squash-cinnamon-upgpkg-commits.sh

#!/usr/bin/env bash

# motivation
# during release cycle mint sometimes can release 5-20 updates in a day,
# and most of them are "just translations". fixup these commits.

nix_eval_wip() {
    # $1: expression
    # ret: result
    ret_nix_eval_wip=$(NIX_PATH=nixpkgs=. \
        nix-instantiate --expr "with import <nixpkgs> { }; ${1}" --eval | \
        sed 's/^"//' | sed 's/"$//')
}

nix_eval_checkout() {
    # $1: expression
    # $2: checkout
    # ret: result
    ret_nix_eval_checkout=$(nix eval \
        "git+file://$(pwd)?ref=${2}#${1}" --raw)
}

is_running_in_nixpkgs() {
    # ret: 0 for yes, else no
    nix_eval_wip "cinnamon.cinnamon-common.meta.homepage"
    echo "${ret_nix_eval_wip}" | grep "https://github.com/linuxmint/cinnamon"
    ret_is_running_in_nixpkgs=${?}
}

is_worktree_clean() {
    # ret: 0 for yes, 1 for no
    if [ -z "$(git status --porcelain)" ]; then 
        echo "Worktree clean"
        ret_is_worktree_clean=0
    else
        git status
        echo "The git repo has uncommitted changes, please confirm"
        read
        ret_is_worktree_clean=1
    fi
}

git_reset() {
    # $1: commit reset to, no --hard
    echo "You are currently on:"
    git rev-parse HEAD
    git reset $1
}

get_cinnamon_pkgs_attr() {
    local url="https://raw.githubusercontent.com/bobby285271/what-changed/master/data/003-cinnamon.json"
    echo "Fetch cinnamon info: $url"
    # This works f**king well since I maintain this
    ret_get_cinnamon_pkgs_attr=$(curl $url | \
        grep '"attr_path": "' | sed 's/ //g' | sed 's/"attr_path":"//g' | sed 's/"$//g')
}

echo_yellow() {
    # $1: text to echo
    echo -e "\033[0;33m${1}\033[0m"
}

commit_pkgs_change() {
    # $1: pkgs attr
    # $2: base commit
    echo_yellow "Processing $1"

    nix_eval_checkout "${1}.version" "$2"
    local old_version=$ret_nix_eval_checkout

    nix_eval_wip "${1}.version"
    local new_version=$ret_nix_eval_wip

    nix_eval_checkout "${1}.src.rev" "$2"
    local old_rev=$ret_nix_eval_checkout

    nix_eval_wip "${1}.src.rev"
    local new_rev=$ret_nix_eval_wip

    if [ "$new_rev" == "$old_rev" ]; then
        return
    fi

    nix_eval_wip "${1}.src.meta.homepage"
    local diffurl="$ret_nix_eval_wip/compare/${old_rev}...${new_rev}"

    nix_eval_wip "${1}.meta.position"
    local dir_to_add=$(dirname $(echo $ret_nix_eval_wip | cut -d : -f 1))

    echo_yellow "-> Dir to add: $dir_to_add"
    git add $dir_to_add
    git commit -m "${1}: ${old_version} -> ${new_version}" -m "${diffurl}"
}

main() {
    if [ "$#" != 1 ]; then
        echo "Expect exactly one arg for base commit" && exit 1
    fi

    is_running_in_nixpkgs
    if [ "$ret_is_running_in_nixpkgs" != 0 ]; then
        echo "You must run in nixpkgs root" && exit 1
    fi

    is_worktree_clean
    git_reset "$1"

    get_cinnamon_pkgs_attr

    for attr in $(echo $ret_get_cinnamon_pkgs_attr); do
        commit_pkgs_change "$attr" "$1"
    done
}

main "$@"