#!/bin/sh

set -e

usage() {
    printf \
        'Update flake and heartwood-version to the requested heartwood version.
When called without arguments, reads HASH from tests/support/hearwood-version.

USAGE:
  update-flake [-h] [PATH|HASH]

OPTIONS:
  PATH\t\tPath to heartwood git repo; uses current HEAD.
  HASH\t\tUpdate heartwood version to HASH.
  -h --help\tPrint this help.\n'
}

while [ $# -ne 0 ]; do
    case $1 in
        --help | -h)
            usage >&2
            exit
            ;;
        */*)
            hash=$(git -C "$1" rev-parse --verify HEAD)
            shift
            ;;
        *)
            hash=$1
            shift
            ;;
    esac
done

# Heartwood repo id
rid=z3gqcJUoA1n9HaHKufZs5FCSGazv5

# Some root detection guess work...
root=$(git rev-parse --show-toplevel 2>/dev/null || echo "$PWD")
if [ ! -e "$root/tests/support/heartwood-version" ]; then
    root=$(cd .. ; pwd)
fi

if [ -z "$hash" ]; then
    # No hash given, take from heartwood-version
    if [ -e "$root/tests/support/heartwood-version" ]; then
        hash=$(cat "$root/tests/support/heartwood-version")
        [ -n "$hash" ] || {
            printf "Error reading heartwood-version\n" >&2
            exit 1
        }
    fi
else
    printf '%s\n' "$hash" >$root/tests/support/heartwood-version
fi

if [ -e "$root/flake.nix" ]; then
    sed -E -e '/url.*git\+https.*'"$rid"'/s/(rev=)[0-9a-f]{40,40}/\1'"$hash"'/' "$root/flake.nix" >$root/flake.nix.tmp
    mv "$root/flake.nix.tmp" "$root/flake.nix"

    # If running on a nix-enabled system, also update npmDepsHash.
    if type nix >/dev/null 2>&1; then
        npmDepsHash=$(nix --experimental-features 'nix-command flakes' \
            run --inputs-from "$root" nixpkgs#prefetch-npm-deps \
            -- "$root/package-lock.json")
        sed -E -e '/npmDepsHash/s#".*"#"'"$npmDepsHash"'"#' "$root/flake.nix" >$root/flake.nix.tmp
        mv "$root/flake.nix.tmp" "$root/flake.nix"

        nix --experimental-features 'nix-command flakes' flake update "$root"
    else
        printf >&2 'Node dependencies may be out of date!
Re-run on a nix-enabled system to update npmDepsHash.\n'
    fi
fi