将json转换为Gson Style的model

json2model.py

#! /usr/bin/env python3

"""
# install requirements:
 pip3 install fire # 解析命令行参数
 pip3 install simpletemplate # 生成代码
 pip3 install pyperclip # 控制剪切版
 pip3 install termcolor # 彩色打印
"""

import fire
import re
import collections
import jsonp
from pathlib import Path
from simpletemplate import Template
import simpletemplate
from typing import NamedTuple, List, Dict
from pyperclip import copy, paste
from termcolor import cprint
from subprocess import check_output

simpletemplate.DEBUG_TEMPLATE = False


class JField(NamedTuple):
    j_type: str
    name: str
    raw: str


class JClass(NamedTuple):
    name: str
    fields: List[JField]


def _author():
    return check_output("whoami").decode("utf-8").strip()


def gen_class_name(name: str) -> str:
    if not name:
        return f"Model"
    return f"{name[0].upper()}{name[1:]}"


def gen_field_name(field: str) -> str:
    return f"m{field[0].upper()}{field[1:]}"


g_class: List[JClass] = []
pojo = JClass("Model", [])


def json2pojo(_json, recommand_name: str = None, toplevel=False):
    if isinstance(_json, list) and len(_json) > 0:
        t = json2pojo(_json[0], recommand_name)
        return f"List<{t}>"
    elif isinstance(_json, dict):
        jclass: JClass = pojo if toplevel else JClass(
            gen_class_name(recommand_name), []
        )
        for k, v in _json.items():
            t = json2pojo(v, k)
            jclass.fields.append(JField(t, gen_field_name(k), k))
        if not toplevel:
            g_class.append(jclass)
        return jclass.name
    elif isinstance(_json, list):
        return "List"
    elif isinstance(_json, bool):
        return "boolean"
    elif isinstance(_json, str):
        return "String"
    elif isinstance(_json, float):
        return "double"
    elif isinstance(_json, int):
        return "int"
    else:
        assert False, f"unknown json type: {_json}"


def serialid():
    import random

    li = [str(random.randrange(0, 10)) for _ in range(19)]
    return "".join(li)


TEMPLATE = r"""\
import java.io.Serializable;
import java.util.List;
import com.google.gson.annotations.SerializedName;

/**
 * 
 * @author {{author}} 
 */
public class {{pojo.name}} implements Serializable {
    private static final long serialVersionUID = {{serialid()}}L;

%{for f in pojo.fields:}%
    @SerializedName(\"{{f.raw}}\")
    public {{f.j_type}} {{f.name}};
%{end}%
%{for cls in cls_defs:}%
    public static class {{cls.name}} implements Serializable {
        private static final long serialVersionUID = {{serialid()}}L;
%{for f in cls.fields:}%
        @SerializedName(\"{{f.raw}}\")
        public {{f.j_type}} {{f.name}};
%{end}%
    }
%{end}%
}\
"""


def chain(arg, *funcs):
    r = arg
    for f in funcs:
        r = f(r)
    return r


def parse(_json: str) -> Dict:
    if not _json:
        raise SystemExit("empty json", -1)
    try:
        return jsonp.loads(_json)
    except Exception as e:
        print("json:", _json)
        raise SystemExit("invalid json format", -1)


def remove_json_comment(_json: str) -> str:
    return re.sub(r'//[^"}{]*\n', "\n", _json)


def get_json(file: str):
    if not file:
        return paste()
    p = Path(file)
    if p.exists():
        return p.read_text()
    else:
        raise SystemExit(f"file {file} not exists", -1)


def main(file: str = None):

    _json = chain(file, get_json, str.strip, remove_json_comment, parse)
    print(_json)

    json2pojo(_json, toplevel=True)

    code = Template(TEMPLATE).render(
        {"pojo": pojo, "cls_defs": g_class, "serialid": serialid, "author": _author()}
    )
    sep = "=" * 30
    cprint(code, "yellow")
    cprint(f"{sep} code already copy info clipboard, just paste {sep}", "green")
    copy(code)


if __name__ == "__main__":
    fire.Fire(main)