#!/usr/bin/env bash
# bump-fork.sh — Auto-bump a local fork to match upstream version
#
# Usage: bump-fork.sh <component> [--version=X.Y.Z]
#
# If --version is provided, bumps to that version.
# If --version is omitted, queries Cargo to determine the required version
# from the build graph.
#
# Implements: AGENTS.md "Local Fork Priority and Version Sync (MANDATORY)"

set -euo pipefail

COMPONENT="${1:-}"
if [[ -z "$COMPONENT" ]]; then
    echo "Usage: $0 <component> [--version=X.Y.Z]"
    echo ""
    echo "Components with local forks:"
    for d in local/sources/*/; do
        if [[ -d "$d" ]] && [[ -f "${d}Cargo.toml" ]]; then
            echo "  $(basename "$d")"
        fi
    done
    exit 1
fi

shift

VERSION=""
while [[ $# -gt 0 ]]; do
    case "$1" in
        --version=*)
            VERSION="${1#*=}"
            shift
            ;;
        *)
            echo "Unknown option: $1" >&2
            exit 1
            ;;
    esac
done

LOCAL_DIR="local/sources/${COMPONENT}"
RECIPE_DIR="recipes/core/${COMPONENT}"

if [[ ! -d "$LOCAL_DIR" ]]; then
    echo "ERROR: $LOCAL_DIR does not exist" >&2
    exit 1
fi

# Detect current local version
if [[ -f "${LOCAL_DIR}/Cargo.toml" ]]; then
    CURRENT_VERSION=$(grep -E '^version\s*=' "${LOCAL_DIR}/Cargo.toml" | head -1 | sed 's/.*"\(.*\)".*/\1/')
    echo "Current local version: ${CURRENT_VERSION:-unknown}"
else
    echo "WARNING: ${LOCAL_DIR}/Cargo.toml not found — not a Cargo crate?"
    CURRENT_VERSION=""
fi

# Detect required version from build graph if not specified
if [[ -z "$VERSION" ]]; then
    echo "Querying build graph for required version of ${COMPONENT}..."

    # Search Cargo.lock files for the required version
    REQUIRED_VERSION=""
    while IFS= read -r lockfile; do
        # Look for [[package]] entries that match this component
        entry=$(awk '
            /^name = "'"${COMPONENT}"'"$/ { found=1; next }
            found && /^version = / { gsub(/"/, ""); print; exit }
        ' "$lockfile" 2>/dev/null)
        if [[ -n "$entry" ]]; then
            REQUIRED_VERSION="$entry"
            break
        fi
    done < <(find . -name 'Cargo.lock' -not -path '*/.git/*' 2>/dev/null)

    if [[ -z "$REQUIRED_VERSION" ]]; then
        echo "ERROR: Could not determine required version for ${COMPONENT}" >&2
        echo "       Pass --version=X.Y.Z explicitly" >&2
        exit 1
    fi

    VERSION="$REQUIRED_VERSION"
    echo "Required version (from Cargo.lock): ${VERSION}"
fi

# Check if bump is needed
if [[ -n "$CURRENT_VERSION" ]] && [[ "$CURRENT_VERSION" == "$VERSION" ]]; then
    echo "Local fork already at v${VERSION} — no bump needed"
    exit 0
fi

echo "Bumping ${COMPONENT}: v${CURRENT_VERSION:-unknown} → v${VERSION}"

# Fetch upstream source at the required version
echo "Fetching upstream source at v${VERSION}..."

# Find the upstream repo URL from the recipe
if [[ -f "${RECIPE_DIR}/recipe.toml" ]]; then
    UPSTREAM_GIT=$(grep -E '^git\s*=' "${RECIPE_DIR}/recipe.toml" | head -1 | sed 's/.*"\(.*\)".*/\1/')
fi

if [[ -z "${UPSTREAM_GIT:-}" ]]; then
    echo "ERROR: Cannot determine upstream git URL from ${RECIPE_DIR}/recipe.toml" >&2
    echo "       Set up the recipe or pass --upstream-git=<url>" >&2
    exit 1
fi

echo "Upstream git: ${UPSTREAM_GIT}"

# Fetch into a staging directory
STAGING_DIR="/tmp/redbear-bump-${COMPONENT}-$$"
trap "rm -rf ${STAGING_DIR}" EXIT

echo "Cloning ${UPSTREAM_GIT} at v${VERSION} into ${STAGING_DIR}..."
git clone --depth 1 --branch "v${VERSION}" "${UPSTREAM_GIT}" "${STAGING_DIR}" 2>/dev/null \
    || git clone --depth 1 "${UPSTREAM_GIT}" "${STAGING_DIR}"

cd "${STAGING_DIR}"
git fetch --tags
if git tag -e "v${VERSION}" 2>/dev/null; then
    git checkout "v${VERSION}"
else
    echo "WARNING: tag v${VERSION} not found — using main branch HEAD"
fi
cd - >/dev/null

# Apply Red Bear patches
PATCH_DIR="local/patches/${COMPONENT}"
if [[ -d "$PATCH_DIR" ]]; then
    echo "Applying Red Bear patches from ${PATCH_DIR}..."
    for patch in "${PATCH_DIR}"/*.patch; do
        if [[ -f "$patch" ]]; then
            echo "  Applying $(basename "$patch")..."
            if ! patch -p1 -d "${STAGING_DIR}" --dry-run < "$patch" >/dev/null 2>&1; then
                echo "ERROR: Patch $(basename "$patch") fails to apply to upstream v${VERSION}" >&2
                echo "       Manual intervention required — patch may need rebasing" >&2
                exit 1
            fi
            patch -p1 -d "${STAGING_DIR}" < "$patch"
        fi
    done
fi

# Update version in Cargo.toml
if [[ -f "${STAGING_DIR}/Cargo.toml" ]]; then
    sed -i "s/^version = \"${CURRENT_VERSION}\"/version = \"${VERSION}\"/" "${STAGING_DIR}/Cargo.toml"
fi

# Replace local fork contents with staged (atomic via temp dir rename)
echo "Updating ${LOCAL_DIR}..."
mv "${LOCAL_DIR}" "${LOCAL_DIR}.old-${$$}"
mv "${STAGING_DIR}" "${LOCAL_DIR}"
rm -rf "${LOCAL_DIR}.old-${$$}"

echo ""
echo "SUCCESS: ${COMPONENT} bumped to v${VERSION}"
echo ""
echo "Next steps:"
echo "  1. cd ${LOCAL_DIR}"
echo "  2. git diff (verify patches applied correctly)"
echo "  3. git add -A && git commit -m 'bump: ${COMPONENT} v${CURRENT_VERSION} -> v${VERSION}'"
echo "  4. git push origin submodule/${COMPONENT}"
echo "  5. Rebuild affected packages: ./local/scripts/build-redbear.sh redbear-mini"