#!/bin/sh
set -e

install_dir="/usr/local/bin"
add_alias=0
nightly=0
verify=0
local=0

while true; do
    case "${1}" in
    -a | --alias)
        add_alias=1
        shift 1
        ;;
    -n | --nightly)
        nightly=1
        shift 1
        ;;
    -p | --prefix)
        install_dir=/$2
        shift 2
        ;;
    -V | --verify)
        verify=1
        shift 1
        ;;
    -l | --local)
        local=1
        shift 1
        ;;
    --)
        shift 1
        break
        ;;
    *) break ;;
    esac
done

# prompt for nightly build option if interactive
if [ "$nightly" -eq 0 ] && [ -t 0 ]; then
    printf "do you want to install a Nightly build? [y/N]: "
    read -r answer_nightly
    if [ "$answer_nightly" = "y" ] || [ "$answer_nightly" = "Y" ]; then
        nightly=1
    fi
fi

if [ "$nightly" -eq 1 ]; then
    repo="neurocyte/flow-nightly"
else
    repo="neurocyte/flow"
fi

# detect os and architecture
os="$(uname -s | tr '[:upper:]' '[:lower:]')"
if [ "$os" = "darwin" ]; then
    os="macos"
fi

arch="$(uname -m)"
case "$arch" in
x86_64) arch="x86_64" ;;
arm64) arch="aarch64" ;;
i686) arch="x86" ;;
i386) arch="x86" ;;
esac

# get latest version tag from github releases api
version=$(curl -s "https://api.github.com/repos/$repo/releases/latest" | grep '"tag_name":' | cut -d'"' -f4)
[ -z "$version" ] && {
    echo "failed to fetch latest version"
    exit 1
}

# construct download url
# note: nightly assets are named like "flow-<version>-<os>-<arch>.<ext>"
filename="flow-$version-$os-$arch"
ext="tar.gz"
if [ "$os" = "windows" ]; then
    ext="zip"
fi
url="https://github.com/$repo/releases/download/$version/$filename.$ext"

if [ "$nightly" -eq 1 ]; then
    echo "downloading NIGHTLY build $version..."
else
    echo "downloading flow $version..."
fi

curl -fL "$url" -o "/tmp/$filename.$ext"

# simple file size check (adjust threshold if needed)
filesize=$(stat -c%s "/tmp/$filename.$ext" 2>/dev/null || stat -f%z "/tmp/$filename.$ext")
if [ "$filesize" -lt 100 ]; then
    echo "downloaded file appears to be invalid (size: ${filesize} bytes)"
    exit 1
fi

if [ "$verify" -eq 0 ] && [ -t 0 ]; then
    printf "do you want to download and verify the gpg signature? [y/N]: "
    read -r answer_verify
    if [ "$answer_verify" = "y" ] || [ "$answer_verify" = "Y" ]; then
        verify=1
    fi
fi

if [ "$verify" -eq 1 ]; then
    curl -fL "$url.sig" -o "/tmp/$filename.$ext.sig"
    curl -fL 'https://flow-control.dev/public.gpg' -o /tmp/flow-control-public.gpg
    gpg --no-default-keyring --keyring /tmp/flow-control-public.gpg --verify "/tmp/$filename.$ext.sig" "/tmp/$filename.$ext"

    if [ "$local" -eq 1 ]; then
        gpg --verify "/tmp/$filename.$ext.sig" "/tmp/$filename.$ext"
    fi

    rm /tmp/flow-control-public.gpg
    rm "/tmp/$filename.$ext.sig"
fi

echo "installing $([ "$nightly" -eq 1 ] && echo 'NIGHTLY build' || echo 'flow')..."
if [ "$ext" = "tar.gz" ]; then
    tar -xzf "/tmp/$filename.$ext" -C "$install_dir"
else
    unzip -o "/tmp/$filename.$ext" -d "$install_dir"
fi

chmod +x "$install_dir/flow"
rm "/tmp/$filename.$ext"
echo "$([ "$nightly" -eq 1 ] && echo 'NIGHTLY build' || echo 'flow') installed successfully!"

create_alias() {
    if [ -e "$install_dir/f" ]; then
        echo "warning: existing file or alias detected at $install_dir/f, overwriting..."
        rm -f "$install_dir/f"
    fi
    ln -s "$install_dir/flow" "$install_dir/f"
    echo "alias 'f' created successfully!"
}

if [ "$add_alias" -eq 1 ]; then
    create_alias
elif [ -t 0 ]; then
    printf "do you want to create an alias 'f' for 'flow'? [y/N]: "
    read -r answer_alias
    if [ "$answer_alias" = "y" ] || [ "$answer_alias" = "Y" ]; then
        create_alias
    fi
fi