#!/bin/sh
set -e

FUELUP_DIR=${FUELUP_DIR-"$HOME/.fuelup"}

main() {
    need_cmd git
    need_cmd curl
    need_cmd chmod
    need_cmd mkdir
    need_cmd rm
    need_cmd rmdir

    check_cargo_bin forc
    check_cargo_bin forc-fmt
    check_cargo_bin forc-lsp
    check_cargo_bin fuel-core

    get_architecture || return 1
    local _arch="$RETVAL"
    assert_nz "$_arch" "arch"

    mkdir -p "$FUELUP_DIR/bin"

    local _fuelup_version
    _published_fuelup_version_url="https://raw.githubusercontent.com/FuelLabs/fuelup/gh-pages/fuelup-version"
    _fuelup_version="$(curl -s $_published_fuelup_version_url)"
    if echo "$_fuelup_version" | grep -q -E '404|400'; then
        warn "fuelup-version was not found on fuelup gh-pages (https://github.com/FuelLabs/fuelup/tree/gh-pages); falling back to using GitHub API."
        _fuelup_version="$(curl -s https://api.github.com/repos/FuelLabs/fuelup/releases/latest | grep "tag_name" | cut -d "\"" -f4 | cut -c 2-)"
    fi

    local _fuelup_url="https://github.com/FuelLabs/fuelup/releases/download/v${_fuelup_version}/fuelup-${_fuelup_version}-${_arch}.tar.gz"

    local _dir
    _dir="$(ensure mktemp -d)"
    local _file="${_dir}/fuelup.tar.gz"

    local _ansi_escapes_are_valid=false
    if [ -t 2 ]; then
        if [ "${TERM+set}" = 'set' ]; then
            case "$TERM" in
                xterm* | rxvt* | urxvt* | linux* | vt*)
                    _ansi_escapes_are_valid=true
                    ;;
            esac
        fi
    fi

    # always prompt PATH modification, unless --no-modify-path provided
    local prompt_modify=yes
    # always install latest toolchain (for convenience), unless --skip-toolchain-installation provided
    local skip_toolchain_installation=no

    for arg in "$@"; do
        case "$arg" in
            --no-modify-path)
                prompt_modify=no
                ;;
            --skip-toolchain-installation)
                skip_toolchain_installation=yes
                ;;
            *)
                OPTIND=1
                if [ "${arg%%--*}" = "" ]; then
                    # Long option (other than --help);
                    # don't attempt to interpret it.
                    continue
                fi
                ;;
        esac
    done

    if [ "$prompt_modify" = "yes" ]; then
        case $SHELL in
            */bash)
                SHELL_PROFILE=$HOME/.bashrc
                ;;
            */zsh)
                SHELL_PROFILE=$HOME/.zshrc
                ;;
            */fish)
                SHELL_PROFILE=$HOME/.config/fish/config.fish
                ;;
            *)
                warn "Failed to detect shell; please add ${FUELUP_DIR}/bin to your PATH manually."
                ;;
        esac

        if [ -n "$SHELL_PROFILE" ]; then
            preinstall_confirmation
            read -r answer </dev/tty
            allow_modify=$(echo "$answer" | cut -c1-1)
            case $allow_modify in
                "y" | "Y")
                    allow_modify=yes
                    printf "\nfuelup will modify your PATH variable for you.\n\n"
                    ;;
                *)
                    allow_modify=no
                    printf "\nfuelup will not modify your PATH variable for you.\n\n"
                    ;;
            esac
        else
            allow_modify=no
        fi
    fi

    if $_ansi_escapes_are_valid; then
        printf "\33[1minfo:\33[0m downloading fuelup %s\n" "$_fuelup_version" 1>&2
    else
        printf 'info: downloading fuelup %s\n' "$_fuelup_version" 1>&2
    fi

    ensure downloader "$_fuelup_url" "$_file" "$_arch"

    ignore tar -xf "$_file" -C "$_dir"

    ensure mv "$_dir/fuelup-${_fuelup_version}-${_arch}/fuelup" "$FUELUP_DIR/bin/fuelup"
    ensure chmod u+x "$FUELUP_DIR/bin/fuelup"

    if [ ! -x "$FUELUP_DIR/bin/fuelup" ]; then
        printf '%s\n' "Cannot execute $FUELUP_DIR/bin/fuelup." 1>&2
        printf '%s\n' "Please copy the file to a location where you can execute binaries and run ./fuelup." 1>&2
        exit 1
    fi

    if [ "$skip_toolchain_installation" = "no" ]; then
        ignore "$FUELUP_DIR/bin/fuelup" "toolchain" "install" "latest"
    fi

    local _retval=$?

    ignore rm "$_file"
    ignore rmdir "$_dir/fuelup-${_fuelup_version}-${_arch}"
    ignore rmdir "$_dir"

    printf '\n'
    printf '%s\n' "fuelup ${_fuelup_version} has been installed in $FUELUP_DIR/bin. To fetch the latest toolchain containing the forc and fuel-core binaries, run 'fuelup toolchain install latest'. To generate completions for your shell, run 'fuelup completions --shell=SHELL'." 1>&2

    if [ "$allow_modify" = "yes" ]; then
        if echo "$PATH" | grep -q "$FUELUP_DIR/bin"; then
            printf "\n%s/bin already exists in your PATH.\n" "$FUELUP_DIR"
        else
            echo "export PATH=\"\$HOME/.fuelup/bin:\$PATH"\" >>"$SHELL_PROFILE"
            printf "\n%s added to PATH. Run 'source %s' or start a new terminal session to use fuelup.\n" "$FUELUP_DIR" "$SHELL_PROFILE"
        fi
    else
        add_path_message
    fi

    return "$_retval"
}

preinstall_confirmation() {
    cat 1>&2 <<EOF

fuelup uses "$FUELUP_DIR" as its home directory to manage the Fuel toolchain, and will install binaries there.

To use the toolchain, you will have to configure your PATH, which tells your machine where to locate fuelup and the Fuel toolchain.

If permitted, fuelup-init will configure your PATH for you by running the following:

    echo "export PATH="\$HOME/.fuelup/bin:\$PATH"" >> $SHELL_PROFILE

Would you like fuelup-init to modify your PATH variable for you? (N/y)
EOF
}

add_path_message() {
    cat 1>&2 <<EOF

You might have to add $FUELUP_DIR/bin to path:

bash/zsh:

export PATH="\${HOME}/.fuelup/bin:\${PATH}"

fish:

fish_add_path ~/.fuelup/bin
EOF
}

get_architecture() {
    local _ostype _cputype
    _ostype="$(uname -s)"
    _cputype="$(uname -m)"

    case "$_ostype" in
        Linux)
            _ostype="unknown-linux-gnu"
            ;;
        Darwin)
            _ostype="apple-darwin"
            ;;
        *)
            err "unsupported os type: $_ostype"
            ;;
    esac

    case "$_cputype" in
        x86_64 | x86-64 | x64 | amd64)
            _cputype="x86_64"
            ;;
        aarch64 | arm64)
            _cputype="aarch64"
            ;;
        *)
            err "unsupported cpu type: $_cputype"
            ;;
    esac

    _arch="${_cputype}-${_ostype}"

    RETVAL="$_arch"
}

check_cargo_bin() {
    if which "${1}" 2>/dev/null | grep -q "[.cargo]"; then
        warn "$1 is already installed via cargo and is in use by your system. You should update your PATH, or execute 'cargo uninstall $1'"
    fi
}

assert_nz() {
    if [ -z "$1" ]; then err "assert_nz $2"; fi
}

say() {
    printf 'fuelup: %s\n' "$1"
}

need_cmd() {
    if ! check_cmd "$1"; then
        err "need '$1' (command not found)"
    fi
}

check_cmd() {
    command -v "$1" >/dev/null 2>&1
}

# Run a command that should never fail. If the command fails execution
# will immediately terminate with an error showing the failing
# command.
ensure() {
    if ! "$@"; then err "command failed: $*"; fi
}

downloader() {
    local _dld
    local _ciphersuites
    local _err
    local _status
    local _retry

    if check_cmd curl; then
        _dld=curl
    elif check_cmd wget; then
        _dld=wget
    else
        _dld='curl or wget' # to be used in error message of need_cmd
    fi

    if [ "$1" = --check ]; then
        need_cmd "$_dld"
    elif [ "$_dld" = curl ]; then
        check_curl_for_retry_support
        _retry="$RETVAL"
        get_ciphersuites_for_curl
        _ciphersuites="$RETVAL"
        if [ -n "$_ciphersuites" ]; then
            # shellcheck disable=SC2086
            _err=$(curl $_retry --proto '=https' --tlsv1.2 --ciphers "$_ciphersuites" --silent --show-error --fail --location "$1" --output "$2" 2>&1)
            _status=$?
        else
            echo "Warning: Not enforcing strong cipher suites for TLS, this is potentially less secure"
            if ! check_help_for "$3" curl --proto --tlsv1.2; then
                echo "Warning: Not enforcing TLS v1.2, this is potentially less secure"
                # shellcheck disable=SC2086
                _err=$(curl $_retry --silent --show-error --fail --location "$1" --output "$2" 2>&1)
                _status=$?
            else
                # shellcheck disable=SC2086
                _err=$(curl $_retry --proto '=https' --tlsv1.2 --silent --show-error --fail --location "$1" --output "$2" 2>&1)
                _status=$?
            fi
        fi
        if [ -n "$_err" ]; then
            echo "$_err" >&2
            if echo "$_err" | grep -q 404; then
                err "fuelup ${_fuelup_version} was not found - either the release is not ready yet or the tag is invalid. You can check if the release is available here: https://github.com/FuelLabs/fuelup/releases/v${_fuelup_version}"
            fi
        fi

        return $_status
    elif [ "$_dld" = wget ]; then
        if [ "$(wget -V 2>&1 | head -2 | tail -1 | cut -f1 -d" ")" = "BusyBox" ]; then
            echo "Warning: using the BusyBox version of wget.  Not enforcing strong cipher suites for TLS or TLS v1.2, this is potentially less secure"
            _err=$(wget "$1" -O "$2" 2>&1)
            _status=$?
        else
            get_ciphersuites_for_wget
            _ciphersuites="$RETVAL"
            if [ -n "$_ciphersuites" ]; then
                _err=$(wget --https-only --secure-protocol=TLSv1_2 --ciphers "$_ciphersuites" "$1" -O "$2" 2>&1)
                _status=$?
            else
                echo "Warning: Not enforcing strong cipher suites for TLS, this is potentially less secure"
                if ! check_help_for "$3" wget --https-only --secure-protocol; then
                    echo "Warning: Not enforcing TLS v1.2, this is potentially less secure"
                    _err=$(wget "$1" -O "$2" 2>&1)
                    _status=$?
                else
                    _err=$(wget --https-only --secure-protocol=TLSv1_2 "$1" -O "$2" 2>&1)
                    _status=$?
                fi
            fi
        fi
        if [ -n "$_err" ]; then
            echo "$_err" >&2
            if echo "$_err" | grep -q ' 404 Not Found$'; then
                err "installer for platform '$3' not found, this may be unsupported"
            fi
        fi
        return $_status
    else
        err "Unknown downloader" # should not reach here
    fi
}

# Check if curl supports the --retry flag, then pass it to the curl invocation.
check_curl_for_retry_support() {
    local _retry_supported=""
    # "unspecified" is for arch, allows for possibility old OS using macports, homebrew, etc.
    if check_help_for "notspecified" "curl" "--retry"; then
        _retry_supported="--retry 3"
    fi

    RETVAL="$_retry_supported"

}

check_help_for() {
    local _arch
    local _cmd
    local _arg
    _arch="$1"
    shift
    _cmd="$1"
    shift

    local _category
    if "$_cmd" --help | grep -q 'For all options use the manual or "--help all".'; then
        _category="all"
    else
        _category=""
    fi

    case "$_arch" in

        *darwin*)
            if check_cmd sw_vers; then
                case $(sw_vers -productVersion) in
                    10.*)
                        # If we're running on macOS, older than 10.13, then we always
                        # fail to find these options to force fallback
                        if [ "$(sw_vers -productVersion | cut -d. -f2)" -lt 13 ]; then
                            # Older than 10.13
                            echo "Warning: Detected macOS platform older than 10.13"
                            return 1
                        fi
                        ;;
                    11.*)
                        # We assume Big Sur will be OK for now
                        ;;
                    *)
                        # Unknown product version, warn and continue
                        echo "Warning: Detected unknown macOS major version: $(sw_vers -productVersion)"
                        echo "Warning: TLS capabilities detection may fail"
                        ;;
                esac
            fi
            ;;

    esac

    for _arg in "$@"; do
        if ! "$_cmd" --help "$_category" | grep -q -- "$_arg"; then
            return 1
        fi
    done

    true # not strictly needed

}

# Return cipher suite string specified by user, otherwise return strong TLS 1.2-1.3 cipher suites
# if support by local tools is detected. Detection currently supports these curl backends:
# GnuTLS and OpenSSL (possibly also LibreSSL and BoringSSL). Return value can be empty.
get_ciphersuites_for_curl() {
    if [ -n "${RUSTUP_TLS_CIPHERSUITES-}" ]; then
        # user specified custom cipher suites, assume they know what they're doing
        RETVAL="$RUSTUP_TLS_CIPHERSUITES"
        return
    fi

    local _openssl_syntax="no"
    local _gnutls_syntax="no"
    local _backend_supported="yes"
    if curl -V | grep -q ' OpenSSL/'; then
        _openssl_syntax="yes"
    elif curl -V | grep -iq ' LibreSSL/'; then
        _openssl_syntax="yes"
    elif curl -V | grep -iq ' BoringSSL/'; then
        _openssl_syntax="yes"
    elif curl -V | grep -iq ' GnuTLS/'; then
        _gnutls_syntax="yes"
    else
        _backend_supported="no"
    fi

    local _args_supported="no"
    if [ "$_backend_supported" = "yes" ]; then
        # "unspecified" is for arch, allows for possibility old OS using macports, homebrew, etc.
        if check_help_for "notspecified" "curl" "--tlsv1.2" "--ciphers" "--proto"; then
            _args_supported="yes"
        fi
    fi

    local _cs=""
    if [ "$_args_supported" = "yes" ]; then
        if [ "$_openssl_syntax" = "yes" ]; then
            _cs=$(get_strong_ciphersuites_for "openssl")
        elif [ "$_gnutls_syntax" = "yes" ]; then
            _cs=$(get_strong_ciphersuites_for "gnutls")
        fi
    fi

    RETVAL="$_cs"
}

# Return strong TLS 1.2-1.3 cipher suites in OpenSSL or GnuTLS syntax. TLS 1.2
# excludes non-ECDHE and non-AEAD cipher suites. DHE is excluded due to bad
# DH params often found on servers (see RFC 7919). Sequence matches or is
# similar to Firefox 68 ESR with weak cipher suites disabled via about:config.
# $1 must be openssl or gnutls.
get_strong_ciphersuites_for() {
    if [ "$1" = "openssl" ]; then
        # OpenSSL is forgiving of unknown values, no problems with TLS 1.3 values on versions that don't support it yet.
        echo "TLS_AES_128_GCM_SHA256:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_256_GCM_SHA384:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384"
    elif [ "$1" = "gnutls" ]; then
        # GnuTLS isn't forgiving of unknown values, so this may require a GnuTLS version that supports TLS 1.3 even if wget doesn't.
        # Begin with SECURE128 (and higher) then remove/add to build cipher suites. Produces same 9 cipher suites as OpenSSL but in slightly different order.
        echo "SECURE128:-VERS-SSL3.0:-VERS-TLS1.0:-VERS-TLS1.1:-VERS-DTLS-ALL:-CIPHER-ALL:-MAC-ALL:-KX-ALL:+AEAD:+ECDHE-ECDSA:+ECDHE-RSA:+AES-128-GCM:+CHACHA20-POLY1305:+AES-256-GCM"
    fi
}

err() {
    say "$1" >&2
    exit 1
}

warn() {
    say "warning: ${1}" >&2
}

# This is just for indicating that commands' results are being
# intentionally ignored. Usually, because it's being executed
# as part of error handling.
ignore() {
    "$@"
}
main "$@" || exit 1
