import json
from enum import Enum
import re

def init_project():
    # validate_values()
    version = Version.from_file('build.gradle')
    version.increment(ReleaseLevel.SNAPSHOT)
    version.write()

def prepare_release():
    pass

def release_in_git():
    pass

class ReleaseLevel(Enum):
    MAJOR = 0
    MINOR = 1
    PATCH = 2
    SNAPSHOT = 3

class Version():

    def __init__(self, version, is_snapshot):
        self.version = version
        self.is_snapshot = is_snapshot

    @classmethod
    def from_file(cls, config_file_path):
        ret_cls = cls(None, False)
        ret_cls.config_file_path = config_file_path
        ret_cls.config_file_type = config_file_path.split('.')[-1]
        ret_cls.parse()
        return ret_cls

    def parse(self):
        match self.config_file_type:
            case 'json':
                self.__parse_json()
            case 'gradle':
                self.__parse_gradle()
            case _:
                raise Exception(f'The file type "{self.config_file_type}" is not implemented')

    def __parse_json(self):
        with open(self.config_file_path, 'r') as json_file:
            json_version = json.load(json_file)['version']
            if '-SNAPSHOT' in json_version:
                self.is_snapshot = True
                json_version = json_version.replace('-SNAPSHOT', '')
            self.version = [int(x) for x in json_version.split('.')]

    def __parse_gradle(self):
        with open(self.config_file_path, 'r') as gradle_file:
            contents = gradle_file.read()
            version_line = re.search("\nversion = .*\n", contents)
            if version_line is None:
                raise Exception("Version not found in gradle file")
            version_line = version_line.group()
            version_string = re.search('[0-9]*\\.[0-9]*\\.[0-9]*(-SNAPSHOT)?', version_line)
            if version_string is None:
                raise Exception("Version not found in gradle file")
            
            version_string = version_string.group()
            if '-SNAPSHOT' in version_string:
                self.is_snapshot = True
                version_string = version_string.replace('-SNAPSHOT', '')

            self.version = [int(x) for x in version_string.split('.')]


    def increment(self, level: ReleaseLevel):
        self.is_snapshot = False
        match level:
            case ReleaseLevel.SNAPSHOT:
                self.is_snapshot = True
            case ReleaseLevel.PATCH:
                self.version[ReleaseLevel.PATCH.value] += 1
            case ReleaseLevel.MINOR:
                self.version[ReleaseLevel.PATCH.value] =  0
                self.version[ReleaseLevel.MINOR.value] += 1
            case ReleaseLevel.MAJOR:
                self.version[ReleaseLevel.PATCH.value] =  0
                self.version[ReleaseLevel.MINOR.value] =  0
                self.version[ReleaseLevel.MAJOR.value] += 1

    def write(self):
        match self.config_file_type:
            case 'json':
                self.__write_json()
            case 'gradle':
                self.__write_gradle()
            case _:
                raise Exception(f'The file type "{self.config_file_type}" is not implemented')

    def __write_json(self):
        with open(self.config_file_path, 'r+') as json_file:
            json_data = json.load(json_file)
            json_data['version'] = self.get()
            json_file.seek(0)            
            json.dump(json_data, json_file, indent=4)
            json_file.truncate()

    def __write_gradle(self):
        with open(self.config_file_path, 'r+') as gradle_file:
            gradle_contents = gradle_file.read()
            version_substitute = re.sub("\nversion = .*\n", f'\nversion = "{self.get()}"\n', gradle_contents)
            gradle_file.seek(0)
            gradle_file.write(version_substitute)
            gradle_file.truncate()

    def get(self) -> str:
        version_string = ".".join([str(x) for x in self.version])
        if self.is_snapshot:
            version_string += "-SNAPSHOT"
        return version_string