0
            ;;
        lkg)
            say_err "``--version LKG`` not supported yet."
            return 1
            ;;
        *)
            echo $version
            return 0
            ;;
    esac
}

# args:
# azure_feed - $1
# azure_channel - $2
# normalized_architecture - $3
# specific_version - $4
construct_download_link() {
    eval $invocation
    
    local azure_feed=$1
    local azure_channel=$2
    local normalized_architecture=$3
    local specific_version=$4
    
    local osname=$(get_current_os_name)
    
    local download_link="$azure_feed/$azure_channel/Binaries/$specific_version/dotnet-dev-$osname-$normalized_architecture.$specific_version.tar.gz"
    echo "$download_link"
    return 0
}

get_user_share_path() {
    eval $invocation
    
    if [ ! -z "${DOTNET_INSTALL_DIR:-}" ]; then
        echo $DOTNET_INSTALL_DIR
    else
        echo "/usr/local/share/dotnet"
    fi
    return 0
}

# args:
# install_dir - $1
resolve_installation_path() {
    eval $invocation
    
    local install_dir=$1
    if [ "$install_dir" = "<auto>" ]; then
        local user_share_path=$(get_user_share_path)
        say_verbose "resolve_installation_path: share_path=$user_share_path"
        echo "$user_share_path"
        return 0
    fi
    
    echo "$install_dir"
    return 0
}

# args:
# install_root - $1
get_installed_version_info() {
    eval $invocation
    
    local install_root=$1
    local version_file=$(combine_paths "$install_root" "$local_version_file_relative_path")
    say_verbose "Local version file: $version_file"
    if [ ! -z "$version_file" ] | [ -r "$version_file" ]; then
        local version_info="$(cat $version_file)"
        echo "$version_info"
        return 0
    fi
    
    say_verbose "Local version file not found."
    return 0
}

# args:
# relative_or_absolute_path - $1
get_absolute_path() {
    eval $invocation
    
    local relative_or_absolute_path=$1
    echo $(cd $(dirname "$1") && pwd -P)/$(basename "$1")
    return 0
}

# args:
# input_files - stdin
# root_path - $1
# out_path - $2
# override - $3
copy_files_or_dirs_from_list() {
    eval $invocation

    local root_path=$(remove_trailing_slash $1)
    local out_path=$(remove_trailing_slash $2)
    local override=$3
    local override_switch=$(if [ "$override" = false ]; then printf -- "-n"; fi)
    
    cat | uniq | while read -r file_path; do
        local path=$(remove_beginning_slash ${file_path#$root_path})
        local target=$out_path/$path
        if [ "$override" = true ] || (! ([ -d "$target" ] || [ -e "$target" ])); then
            mkdir -p $out_path/$(dirname $path)
            cp -R $override_switch $root_path/$path $target
        fi
    done
}

# args:
# zip_path - $1
# out_path - $2
extract_dotnet_package() {
    eval $invocation
    
    local zip_path=$1
    local out_path=$2
    
    local temp_out_path=$(mktemp -d $temporary_file_template)
    
    local failed=false
    tar -xzf "$zip_path" -C "$temp_out_path" > /dev/null || failed=true
    
    local folders_with_version_regex='^.*/[0-9]+\.[0-9]+[^/]+/'
    find $temp_out_path -type f | grep -Eo $folders_with_version_regex | copy_files_or_dirs_from_list $temp_out_path $out_path false
    find $temp_out_path -type f | grep -Ev $folders_with_version_regex | copy_files_or_dirs_from_list $temp_out_path $out_path true
    
    rm -rf $temp_out_path
    
    if [ "$failed" = true ]; then
        say_err "Extraction failed"
        return 1
    fi
}

# args:
# remote_path - $1
# [out_path] - $2 - stdout if not provided
download() {
    eval $invocation
    
    local remote_path=$1
    local out_path=${2:-}

    local failed=false
    if [ -z "$out_path" ]; then
        curl --fail -s $remote_path || failed=true
    else
        curl --fail -s -o $out_path $remote_path || failed=true
    fi
    
    if [ "$failed" = true ]; then
        say_err "Download failed"
        return 1
    fi
}

calculate_vars() {
    eval $invocation
    
    azure_channel=$(get_azure_channel_from_channel "$channel")
    say_verbose "azure_channel=$azure_channel"
    
    normalized_architecture=$(get_normalized_architecture_from_architecture "$architecture")
    say_verbose "normalized_architecture=$normalized_architecture"
    
    specific_version=$(get_specific_version_from_version $azure_feed $azure_channel $normalized_architecture $version)
    say_verbose "specific_version=$specific_version"
    if [ -z "$specific_version" ]; then
        say_err "Could not get version information."
        return 1
    fi
    
    download_link=$(construct_download_link $azure_feed $azure_channel $normalized_architecture $specific_version)
    say_verbose "download_link=$download_link"
    
    install_root=$(resolve_installation_path $install_dir)
    say_verbose "install_root=$install_root"
}

install_dotnet() {
    eval $invocation
    
    if is_dotnet_package_installed $install_root "sdk" $specific_version; then
        say ".NET SDK version $specific_version is already installed."
        return 0
    fi
    
    mkdir -p $install_root
    zip_path=$(mktemp $temporary_file_template)
    say_verbose "Zip path: $zip_path"
    
    say "Downloading $download_link"
    download "$download_link" $zip_path
    say_verbose "Downloaded file exists and readable? $(if [ -r $zip_path ]; then echo "yes"; else echo "no"; fi)"
    
    say "Extracting zip"
    extract_dotnet_package $zip_path $install_root
    
    return 0
}

local_version_file_relative_path="/.version"
bin_folder_relative_path=""
temporary_file_template="${TMPDIR:-/tmp}/dotnet.XXXXXXXXX"

channel="preview"
version="Latest"
install_dir="<auto>"
architecture="<auto>"
debug_symbols=false
dry_run=false
no_path=false
azure_feed="https://dotnetcli.blob.core.windows.net/dotnet"
verbose=false

while [ $# -ne 0 ]
do
    name=$1
    case $name in
        -c|--channel|-[Cc]hannel)
            shift
            channel=$1
            ;;
        -v|--version|-[Vv]ersion)
            shift
            version="$1"
            ;;
        -i|--install-dir|-[Ii]nstall[Dd]ir)
            shift
            install_dir="$1"
            ;;
        --arch|--architecture|-[Aa]rch|-[Aa]rchitecture)
            shift
            architecture="$1"
            ;;
        --debug-symbols|-[Dd]ebug[Ss]ymbols)
            debug_symbols=true
            ;;
        --dry-run|-[Dd]ry[Rr]un)
            dry_run=true
            ;;
        --no-path|-[Nn]o[Pp]ath)
            no_path=true
            ;;
        --verbose|-[Vv]erbose)
            verbose=true
            ;;
        --azure-feed|-[Aa]zure[Ff]eed)
            shift
            azure_feed="$1"
            ;;
        -?|--?|-h|--help|-[Hh]elp)
            script_name="$(basename $0)"
            echo ".NET Tools Installer"
            echo "Usage: $script_name [-c|--channel <CHANNEL>] [-v|--version <VERSION>] [-p|--prefix <DESTINATION>]"
            echo "       $script_name -h|-?|--help"
            echo ""
            echo "$script_name is a simple command line interface for obtaining dotnet cli."
            echo ""
            echo "Options:"
            echo "  -c,--channel <CHANNEL>         Download from the CHANNEL specified (default: $channel)."
            echo "      -Channel"
            echo "  -v,--version <VERSION>         Use specific version, ``latest`` or ``lkg``. Defaults to ``latest``."
            echo "      -Version"
            echo "  -i,--install-dir <DIR>         Install under specified location (see Install Location below)"
            echo "      -InstallDir"
            echo "  --architecture <ARCHITECTURE>  Architecture of .NET Tools. Currently only x64 is supported."
            echo "      --arch,-Architecture,-Arch"
            echo "  --debug-symbols,-DebugSymbols  Specifies if symbols should be included in the installation."
            echo "  --dry-run,-DryRun              Do not perform installation. Display download link."
            echo "  --no-path, -NoPath             Do not set PATH for the current process."
            echo "  --verbose,-Verbose             Display diagnostics information."
            echo "  --azure-feed,-AzureFeed        Azure feed location. Defaults to $azure_feed"
            echo "  -?,--?,-h,--help,-Help         Shows this help message"
            echo ""
            echo "Install Location:"
            echo "  Location is chosen in following order:"
            echo "    - --install-dir option"
            echo "    - Environmental variable DOTNET_INSTALL_DIR"
            echo "    - /usr/local/share/dotnet"
            exit 0
            ;;
        *)
            say_err "Unknown argument \`$name\`"
            exit 1
            ;;
    esac

    shift
done

check_min_reqs
calculate_vars
if [ "$dry_run" = true ]; then
    say "Payload URL: $download_link"
    say "Repeatable invocation: ./$(basename $0) --version $specific_version --channel $channel --install-dir $install_dir"
    return 0
fi

check_pre_reqs
install_dotnet

bin_path=$(get_absolute_path $(combine_paths $install_root $bin_folder_relative_path))
if [ "$no_path" = false ]; then
    say "Adding to current process PATH: ``$bin_path``. Note: This change will be visible only when sourcing script."
    export PATH=$PATH:$bin_path
else
    say "Binaries of dotnet can be found in $bin_path"
fi

say "Installation finished successfuly."