from typing import Optional
import argparse
import sys
import os
from pathlib import Path

VERSION = "development"

def parse_args():
    parser = argparse.ArgumentParser(description="Generates Python bindings for a Pkl module")
    
    # Positional argument for module
    parser.add_argument('module', help="The module for which to generate bindings", nargs="?")

    # Optional arguments
    parser.add_argument('--generator-settings', help="The path to a generator settings file", default="")
    parser.add_argument('--output-path', help="The output directory to write generated sources into", default="")
    parser.add_argument('--base-path', help="The base path used to determine relative output", default="")
    parser.add_argument('--mapping', action='append', help="The mapping of a Pkl module name to a Python package name", default=[])
    parser.add_argument('--suppress-format-warning', action='store_true', help="Suppress warnings around formatting issues")
    parser.add_argument('--allowed-modules', action='append', help="URI patterns that determine which modules can be loaded and evaluated", default=[])
    parser.add_argument('--allowed-resources', action='append', help="URI patterns that determine which resources can be loaded and evaluated", default=[])
    parser.add_argument('--project-dir', help="The project directory to load dependency and evaluator settings from", default="")
    parser.add_argument('--dry-run', action='store_true', help="Print out the names of the files that will be generated, but don't write any files")
    # parser.add_argument('--version', action='store_true', help="Print the version and exit")

    return parser.parse_args()

def find_project_dir(start_path: str) -> Optional[str]:
    current_path = Path(start_path)
    while current_path != current_path.parent:
        if (current_path / "PklProject").exists():
            return str(current_path)
        current_path = current_path.parent
    return None


// Loads the settings for controlling codegen.
// Uses a Pkl evaluator that is separate from what's used for actually running codegen.
func loadGeneratorSettings(generatorSettingsPath string, projectDirFlag string) (*generatorsettings.GeneratorSettings, error) {
	projectDir := findProjectDir(projectDirFlag)
	var evaluator pkl.Evaluator
	var err error
	if projectDir != "" {
		evaluator, err = pkl.NewProjectEvaluator(context.Background(), projectDir, pkl.PreconfiguredOptions)
	} else {
		evaluator, err = pkl.NewEvaluator(context.Background(), pkl.PreconfiguredOptions)
	}
	if err != nil {
		panic(err)
	}
	var source *pkl.ModuleSource
	if generatorSettingsPath != "" {
		source = pkl.FileSource(generatorSettingsPath)
	} else if fileExists("generator-settings.pkl") {
		source = pkl.FileSource("generator-settings.pkl")
	} else {
		source = generatorSettingsSource()
	}
	return generatorsettings.Load(context.Background(), evaluator, source)
}

def load_generator_settings(generator_settings_path, project_dir_flag):
    project_dir = find_project_dir(project_dir_flag)
    evaluator = None  # Placeholder for evaluator initialization
    # Initialize your evaluator here based on project_dir, if applicable

    settings_path = generator_settings_path if generator_settings_path else "generator-settings.pkl"
    if not os.path.exists(settings_path):
        # Fallback to a default source or handle error
        print("Settings file not found.")
        return None

    with open(settings_path, 'r') as settings_file:
        settings = json.load(settings_file)
        # Assuming the settings file is in JSON format
        # For YAML, use `settings = yaml.safe_load(settings_file)`

    # Placeholder: Load and return the settings using the evaluator
    # This part of the logic will depend on how you intend to use the settings and the evaluator
    return settings


def main():
    args = parse_args()

    if not args.module:
        print("Error: Module name is required.")
        sys.exit(1)

    project_dir = find_project_dir(os.getcwd())
    evaluator = PklEvaluator(project_dir)
    settings = {}
    if args.generator_settings:
        settings = load_generator_settings(args.generator_settings, project_dir)

    # Placeholder for the main logic to generate Python bindings.
    # You would need to implement this based on how the Python bindings are generated from Pkl files.
    print(f"Generating bindings for module: {args.module} with settings: {settings} and output path: {args.output_path}")

if __name__ == "__main__":
    main()
