#!/usr/bin/env sh

# This script generates an AI-powered commit message using dotnet-aicommitmessage.
# It can be bypassed by setting the GIT_AICOMMIT_SKIP environment variable.

# Exit immediately if GIT_AICOMMIT_SKIP is set
if [ -n "$GIT_AICOMMIT_SKIP" ]; then
    exit 0
fi

# Check if dotnet-aicommitmessage is installed and in PATH
if ! command -v dotnet-aicommitmessage >/dev/null 2>&1; then
    echo "Error: dotnet-aicommitmessage is not installed or not in PATH" >&2
    echo "Please install it by running 'dotnet tool install -g aicommitmessage'" >&2
    exit 1
fi

# Ensure the commit message file is provided
if [ -z "$1" ]; then
    echo "Error: Commit message file not provided" >&2
    exit 1
fi

COMMIT_MSG_FILE="$1"

# Check if the commit message file exists
if [ ! -f "$COMMIT_MSG_FILE" ]; then
    echo "Error: Commit message file '$COMMIT_MSG_FILE' not found" >&2
    exit 1
fi

# Read the current commit message
CURRENT_MESSAGE=$(cat "$COMMIT_MSG_FILE")

# Backup the commit message file
cp "$COMMIT_MSG_FILE" "${COMMIT_MSG_FILE}.bak"

# Generate the AI commit message
if ! AI_MESSAGE=$(dotnet-aicommitmessage generate-message -m "$CURRENT_MESSAGE" 2>/dev/null); then
    echo "Error: Failed to generate AI commit message. Using original message." >&2
    exit 0
fi

# Check if the generated message is empty
if [ -z "$AI_MESSAGE" ] || echo "$AI_MESSAGE" | grep -q '^[[:space:]]*$'; then
    echo "Error: Generated commit message is empty." >&2
    exit 1
fi

# Write the new commit message back to the file
if ! echo "$AI_MESSAGE" > "$COMMIT_MSG_FILE" 2>/dev/null; then
    echo "Error: Failed to write new commit message" >&2
    cp "${COMMIT_MSG_FILE}.bak" "$COMMIT_MSG_FILE"
    rm "${COMMIT_MSG_FILE}.bak"
    exit 1
fi

# Remove the backup file
rm "${COMMIT_MSG_FILE}.bak"
exit 0
