#!/usr/bin/env bash
# PostToolUse hook: format and lint edited/written files.
# Dispatches to project-local formatters/ directory (symlinks to claude-foundations/formatters/).
#
# Input: JSON on stdin with tool_name, file_path, cwd fields
# Exit 0: silent pass (no formatter, clean lint, or missing tools)
# Exit 2: lint errors remain — stderr fed back to Claude as feedback

# Parse stdin JSON for file_path and cwd
INPUT="$(cat)"
FILE_PATH="$(echo "$INPUT" | python3 -c "import sys,json; d=json.load(sys.stdin); print(d.get('file_path',''))" 2>/dev/null)"
CWD="$(echo "$INPUT" | python3 -c "import sys,json; d=json.load(sys.stdin); print(d.get('cwd',''))" 2>/dev/null)"

# No file path — nothing to do
[ -z "$FILE_PATH" ] && exit 0

# Make path absolute if relative
if [[ "$FILE_PATH" != /* ]]; then
    FILE_PATH="${CWD:-.}/$FILE_PATH"
fi

# File must exist
[ -f "$FILE_PATH" ] || exit 0

# Extract extension (normalise yml → yaml)
EXT="${FILE_PATH##*.}"
case "$EXT" in
    yml) EXT="yaml" ;;
esac

# No extension — nothing to do
[ -z "$EXT" ] || [ "$EXT" = "$FILE_PATH" ] && exit 0

# Find the project's formatters/ directory by walking up from cwd
find_formatters_dir() {
    local dir="${1:-$CWD}"
    while [ "$dir" != "/" ] && [ -n "$dir" ]; do
        if [ -d "$dir/formatters" ]; then
            echo "$dir/formatters"
            return 0
        fi
        dir="$(dirname "$dir")"
    done
    return 1
}

FORMATTERS_DIR="$(find_formatters_dir "$CWD")"
[ -z "$FORMATTERS_DIR" ] && exit 0

# Check if a formatter exists for this extension
FORMATTER="$FORMATTERS_DIR/$EXT"
[ -x "$FORMATTER" ] || exit 0

# --- Checkpoint: save pre-format content ---
if git -C "$(dirname "$FILE_PATH")" rev-parse --git-dir >/dev/null 2>&1; then
    # Inside a git repo — use git hash-object for efficient checkpoint
    BLOB="$(git -C "$(dirname "$FILE_PATH")" hash-object -w "$FILE_PATH" 2>/dev/null)"
    if [ -n "$BLOB" ]; then
        echo "$BLOB" > "${FILE_PATH}.pre-lint"
    fi
else
    # Not a git repo — fall back to file copy
    cp "$FILE_PATH" "${FILE_PATH}.pre-lint"
fi

# --- Run formatter ---
LINT_OUTPUT=$("$FORMATTER" "$FILE_PATH" 2>&1)
FORMATTER_EXIT=$?

if [ $FORMATTER_EXIT -eq 0 ]; then
    # Clean — remove checkpoint
    rm -f "${FILE_PATH}.pre-lint"
    exit 0
fi

# --- Lint errors remain ---
# Keep .pre-lint for revert, exit 2 to feed errors back to Claude
{
    echo "Lint errors in ${FILE_PATH}:"
    echo "$LINT_OUTPUT"
    echo ""
    echo "To fix: use the Agent tool to resolve these lint errors (keeps fix loop out of main context)."
    echo "To revert formatting: git cat-file blob \$(cat ${FILE_PATH}.pre-lint) > ${FILE_PATH}"
} >&2

exit 2