Модули для обработки http-запросов, базовый обработчик url-путей. Обертка для работы с shelve базами данных, html-шаблонизатор.

1 files changed, 180 insertions, 0 deletions

diff --git a/day7/backend.py b/day7/backend.py
new file mode 100644
index 0000000..9f9b118
--- /dev/null
+++ b/day7/backend.py
@@ -0,0 +1,180 @@
+import re
+
+from templater import render_template
+from utils import parse_cookies, add_headers, SUCCESS, BAD_REQUEST, NOT_FOUND
+from config import TEXT_TEMPLATE_NAME
+import db
+
+
+_router_tree = {}
+
+
+# url_format - регулярное выражение
+def route(url_format, methods=None):
+    if methods is None:
+        methods = ['GET']
+
+    def wrapper(func):
+        def inner(url, query, *args, **kwargs):
+            pattern = re.compile(url_format)
+            match = re.match(pattern, url)
+
+            if match is None or len(match.groups()) != pattern.groups:
+                return BAD_REQUEST, '400 BAD REQUEST'
+
+            return func(query, *match.groups(), *args, **kwargs)
+
+        _router_tree[url_format] = _router_tree.get(url_format, {})
+        for method in methods:
+            _router_tree[url_format][method] = inner
+
+        return inner
+
+    return wrapper
+
+
+def run(method, url: str, cookies: dict, query):
+    res = NOT_FOUND, NOT_FOUND + 'KAVO'
+    for key, value in cookies.items():
+        db.set_cookie(key, value)
+
+    for url_pattern in _router_tree:
+        if re.fullmatch(url_pattern, url) and method in _router_tree[url_pattern]:
+            res = _router_tree[url_pattern][method](url, query)
+
+    return add_headers(*res)
+
+
+@route('/')
+def index_get(query, *args):
+    return SUCCESS, render_template('form', color=get_color())
+
+
+@route('/', ['POST'])
+def index_post(query, *args):
+    return SUCCESS, str(query)
+
+# Хотелось попробовать сделать что-то высокоуровневое с декораторами.
+# Если в этом коде есть какие-то серьезные проблемы, то скажите сразу.
+@route(r'/div/(\d+)/to/(\d+)/?')
+def divide_get(query, *args):
+    color = get_color()
+
+    try:
+        text = str(int(args[0]) / int(args[1]))
+        return SUCCESS, render_template(TEXT_TEMPLATE_NAME, text=text, color=color)
+
+    except ZeroDivisionError as e:
+        return BAD_REQUEST, render_template(
+            TEXT_TEMPLATE_NAME, color=color,
+            text=BAD_REQUEST + ('<br>' + str(e) if db.get_config_entry('show_errors') else '')
+        )
+
+
+@route(r'/div/?', ['POST'])
+def divide_post(query, *args):
+    color = get_color()
+
+    try:
+        text = str(int(query['numerator']) / int(query['denominator']))
+        return SUCCESS, render_template(TEXT_TEMPLATE_NAME, text=text, color=color)
+
+    except KeyError:
+        field = 'числитель' if 'numerator' not in query else 'знаменатель'
+        return BAD_REQUEST, render_template(
+            TEXT_TEMPLATE_NAME, color=color,
+            text=BAD_REQUEST + ('<br>' + f'Указан неверный {field}')
+        )
+
+    except (ValueError, ZeroDivisionError) as e:
+        return BAD_REQUEST, render_template(
+            TEXT_TEMPLATE_NAME, color=color,
+            text=BAD_REQUEST + ('<br>' + str(e) if db.get_config_entry('show_errors') else '')
+        )
+
+
+@route(r'/show_errors/(\d{1})/?')
+def show_errors_get(query, *args):
+    color = get_color()
+
+    if args[0] == '1':
+        db.set_config_entry('show_errors', 1)
+        return SUCCESS, render_template(TEXT_TEMPLATE_NAME, color=color, text='Опция show_errors включена')
+
+    elif args[0] == '0':
+        db.set_config_entry('show_errors', 0)
+        return SUCCESS, render_template(TEXT_TEMPLATE_NAME, color=color, text='Опция show_errors выключена')
+
+    else:
+        return BAD_REQUEST, render_template(
+            TEXT_TEMPLATE_NAME, color=color,
+            text='Опция show_errors не может принимать такое значение'
+        )
+
+
+@route(r'/show_errors/?', ['POST'])
+def show_errors_post(query, *args):
+    color = get_color()
+
+    if 'show_errors' not in query:
+        db.set_config_entry('show_errors', 0)
+        return SUCCESS, render_template(TEXT_TEMPLATE_NAME, color=color, text='Опция show_errors выключена')
+
+    elif query['show_errors'] == '1':
+        db.set_config_entry('show_errors', 1)
+        return SUCCESS, render_template(TEXT_TEMPLATE_NAME, color=color, text='Опция show_errors включена')
+
+    else:
+        return BAD_REQUEST, render_template(
+            TEXT_TEMPLATE_NAME, color=color,
+            text='Опция show_errors не может принимать такое значение'
+        )
+
+
+@route(r'/set_cookie/=/(.*)/?')
+def set_cookie_get(query, *args):
+    cookie_line = args[0]
+    color = get_color()
+    try:
+        cookies = parse_cookies(cookie_line)
+        for key, value in cookies.items():
+            db.set_cookie(key, value)
+
+        return SUCCESS, render_template(TEXT_TEMPLATE_NAME, color=color, text='Cookie-файл обновлен')
+
+    except ValueError as e:
+        return BAD_REQUEST, render_template(
+            TEXT_TEMPLATE_NAME, color=color,
+            text=BAD_REQUEST + ('<br>' + str(e) if db.get_config_entry('show_errors') else '')
+        )
+
+
+@route(r'/set_cookie/=/?', ['POST'])
+def set_cookie_post(query, *args):
+    color = get_color()
+    try:
+        cookie_line = query['cookie_line']
+        cookies = parse_cookies(cookie_line)
+        for key, value in cookies.items():
+            db.set_cookie(key, value)
+
+        return SUCCESS, render_template(TEXT_TEMPLATE_NAME, color=color, text='Cookie-файл обновлен')
+
+    except KeyError:
+        return BAD_REQUEST, render_template(
+            TEXT_TEMPLATE_NAME, color=color,
+            text=BAD_REQUEST + ('<br>' + f'Не указана строка с cookie')
+        )
+
+    except ValueError as e:
+        return BAD_REQUEST, render_template(
+            TEXT_TEMPLATE_NAME, color=color,
+            text=BAD_REQUEST + ('<br>' + str(e) if db.get_config_entry('show_errors') else '')
+        )
+
+
+def get_color():
+    color = db.get_cookie('bg_color', 'white')
+    if color not in ['green', 'white']:
+        color = 'white'
+    return color