'''
Generate a definition file with a global namespace
from a typescript module definition file
'''

import os
import pathlib
import re
import argparse

parser = parser = argparse.ArgumentParser(description='Generate a definition file with a global namespace from a typescript module definition file')
parser.add_argument('namespace',
                    help='Namespace used in the global script. (example: Three.js use THREE as its namespace)')
parser.add_argument('output_filename',
                    help='Output d.ts definition file. (example: three.d.ts)')

args = parser.parse_args()

output_filename = args.output_filename
namespace = args.namespace


import_pattern = re.compile(
        r"import(?:[\"'\s]*([\w*{}\n\r\t, ]+)from\s*)?[\"'\s].*([@\w_-]+)[\"'\s].*;"
    )
export_pattern = re.compile(
        r"export ([*] from [\"'\s].*[\"'\s]|{.*}(?: from [\"'\s].*[\"'\s])?);"
    )

filter_directories = ["./Enums", "./Interfaces"]

def main():
    '''
    Entry point function
    '''
    with open(output_filename, 'w') as output_file:
        output_file.write(('declare namespace {} {{\n'.format(namespace)))
        for root, subdirs, files in os.walk('./'):
            if root not in filter_directories:
                continue

            print('--\nroot = ' + root)

            for subdir in subdirs:
                print('\t- subdirectory ' + subdir)

            for filename in files:
                if filename == 'output.d.ts':
                    continue

                if filename == 'my-directory-list.txt':
                    os.remove(os.path.join(root, filename))
                    continue

                suffixes = pathlib.Path(filename).suffixes
                if (suffixes != ['.d', '.ts']):
                    continue

                file_path = os.path.join(root, filename)
                file_path = file_path.replace('\\', '/')

                print('\t- file %s (full path: %s)' % (filename, file_path))
                with open(file_path, 'r') as cur_file:
                    f_content = cur_file.read()

                    # removes imports
                    # see https://gist.github.com/manekinekko/7e58a17bc62a9be47172
                    f_content = import_pattern.sub('', f_content)

                    # Replace 'export { my_class as synonym };'
                    # => 'class synonym extend my_class {}'
                    f_content = re.sub(
                        r"export ({ ([A-Z].*) as ([A-Z].*) });",
                        "export class \\g<3> extends \\g<2> {}",
                        f_content,
                        0,
                        re.MULTILINE
                    )

                    # Replace 'export declare class' => 'export class'
                    f_content = re.sub(r"export (declare) class", 'export class', f_content, 0, re.MULTILINE)
                    f_content = re.sub(r"export (declare) enum", 'export enum', f_content, 0, re.MULTILINE)
                    f_content = re.sub(r"export (declare) function", 'export function', f_content, 0, re.MULTILINE)
                    f_content = re.sub(r"export (declare) type", 'export type', f_content, 0, re.MULTILINE)

                    # Replace 'export { my_func as synonym }' => 'export function synonym = my_func'

                    # Replace 'export default class' => 'export class'
                    f_content = re.sub(r"(export) default", "\\1", f_content, 0, re.MULTILINE)

                    # Replace other exports : 'export { .* } from '.*';' and 'export [*] from '.*';
                    f_content = export_pattern.sub('', f_content)

                    # Specific to your module
                    f_content = re.sub('export as namespace {};'.format(namespace), '', f_content)

                    output_file.write(f_content)
                    output_file.write('\n')
        output_file.write(('}\n'))

main()