#!/usr/bin/env bash
# init_from_upstream.sh — bootstrap a new Exiles addon fork from upstream.
#
# Usage:
#   tools/init_from_upstream.sh <upstream-url> <AddonFolderName> [upstream-branch]
#
# Example:
#   tools/init_from_upstream.sh https://github.com/Ascension-Addons/CallToArms CallToArms
#
# What it does:
#   1. Adds `upstream` remote and fetches it.
#   2. Squash-imports the upstream tree at the named branch (default master/main)
#      into <AddonFolderName>/ at the repo root.
#   3. Leaves you with a single staged commit you review and finalise.
#
# What it does NOT do:
#   - Push anything.
#   - Tag anything.
#   - Modify the upstream history (it's a squash import, not a merge).
#
# After running, verify with:
#   bash tools/build_zip.sh
#   unzip -l dist/<AddonFolderName>.zip | head -5
# then `git commit --amend` if you want to edit the message, push,
# and tag <upstream-version>-coa.1 to trigger the first release.
set -euo pipefail

if [ "$#" -lt 2 ] || [ "$#" -gt 3 ]; then
    echo "usage: $0 <upstream-url> <AddonFolderName> [upstream-branch]" >&2
    exit 2
fi

upstream_url=$1
folder=$2
branch=${3:-}

if [ -d "$folder" ]; then
    echo "refusing to overwrite existing folder $folder/" >&2
    exit 1
fi

if ! git remote get-url upstream >/dev/null 2>&1; then
    git remote add upstream "$upstream_url"
else
    git remote set-url upstream "$upstream_url"
fi

echo "==> fetching upstream"
git fetch --tags upstream

if [ -z "$branch" ]; then
    # Try master, then main.
    if git rev-parse --verify "upstream/master" >/dev/null 2>&1; then
        branch=master
    elif git rev-parse --verify "upstream/main" >/dev/null 2>&1; then
        branch=main
    else
        echo "couldn't find upstream/master or upstream/main; pass branch explicitly" >&2
        exit 1
    fi
fi
echo "==> importing tree from upstream/$branch into $folder/"

# Extract upstream tree into a temporary worktree-like dir, then move into folder.
tmp=$(mktemp -d)
trap 'rm -rf "$tmp"' EXIT
git archive "upstream/$branch" | tar -x -C "$tmp"
mkdir -p "$folder"
# rsync preserves dotfiles; --exclude keeps obvious noise out.
rsync -a --exclude '.git/' --exclude '.github/' --exclude '.gitea/' \
      --exclude '.idea/' --exclude '.vscode/' --exclude '.DS_Store' \
      "$tmp"/ "$folder"/

git add "$folder"
upstream_sha=$(git rev-parse "upstream/$branch")
upstream_short=$(git rev-parse --short "upstream/$branch")
git commit -m "Import $folder from upstream@$upstream_short

upstream: $upstream_url
branch:   $branch
commit:   $upstream_sha"

cat <<EOF

==> done. next steps:
    1. bash tools/build_zip.sh
    2. unzip -l dist/$folder.zip | head -5
       (expect first entry: $folder/)
    3. git push origin master
    4. Read $folder/$folder.toc — look for the version string.
       Tag with <upstream-version>-coa.1, e.g.:
         git tag -a 1.2.3-coa.1 -m "first Exiles release"
         git push origin 1.2.3-coa.1
       The release workflow picks it up and publishes
       https://git.sub-net.at/Exiles/<this-repo>/releases/tag/<tag>.

    The upstream remote stays configured so future rebases / re-imports
    are one-line: \`git fetch upstream && ...\`.
EOF