#!/bin/bash

ynh_go_try_bash_extension() {
  if [ -x src/configure ]; then
    src/configure && make -C src || {
      ynh_print_info --message="Optional bash extension failed to build, but things will still work normally."
    }
  fi
}

goenv_install_dir="/opt/goenv"
go_version_path="$goenv_install_dir/versions"
# goenv_ROOT is the directory of goenv, it needs to be loaded as a environment variable.
export GOENV_ROOT="$goenv_install_dir"

# Load the version of Go for an app, and set variables.
#
# ynh_use_go has to be used in any app scripts before using Go for the first time.
# This helper will provide alias and variables to use in your scripts.
#
# To use gem or Go, use the alias `ynh_gem` and `ynh_go`
# Those alias will use the correct version installed for the app
# For example: use `ynh_gem install` instead of `gem install`
#
# With `sudo` or `ynh_exec_as`, use instead the fallback variables `$ynh_gem` and `$ynh_go`
# And propagate $PATH to sudo with $ynh_go_load_path
# Exemple: `ynh_exec_as $app $ynh_go_load_path $ynh_gem install`
#
# $PATH contains the path of the requested version of Go.
# However, $PATH is duplicated into $go_path to outlast any manipulation of $PATH
# You can use the variable `$ynh_go_load_path` to quickly load your Go version
#  in $PATH for an usage into a separate script.
# Exemple: $ynh_go_load_path $install_dir/script_that_use_gem.sh`
#
#
# Finally, to start a Go service with the correct version, 2 solutions
#  Either the app is dependent of Go or gem, but does not called it directly.
#  In such situation, you need to load PATH
#    `Environment="__YNH_GO_LOAD_PATH__"`
#    `ExecStart=__INSTALL_DIR__/my_app`
#     You will replace __YNH_GO_LOAD_PATH__ with $ynh_go_load_path
#
#  Or Go start the app directly, then you don't need to load the PATH variable
#    `ExecStart=__YNH_GO__ my_app run`
#     You will replace __YNH_GO__ with $ynh_go
#
#
# one other variable is also available
#   - $go_path: The absolute path to Go binaries for the chosen version.
#
# usage: ynh_use_go
#
# Requires YunoHost version 3.2.2 or higher.
ynh_use_go () {
    go_version=$(ynh_app_setting_get --app=$app --key=go_version)

    # Get the absolute path of this version of Go
    go_path="$go_version_path/$go_version/bin"

    # Allow alias to be used into bash script
    shopt -s expand_aliases

    # Create an alias for the specific version of Go and a variable as fallback
    ynh_go="$go_path/go"
    alias ynh_go="$ynh_go"

    # Load the path of this version of Go in $PATH
    if [[ :$PATH: != *":$go_path"* ]]; then
        PATH="$go_path:$PATH"
    fi
    # Create an alias to easily load the PATH
    ynh_go_load_path="PATH=$PATH"

    # Sets the local application-specific Go version
    pushd $install_dir
        $goenv_install_dir/bin/goenv local $go_version
    popd
}

# Install a specific version of Go
#
# ynh_install_go will install the version of Go provided as argument by using goenv.
#
# This helper creates a /etc/profile.d/goenv.sh that configures PATH environment for goenv
# for every LOGIN user, hence your user must have a defined shell (as opposed to /usr/sbin/nologin)
#
# Don't forget to execute go-dependent command in a login environment
# (e.g. sudo --login option)
# When not possible (e.g. in systemd service definition), please use direct path
# to goenv shims (e.g. $goenv_ROOT/shims/bundle)
#
# usage: ynh_install_go --go_version=go_version
# | arg: -v, --go_version= - Version of go to install.
#
# Requires YunoHost version 3.2.2 or higher.
ynh_install_go () {
    # Declare an array to define the options of this helper.
    local legacy_args=v
    local -A args_array=( [v]=go_version= )
    local go_version
    # Manage arguments with getopts
    ynh_handle_getopts_args "$@"

    # Load goenv path in PATH
    local CLEAR_PATH="$goenv_install_dir/bin:$PATH"

    # Remove /usr/local/bin in PATH in case of Go prior installation
    PATH=$(echo $CLEAR_PATH | sed 's@/usr/local/bin:@@')

    # Move an existing Go binary, to avoid to block goenv
    test -x /usr/bin/go && mv /usr/bin/go /usr/bin/go_goenv

    # Install or update goenv
    goenv="$(command -v goenv $goenv_install_dir/bin/goenv | head -1)"
    if [ -n "$goenv" ]; then
        ynh_print_info --message="goenv already seems installed in \`$goenv'."
        pushd "${goenv%/*/*}"
            if git remote -v 2>/dev/null | grep "https://github.com/syndbg/goenv.git"; then
                echo "Trying to update with git..."
                git pull -q --tags origin master
                cd ..
                ynh_go_try_bash_extension
            fi
        popd
    else
        ynh_print_info --message="Installing goenv with git..."
        mkdir -p $goenv_install_dir
        pushd $goenv_install_dir
            git init -q
            git remote add -f -t master origin https://github.com/syndbg/goenv.git > /dev/null 2>&1
            git checkout -q -b master origin/master
            ynh_go_try_bash_extension
            goenv=$goenv_install_dir/bin/goenv
        popd
    fi

    goenv_latest="$(command -v "$goenv_install_dir"/plugins/*/bin/goenv-latest goenv-latest | head -1)"
    if [ -n "$goenv_latest" ]; then
        ynh_print_info --message="\`goenv latest' command already available in \`$goenv_latest'."
        pushd "${goenv_latest%/*/*}"
            if git remote -v 2>/dev/null | grep "https://github.com/momo-lab/xxenv-latest.git"; then
                ynh_print_info --message="Trying to update xxenv-latest with git..."
                git pull -q origin master
            fi
        popd
    else
        ynh_print_info --message="Installing xxenv-latest with git..."
        mkdir -p "${goenv_install_dir}/plugins"
        git clone -q https://github.com/momo-lab/xxenv-latest.git "${goenv_install_dir}/plugins/xxenv-latest"
    fi

    # Enable caching
    mkdir -p "${goenv_install_dir}/cache"

    # Create shims directory if needed
    mkdir -p "${goenv_install_dir}/shims"

    # Restore /usr/local/bin in PATH
    PATH=$CLEAR_PATH

    # And replace the old Go binary
    test -x /usr/bin/go_goenv && mv /usr/bin/go_goenv /usr/bin/go

    # Install the requested version of Go
    local final_go_version=$(goenv latest --print $go_version)
    ynh_print_info --message="Installation of Go-$final_go_version"
    goenv install --skip-existing $final_go_version

    # Store go_version into the config of this app
    ynh_app_setting_set --app=$YNH_APP_INSTANCE_NAME --key=go_version --value=$final_go_version

    # Cleanup Go versions
    ynh_cleanup_go

    # Set environment for Go users
    echo  "#goenv
export GOENV_ROOT=$goenv_install_dir
export PATH=\"$goenv_install_dir/bin:$PATH\"
eval \"\$(goenv init -)\"
#goenv" > /etc/profile.d/goenv.sh

    # Load the environment
    eval "$(goenv init -)"
}

# Remove the version of Go used by the app.
#
# This helper will also cleanup Go versions
#
# usage: ynh_remove_go
ynh_remove_go () {
    local go_version=$(ynh_app_setting_get --app=$YNH_APP_INSTANCE_NAME --key=go_version)

    # Load goenv path in PATH
    local CLEAR_PATH="$goenv_install_dir/bin:$PATH"

    # Remove /usr/local/bin in PATH in case of Go prior installation
    PATH=$(echo $CLEAR_PATH | sed 's@/usr/local/bin:@@')

    # Remove the line for this app
    ynh_app_setting_delete --app=$YNH_APP_INSTANCE_NAME --key=go_version

    # Cleanup Go versions
    ynh_cleanup_go
}

# Remove no more needed versions of Go used by the app.
#
# This helper will check what Go version are no more required,
# and uninstall them
# If no app uses Go, goenv will be also removed.
#
# usage: ynh_cleanup_go
ynh_cleanup_go () {

    # List required Go versions
    local installed_apps=$(yunohost app list | grep -oP 'id: \K.*$')
    local required_go_versions=""
    for installed_app in $installed_apps
    do
        local installed_app_go_version=$(ynh_app_setting_get --app=$installed_app --key="go_version")
        if [[ $installed_app_go_version ]]
        then
            required_go_versions="${installed_app_go_version}\n${required_go_versions}"
        fi
    done
    
    # Remove no more needed Go versions
    local installed_go_versions=$(goenv versions --bare --skip-aliases | grep -Ev '/')
    for installed_go_version in $installed_go_versions
    do
        if ! `echo ${required_go_versions} | grep "${installed_go_version}" 1>/dev/null 2>&1`
        then
            ynh_print_info --message="Removing of Go-$installed_go_version"
            $goenv_install_dir/bin/goenv uninstall --force $installed_go_version
        fi
    done

    # If none Go version is required
    if [[ ! $required_go_versions ]]
    then
        # Remove goenv environment configuration
        ynh_print_info --message="Removing of goenv"
        ynh_secure_remove --file="$goenv_install_dir"
        ynh_secure_remove --file="/etc/profile.d/goenv.sh"
    fi
}