zulip/tools/get-handlebar-vars

#!/usr/bin/env python
from __future__ import print_function
import sys
import re
import json

from typing import Any, Dict, List

def debug(obj):
    print(json.dumps(obj, indent=4))

def parse_file(fn):
    # type: (str) -> Dict[str, Any]
    text = open(fn).read()
    tags = re.findall('{+\s*(.*?)\s*}+', text)
    root = {} # type: Dict[str, Any]
    context = root
    stack = [] # type: List[Dict[str, Any]]

    def set_var(var, val):
        # type: (str, Any) -> None
        num_levels_up = len(re.findall('\.\.', var))
        if num_levels_up:
            var = var.split('/')[-1]
            stack[-1 * num_levels_up][var] = val
        else:
            context[var] = val

    for tag in tags:
        if tag.startswith('! '):
            continue

        if tag == 'else':
            continue

        if tag[0] in '#^' and ' ' not in tag:
            var = tag[1:]
            set_var(var, True)
            stack.append(context)
            continue

        if tag.startswith('#if'):
            vars = tag.split()[1:]
            for var in vars:
                set_var(var, True)
            stack.append(context)
            continue

        if tag.startswith('/if'):
            context = stack.pop()
            continue

        if tag.startswith('#with '):
            var = tag.split()[1]
            new_context = {} # type: Dict[str, Any]
            context[var] = new_context
            stack.append(context)
            context = new_context
            continue

        if tag.startswith('/with'):
            context = stack.pop()
            continue

        if tag.startswith('#unless '):
            var = tag.split()[1]
            set_var(var, True)
            stack.append(context)
            continue

        if tag.startswith('/unless'):
            context = stack.pop()
            continue

        if tag.startswith('#each '):
            var = tag.split()[1]
            new_context = {}
            context[var] = [new_context]
            stack.append(context)
            context = new_context
            continue

        if tag.startswith('/each'):
            context = stack.pop()
            continue

        if tag.startswith('/'):
            context = stack.pop()
            continue

        set_var(tag, '')

    def clean_this(obj):
        # type: (Any) -> Any
        if isinstance(obj, list):
            return [clean_this(item) for item in obj]
        if isinstance(obj, dict):
            if len(obj) == 1 and 'this' in obj:
                return clean_this(obj['this'])
            return {k: clean_this(v) for k, v in obj.items()}
        return obj
    root = clean_this(root)
    return root

if __name__ == '__main__':
    for fn in sys.argv[1:]:
        print('===', fn)
        root = parse_file(fn)
        debug(root)
        print()