#!/usr/bin/python3

import sys
import os.path
import argparse
import json

import requests

# Shelly advises chunks for script uploading.
CHUNK_SIZE = 1024


def upload(host, file):
    shelly = Shelly(host)

    # Name of the script is just the basename.
    name = os.path.basename(file)

    # Uploading is via a script ID. Fetch or create an ID.
    scripts = list_scripts(shelly)
    print('EXISTING:', scripts)
    if not (sid := scripts.get(name)):
        sid = create_script(shelly, name)
    print('SID:', sid)
    
    # Slurp in the entire script.
    code = open(args.file, mode='r', encoding='utf-8').read()

    pos = 0
    append = False
    while pos < len(code):
        chunk = code[pos : pos+CHUNK_SIZE]
        r = shelly.call('Script.PutCode', id=sid, code=chunk, append=append)
        print(f'CHUNK: pos:{pos}  RESULT:{r}')

        pos += CHUNK_SIZE
        append = True


def list_scripts(shelly):
    j = shelly.call('Script.List')
    return dict((s['name'], s['id']) for s in j['scripts'])


def create_script(shelly, file):
    j = shelly.call('Script.Create', name=file)
    print('CREATED:', j)
    return j['id']


class Shelly:
    def __init__(self, host):
        self.session = requests.Session()
        self.host = host

    def call(self, rpc, **params):
        url = f'http://{self.host}/rpc/{rpc}'
        body = json.dumps(params, ensure_ascii=False)
        r = self.session.post(url, data=body.encode('utf-8'))
        return r.json()


def call(rpc, rest):
    params = dict(arg.split('=', maxsplit=1) for arg in rest)
    print('PARAMS:', params)
    shelly = Shelly(args.host)
    print(shelly.call(args.rpc, **params))


if __name__ == '__main__':
    script = os.path.basename(sys.argv[0])
    UPLOAD = (script == 'upload.py')
    assert UPLOAD or (script == 'call.py')

    parser = argparse.ArgumentParser()
    parser.add_argument('host',
                        help='IP or hostname of the Shelly device')
    if UPLOAD:
        parser.add_argument('file',
                            help='Filename of script to upload')
    else:
        parser.add_argument('rpc',
                            help='RPC method to call')
    if UPLOAD:
        args = parser.parse_args()
        upload(args.host, args.file)
    else:
        args, rest = parser.parse_known_args()
        call(args.host, rest)