#!/bin/sh
set -e

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
ROOT="$(dirname "$SCRIPT_DIR")"
SING_BOX="$ROOT/works/sing-box"
PATCH_DIR="$ROOT/works/patch"
OUTPUT="$ROOT/works/core"
REV_FILE="$ROOT/works/rev"

# defaults
REPO_URL="https://git.sfclub.cc/icybear/sing-box.git"
UPSTREAM_BRANCH="testing"

CONFIG="$ROOT/works/config"
if [ -f "$CONFIG" ]; then
    . "$CONFIG"
fi

# Clone if not present
if [ ! -d "$SING_BOX/.git" ]; then
    echo "Cloning sing-box..."
    if [ -n "$UPSTREAM_BRANCH" ]; then
        git clone -b "$UPSTREAM_BRANCH" "$REPO_URL" "$SING_BOX"
    else
        git clone "$REPO_URL" "$SING_BOX"
    fi
fi

# Checkout stored rev
if [ -f "$REV_FILE" ]; then
    REV="$(cat "$REV_FILE" | tr -d '[:space:]')"
    echo "Checking out stored rev: $REV"
    git -C "$SING_BOX" fetch --all
    git -C "$SING_BOX" checkout "$REV"
else
    echo "Warning: works/rev not found, using current HEAD." >&2
fi

echo "Initializing works/core/ from works/sing-box/ (retaining .git)..."
rm -rf "$OUTPUT"
cp -a "$SING_BOX" "$OUTPUT"

echo "Applying patches..."
applied=0
failed=0
failed_list=""

if [ -d "$PATCH_DIR" ]; then
    patch_list="$(mktemp)"
    trap 'rm -f "$patch_list"' EXIT
    find "$PATCH_DIR" -name "*.patch" | sort > "$patch_list"

    while IFS= read -r patch_file; do
        rel="${patch_file#$PATCH_DIR/}"
        rel="${rel%.patch}"
        dst="$OUTPUT/$rel"

        mkdir -p "$(dirname "$dst")"
        if patch --merge --no-backup-if-mismatch --force "$dst" < "$patch_file"; then
            applied=$((applied + 1))
        else
            echo "  FAILED:  $rel" >&2
            failed=$((failed + 1))
            failed_list="${failed_list}    ${rel}
"
        fi
    done < "$patch_list"
fi

# Commit applied patches to keep history and clean worktree
git -C "$OUTPUT" add -A
git -C "$OUTPUT" commit -m "patches applied" --allow-empty

total=$((applied + failed))
echo ""
echo "Result: $applied/$total patches applied."
if [ "$failed" -gt 0 ]; then
    echo ""
    echo "Failed patches (merge conflicts written to files):"
    printf "%s" "$failed_list"
    exit 1
fi

echo "Done."