#!/usr/bin/env nix-shell
#! nix-shell -i bash -p curl xmlstarlet nix coreutils
set -euxo pipefail

SCRIPTPATH="$( cd "$(dirname "$0")" ; pwd -P )"
cd $SCRIPTPATH

function update_savannah_branch() {
    branch=$1
    echo emacs $branch

    # Get relevant data (commit id and timestamp) for the latest commit
    commit_data=$(curl "https://git.savannah.gnu.org/cgit/emacs.git/atom/?h=$branch" | xmlstarlet sel -N atom="http://www.w3.org/2005/Atom" -t -m /atom:feed/atom:entry -v "concat(atom:id,'/',atom:updated)" -n | head -n 1)

    # Extract commit sha and build a version number based on date: YYYYMMDD.0
    commit_sha=$(echo $commit_data | cut -d '/' -f 1)
    version_number=$(echo $commit_data | cut -d '/' -f 2 | cut -d 'T' -f 1 | sed 's/-//g').0

    output_branch=$(echo $branch | sed s/"\/"/"_"/)
    digest=$(nix-prefetch-url --unpack "https://git.savannah.gnu.org/cgit/emacs.git/snapshot/emacs-${commit_sha}.tar.gz")
    echo "{\"type\": \"savannah\", \"repo\": \"emacs\", \"rev\": \"${commit_sha}\", \"sha256\": \"${digest}\", \"version\": \"${version_number}\"}" > emacs-$output_branch.json
}

function update_github_repo() {
    owner=$1
    repo=$2
    branch=$3
    output_name=$4
    echo $repo $branch

    # Get relevant data (commit id and timestamp) for the latest commit
    commit_data=$(curl "https://github.com/$owner/$repo/commits/$branch.atom" | xmlstarlet sel -N atom="http://www.w3.org/2005/Atom" -t -m /atom:feed/atom:entry -v "concat(atom:id,'/',atom:updated)" -n | head -n 1)

    # Extract commit sha and build a version number based on date: YYYYMMDD.0
    commit_sha=$(echo $commit_data | cut -d '/' -f 2)
    version_number=$(echo $commit_data | cut -d '/' -f 3 | cut -d 'T' -f 1 | sed 's/-//g').0

    digest=$(nix-prefetch-url --unpack "https://github.com/$owner/$repo/archive/${commit_sha}.tar.gz")
    echo "{\"type\": \"github\", \"owner\": \"${owner}\", \"repo\": \"${repo}\", \"rev\": \"${commit_sha}\", \"sha256\": \"${digest}\", \"version\": \"${version_number}\"}" > $repo-$output_name.json
}

function update_release() {
    echo emacs release

    tag=$(git ls-remote --tags --refs --sort=-v:refname https://git.savannah.gnu.org/git/emacs.git 'emacs-[1-9]*' | grep -Eo 'emacs-.*' | grep -v '\-rc' | head -n1)

    digest=$(nix-prefetch-url --unpack "https://git.savannah.gnu.org/cgit/emacs.git/snapshot/${tag}.tar.gz")
    version_number=$(echo $tag | cut -d '-' -f 2)

    echo "{\"type\": \"savannah\", \"repo\": \"emacs\", \"rev\": \"${tag}\", \"sha256\": \"${digest}\", \"version\": \"${version_number}\"}" > emacs-unstable.json
}

update_savannah_branch master
update_release
update_github_repo emacs-lsp emacs json-rpc lsp
update_github_repo commercial-emacs commercial-emacs master commercial-emacs

nix-build --no-out-link --show-trace ./test.nix
