import os
import datetime
import tempfile
import traceback

# Inform that the script is starting
print("[Automation Script] Starting build information generation...")

# --- Configuration ---
# Use pathlib for more robust path manipulations
from pathlib import Path

# Derive PROJECT_ROOT more cleanly
PROJECT_ROOT = Path(__file__).resolve().parent.parent
MODULE_NAME = "TheCulling"
OUTPUT_DIR = PROJECT_ROOT / 'Source' / MODULE_NAME / 'Public'
OUTPUT_FILENAME = 'BuildInformation.h'
VERSION_FILE = OUTPUT_DIR / 'last_version_info.txt'

BUILDS_PER_MINOR = 100  # Number of builds before minor increments
MINOR_MAX = 9           # Number of minors before major increments

# --- Helper Functions ---
def read_version_info(version_file_path: Path):
    """Reads the last version information from a file."""
    try:
        if version_file_path.exists():
            with open(version_file_path, 'r') as f:
                line = f.read().strip()
                parts = line.split(',')
                if len(parts) == 6:
                    return map(int, parts)
                else:
                    print(f"[Automation Script] Warning: Malformed version file '{version_file_path}'. Resetting version.")
        return None
    except Exception as ex:
        print(f"[Automation Script] Error reading version info from '{version_file_path}': {ex}")
        traceback.print_exc()
        return None

def write_version_info(version_file_path: Path, major, minor, patch, build, week, year):
    """Writes the current version information to a file using a temporary file for atomic write."""
    try:
        # Ensure the output directory exists
        version_file_path.parent.mkdir(parents=True, exist_ok=True)

        with tempfile.NamedTemporaryFile('w', dir=version_file_path.parent, delete=False) as tf:
            tf.write(f"{major},{minor},{patch},{build},{week},{year}")
            temp_filepath = Path(tf.name)
        temp_filepath.replace(version_file_path)
    except Exception as ex:
        print(f"[Automation Script] Error writing version info to '{version_file_path}': {ex}")
        traceback.print_exc()
        exit(1) # Exit if we can't save version, as it will affect next build's numbering

# --- Main Logic ---
def main():
    now = datetime.datetime.now()
    build_date = now.strftime("%Y-%m-%d")
    build_time = now.strftime("%H:%M:%S")
    current_week = now.isocalendar()[1]
    current_year = now.year

    # Defaults
    major, minor, patch, build = 0, 1, 0, 0
    last_week = current_week
    last_year = current_year

    # Read last version info or initialize
    version_data = read_version_info(VERSION_FILE)
    if version_data:
        major, minor, patch, build, last_week, last_year = version_data
    else:
        # If reading failed or file was malformed, reset and write immediately
        write_version_info(VERSION_FILE, major, minor, patch, build, last_week, last_year)

    # Versioning rules
    if current_week == last_week and current_year == last_year:
        patch += 1
    else:
        patch = 0  # Reset patch for new week or year

    build += 1

    if build > BUILDS_PER_MINOR:
        build = 1
        minor += 1
        if minor > MINOR_MAX:
            minor = 1
            major += 1

    game_version_major = major
    game_version_minor = minor
    game_version_patch = patch
    current_build_number = build

    game_version_string = f"{game_version_major}.{game_version_minor}.{game_version_patch}.{current_build_number}"

    # --- Generate Header File Content ---
    header_content = f"""// THIS FILE IS AUTOMATICALLY GENERATED BY THE BUILD SYSTEM. DO NOT EDIT MANUALLY.
#pragma once

#define GAME_BUILD_NUMBER {current_build_number}
#define GAME_VERSION_MAJOR {game_version_major}
#define GAME_VERSION_MINOR {game_version_minor}
#define GAME_VERSION_PATCH {game_version_patch}
#define GAME_VERSION_STRING TEXT("{game_version_string}")
#define GAME_BUILD_DATE TEXT("{build_date}")
#define GAME_BUILD_TIME TEXT("{build_time}")
// Add more build info as needed, e.g., git hash, changelist, etc.
"""

    # --- Write the Header File ---
    output_path = OUTPUT_DIR / OUTPUT_FILENAME
    OUTPUT_DIR.mkdir(parents=True, exist_ok=True) # Ensure output directory exists

    try:
        with open(output_path, 'w') as f:
            f.write(header_content)
        print(f"[Automation Script] Successfully generated {output_path}")

        # Save version info for next run
        write_version_info(VERSION_FILE, game_version_major, game_version_minor, game_version_patch, current_build_number, current_week, current_year)

    except Exception as e:
        print(f"[Automation Script] ERROR: Failed to write {output_path}: {e}")
        traceback.print_exc()
        exit(1)

    print("[Automation Script] Execution Ended.")

if __name__ == "__main__":
    main()