#!/bin/sh
# shellcheck shell=dash

# A simple script that is run on a remote host to download and install the
# agent binary.

set -u

# For Dev: file:///home/nikos/Projects/prymn/agent/target/debug/prymn_agent
GET_PRYMN_ROOT="${GET_PRYMN_ROOT:?You need to set GET_PRYMN_ROOT to the prymn_agent path for now}"

main() {
    # Check for dependencies
    check_for_command curl
    check_for_command mktemp

    local dir
    if ! dir="$(mktemp -d)"; then
        error "mktemp was not executed successfully"
    fi

    local file="${dir}/prymn_agent"
    local url="${GET_PRYMN_ROOT}"

    printf "downloading prymn agent...\n" 1>&2

    ensure download "${url}" "${file}"
    ensure chmod u+x "$file"

    # Run the installer
    "$file" --install
    local ret=$?

    rm "${file}"
    rmdir "${dir}"

    return $ret
}

download() {
    local err
    err=$(curl -sSfL "$1" -o "$2" 2>&1)
    if [ -n "$err" ]; then
        error "$err"
    fi
}

error() {
    printf "Error: %s\n" "$1" >&2
    exit 1
}

check_for_command() {
    if ! command -v "$1" > /dev/null 2>&1; then
        error "get_prymn.sh requires the program '$1' but it was not found in your system."
    fi
}

ensure() {
    "$@" || error "failed to execute: $*"
}

main "$@" || exit 1