Refactor services and unify backend–bot integration

- Switched to async processing in `SolverService` with method selection logic
- Reorganized `ApplicationProcessingService` for clearer async flow
- Introduced `NotFoundException` for missing resources
- Replaced `SolverException` where appropriate
- Added centralized exception handling in `GlobalExceptionHandler`
- Updated routing in `SolverController`, including parameter types (e.g. `Integer → Long`)
- Improved logging and error responses
- Changed column types and added constraints in `schema.sql`
- Updated `DBService` queries for history filtering and limiting
- Adjusted `Dockerfile`, versioning, and jar paths
- Made log directory path relative in `logback-spring.xml`
- Synced API usage with updated backend routes and parameters
- Minor formatting/styling improvements

Author: dmitryesin

database/schema.sql

@@ -1,23 +1,23 @@
-create Table users (
-    id INT PRIMARY KEY NOT NULL,
-    method VARCHAR(25) NOT NULL,
-    rounding VARCHAR(2) NOT NULL,
-    language VARCHAR(2) NOT NULL,
+CREATE TABLE users (
+    id BIGINT PRIMARY KEY,
+    method TEXT NOT NULL,
+    rounding SMALLINT NOT NULL,
+    language TEXT NOT NULL,
     hints BOOLEAN NOT NULL
 );
 
 CREATE TABLE applications (
     id SERIAL PRIMARY KEY,
-    user_id INTEGER REFERENCES users(id) ON DELETE SET NULL,
+    user_id BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
     parameters JSONB NOT NULL,
-    status TEXT NOT NULL CHECK (status IN ('new', 'in_progress', 'completed', 'error')),
+    status TEXT NOT NULL,
     created_at TIMESTAMP NOT NULL DEFAULT NOW(),
     last_updated_at TIMESTAMP NOT NULL DEFAULT NOW()
 );
 
 CREATE TABLE results (
     id SERIAL PRIMARY KEY,
-    application_id INTEGER NOT NULL REFERENCES applications(id) ON DELETE CASCADE,
+    application_id INT NOT NULL REFERENCES applications(id) ON DELETE CASCADE,
     data JSONB NOT NULL,
     created_at TIMESTAMP NOT NULL DEFAULT NOW()
 );

docker-compose.yml

@@ -8,12 +8,10 @@ services:
     env_file:
       - .env
     environment:
-      - CLIENT_API_KEY=${CLIENT_API_KEY}
       - CLIENT_API_URL=http://server:8080/api/solver
     ports:
       - "8001:8000"
     volumes:
-      - ./solver-bot/src:/solver-client/src
       - .env:/solver-client/.env
     depends_on:
       - database
@@ -30,16 +28,10 @@ services:
     env_file:
       - .env
     environment:
-      - DB_CONNECTION=${DB_CONNECTION}
       - DB_HOST=database
-      - DB_PORT=${DB_PORT}
-      - DB_DATABASE=${DB_DATABASE}
-      - DB_USERNAME=${DB_USERNAME}
-      - DB_PASSWORD=${DB_PASSWORD}
     ports:
       - "8081:8080"
     volumes:
-      - ./solver-common/src:/solver-server/src
       - .env:/solver-server/.env
     depends_on:
       - database

solver-bot/src/main/python/equation/equation_parser.py

@@ -3,6 +3,7 @@
 
 from equation.function_replacer import replace_math_functions
 
+
 def get_equation_order(eq):
     derivatives = list(eq.lhs.atoms(sp.Derivative))
     if not derivatives:
@@ -16,20 +17,20 @@ def convert_to_first_order(eq, y, x):
     if order == 0:
         return eq, order
 
-    y_vars = [sp.Symbol(f'y[{i}]') for i in range(order)]
+    y_vars = [sp.Symbol(f"y[{i}]") for i in range(order)]
     subs_dict = {y.diff(x, i): y_vars[i] for i in range(order)}
     subs_dict[y] = y_vars[0]
 
     last_derivative = y.diff(x, order)
     last_eq = sp.solve(eq, last_derivative)[0].subs(subs_dict)
-    last_equation = sp.Eq(sp.Symbol(f'y[{order - 1}]').diff(x), last_eq)
+    last_equation = sp.Eq(sp.Symbol(f"y[{order - 1}]").diff(x), last_eq)
 
     return last_equation, order
 
 
 def parse_equation(eq):
-    x = sp.Symbol('x')
-    y = sp.Function('y')(x)
+    x = sp.Symbol("x")
+    y = sp.Function("y")(x)
 
     eq = eq.replace(" ", "").replace("`", "'").replace("’", "'")
     eq = re.sub(r"y\^\((\d+)\)", lambda m: "y" + "'" * int(m.group(1)), eq)

solver-bot/src/main/python/equation/equation_validator.py

@@ -11,24 +11,27 @@
 
 
 def validate_symbols(equation):
-    allowed_vars = {'x', 'y', 'X', 'Y'}
-    symbols = re.findall(r'[a-zA-Z]+|\d+|\S', equation)
+    allowed_vars = {"x", "y", "X", "Y"}
+    symbols = re.findall(r"[a-zA-Z]+|\d+|\S", equation)
     for symbol in symbols:
-        if symbol.isalpha() and symbol not in allowed_vars and symbol not in MATH_FUNCTIONS:
+        if (
+            symbol.isalpha()
+            and symbol not in allowed_vars
+            and symbol not in MATH_FUNCTIONS
+        ):
             return False, symbol
     return True, None
 
 
 def validate_parentheses(equation):
     stack = []
     for i, char in enumerate(equation):
-        if char == '(':
+        if char == "(":
             stack.append(i)
-        elif char == ')':
+        elif char == ")":
             if not stack:
                 return False
             start_index = stack.pop()
-            # Check for empty parentheses
             if start_index + 1 == i:
                 return False
 

solver-bot/src/main/python/equation/function_replacer.py

@@ -17,17 +17,11 @@ def replace_math_functions(equation):
     if there are, it converts them.
     """
     for func, replacement in MATH_FUNCTIONS.items():
-        if func in ['coth', 'cth']:
-            equation = re.sub(rf'\b{func}\((.*?)\)',
-                              r'(cosh(\1) / sinh(\1))',
-                              equation)
-        elif func in ['acot', 'actg', 'arccot', 'arcctg']:
-            equation = re.sub(rf'\b{func}\((.*?)\)',
-                              r'(atan(1 / \1))',
-                              equation)
+        if func in ["coth", "cth"]:
+            equation = re.sub(rf"\b{func}\((.*?)\)", r"(cosh(\1) / sinh(\1))", equation)
+        elif func in ["acot", "actg", "arccot", "arcctg"]:
+            equation = re.sub(rf"\b{func}\((.*?)\)", r"(atan(1 / \1))", equation)
         else:
-            equation = re.sub(rf'\b{func}\b',
-                              f'{replacement}',
-                              equation)
+            equation = re.sub(rf"\b{func}\b", f"{replacement}", equation)
 
     return equation

solver-bot/src/main/python/languages.json

@@ -27,12 +27,14 @@
 
         "hints_text": "Hint:",
 
-        "hints_enter_equation": "For example: y' = x + y or y'' + sin(x). You can use variables x and y, arithmetic operators (+, -, *, /), and functions such as sin(x), exp(x), ln(x).",
-        "hints_enter_x": "The point at which you start solving. For example, if you want to solve the equation with the initial value y(0) = 1, enter 0.",
-        "hints_enter_y": "The initial value of the function y at the given x. For example, if you want to solve the equation with the initial value y(0) = 1, enter 1.",
-        "hints_enter_y_multiple": "Initial values of the function y at the given x values. For example, if you want to solve the equation with initial values y(0) = 1 and y(1) = 2, enter 1, 2 or 1 2.",
-        "hints_enter_reach_point": "Specifies up to which point you want to solve the equation. For example, if you want to solve the equation up to x = 10, enter 10.",
-        "hints_enter_step_size": "Affects the calculation accuracy. For example: if you want the step size to be 0.1, enter 0.1.",
+        "hints": {
+            "enter_equation": "For example: y' = x + y or y'' + sin(x). You can use variables x and y, arithmetic operators (+, -, *, /), and functions such as sin(x), exp(x), ln(x).",
+            "enter_x": "The point at which you start solving. For example, if you want to solve the equation with the initial value y(0) = 1, enter 0.",
+            "enter_y": "The initial value of the function y at the given x. For example, if you want to solve the equation with the initial value y(0) = 1, enter 1.",
+            "enter_y_multiple": "Initial values of the function y at the given x values. For example, if you want to solve the equation with initial values y(0) = 1 and y(1) = 2, enter 1, 2 or 1 2.",
+            "enter_reach_point": "Specifies up to which point you want to solve the equation. For example, if you want to solve the equation up to x = 10, enter 10.",
+            "enter_step_size": "Affects the calculation accuracy. For example: if you want the step size to be 0.1, enter 0.1."
+        },
 
         "equation_error": "The equation is incorrect.",
         "symbols_error": "The equation contains invalid symbols: ",
@@ -42,10 +44,11 @@
         "invalid_initial_y_count1": "Invalid number of initial y values: ",
         "invalid_initial_y_count2": "Expected: ",
         "invalid_reach_point": "Invalid approximation point.",
+        "reach_point_equals_initial": "The approximation point must be different from the initial x value.",
         "invalid_step_size": "Invalid step size value.",
+        "too_many_points": "Too many calculation points: ",
+        "max_points_allowed": "Maximum allowed: ",
 
-        "processing": "Processing your request...",
-        "processing_longer": "It may take longer than usual to process your request. Please wait...",
         "processing_error": "Error processing your request.",
         "data_error": "The entered data is incorrect.",
         "server_error": "Server error.",
@@ -98,12 +101,14 @@
 
         "hints_text": "Подсказка:",
 
-        "hints_enter_equation": "Например: y' = x + y или y'' + sin(x). Можно использовать переменные x и y, арифметические знаки (+, -, *, /) и функции, такие как sin(x), exp(x), ln(x).",
-        "hints_enter_x": "Точка, в которой вы начинаете решение. Например, если вы хотите решить уравнение с начальным значением y(0) = 1, введите 0.",
-        "hints_enter_y": "Начальное значение функции y при заданном x. Например, если вы хотите решить уравнение с начальным значением y(0) = 1, введите 1.",
-        "hints_enter_y_multiple": "Начальные значения функции y при заданных x. Например, если вы хотите решить уравнение с начальными значениями y(0) = 1 и y(1) = 2, введите 1, 2 или 1 2.",
-        "hints_enter_reach_point": "Определяет, до какой точки вы хотите решить уравнение. Например, если вы хотите решить уравнение до x = 10, введите 10.",
-        "hints_enter_step_size": "Влияет на точность вычислений. Например: если вы хотите, чтобы шаг был 0.1, введите 0.1.",
+        "hints": {
+            "enter_equation": "Например: y' = x + y или y'' + sin(x). Можно использовать переменные x и y, арифметические знаки (+, -, *, /) и функции, такие как sin(x), exp(x), ln(x).",
+            "enter_x": "Точка, в которой вы начинаете решение. Например, если вы хотите решить уравнение с начальным значением y(0) = 1, введите 0.",
+            "enter_y": "Начальное значение функции y при заданном x. Например, если вы хотите решить уравнение с начальным значением y(0) = 1, введите 1.",
+            "enter_y_multiple": "Начальные значения функции y при заданных x. Например, если вы хотите решить уравнение с начальными значениями y(0) = 1 и y(1) = 2, введите 1, 2 или 1 2.",
+            "enter_reach_point": "Определяет, до какой точки вы хотите решить уравнение. Например, если вы хотите решить уравнение до x = 10, введите 10.",
+            "enter_step_size": "Влияет на точность вычислений. Например: если вы хотите, чтобы шаг был 0.1, введите 0.1."
+        },
 
         "equation_error": "Уравнение некорректно.",
         "symbols_error": "Уравнение содержит недопустимые символы: ",
@@ -113,10 +118,11 @@
         "invalid_initial_y_count1": "Некорректное количество начальных значений y: ",
         "invalid_initial_y_count2": "Ожидалось: ",
         "invalid_reach_point": "Некорректное значение точки аппроксимации.",
+        "reach_point_equals_initial": "Точка аппроксимации должна отличаться от начального значения x.",
         "invalid_step_size": "Некорректное значение размера шага.",
+        "too_many_points": "Слишком много точек для вычисления: ",
+        "max_points_allowed": "Максимально допустимо: ",
 
-        "processing": "Обработка вашего запроса...",
-        "processing_longer": "Обработка вашего запроса может занять больше времени, чем обычно. Пожалуйста, подождите...",
         "processing_error": "Ошибка при обработке вашего запроса.",
         "data_error": "Введенные данные некорректны.",
         "server_error": "Ошибка сервера.",
@@ -169,12 +175,14 @@
 
         "hints_text": "提示：",
 
-        "hints_enter_equation": "例如：y' = x + y 或 y'' + sin(x)。您可以使用变量 x 和 y，算术运算符（+、-、*、/），以及 sin(x)、exp(x)、ln(x) 等函数。",
-        "hints_enter_x": "开始求解的点。例如，如果您想求解初值 y(0) = 1 的方程，输入 0。",
-        "hints_enter_y": "在给定 x 处函数 y 的初值。例如，如果您想求解初值 y(0) = 1 的方程，输入 1。",
-        "hints_enter_y_multiple": "在给定 x 值处函数 y 的初值。例如，如果您想求解初值 y(0) = 1 和 y(1) = 2 的方程，输入 1, 2 或 1 2。",
-        "hints_enter_reach_point": "指定要解方程到的点。例如，如果您想解方程到 x = 10，输入 10。",
-        "hints_enter_step_size": "影响计算精度。例如：如果您希望步长为 0.1，输入 0.1。",
+        "hints": {
+            "enter_equation": "例如：y' = x + y 或 y'' + sin(x)。您可以使用变量 x 和 y，算术运算符（+、-、*、/），以及 sin(x)、exp(x)、ln(x) 等函数。",
+            "enter_x": "开始求解的点。例如，如果您想求解初值 y(0) = 1 的方程，输入 0。",
+            "enter_y": "在给定 x 处函数 y 的初值。例如，如果您想求解初值 y(0) = 1 的方程，输入 1。",
+            "enter_y_multiple": "在给定 x 值处函数 y 的初值。例如，如果您想求解初值 y(0) = 1 和 y(1) = 2 的方程，输入 1, 2 或 1 2。",
+            "enter_reach_point": "指定要解方程到的点。例如，如果您想解方程到 x = 10，输入 10。",
+            "enter_step_size": "影响计算精度。例如：如果您希望步长为 0.1，输入 0.1。"
+        },
 
         "equation_error": "方程不正确。",
         "symbols_error": "方程包含无效符号：",
@@ -184,10 +192,11 @@
         "invalid_initial_y_count1": "初始y值数量无效：",
         "invalid_initial_y_count2": "应为：",
         "invalid_reach_point": "无效的近似点。",
+        "reach_point_equals_initial": "近似点必须与初始x值不同。",
         "invalid_step_size": "无效的步长值。",
+        "too_many_points": "计算点数过多：",
+        "max_points_allowed": "最大允许：",
 
-        "processing": "正在处理您的请求...",
-        "processing_longer": "处理时间可能较长，请稍候...",
         "processing_error": "处理请求时出错。",
         "data_error": "输入数据不正确。",
         "server_error": "服务器错误。",

solver-bot/src/main/python/logger.py

@@ -6,14 +6,13 @@
 LOGS_DIR.mkdir(parents=True, exist_ok=True)
 
 formatter = logging.Formatter(
-    "%(asctime)s - %(levelname)s - %(name)s - %(message)s",
-    datefmt="%Y-%m-%d %H:%M:%S"
+    "%(asctime)s - %(levelname)s - %(name)s - %(message)s", datefmt="%Y-%m-%d %H:%M:%S"
 )
 
 console_handler = logging.StreamHandler()
 console_handler.setFormatter(formatter)
 
-file_handler = logging.FileHandler(LOGS_DIR / "solver-bot.log", encoding='utf-8')
+file_handler = logging.FileHandler(LOGS_DIR / "solver-bot.log", encoding="utf-8")
 file_handler.setFormatter(formatter)
 
 logging.basicConfig(level=logging.INFO, handlers=[console_handler, file_handler])

solver-bot/src/main/python/plotting/plotter.py

@@ -3,24 +3,26 @@
 
 from printing.printer import get_variable_name
 
-def plot_solution(x_values, y_values, order):
-    plt.clf()
 
+def plot_solution(x_values, y_values, order):
     plt.figure(figsize=(10, 6), dpi=200)
-
     plt.grid(True)
 
     variable_names = ["y"] + [get_variable_name(i) for i in range(1, order)]
 
-    plt.plot(x_values, y_values, label=variable_names)
+    is_multivariable = isinstance(y_values[0], (list, tuple))
+
+    if is_multivariable:
+        for i, var_name in enumerate(variable_names):
+            plt.plot(x_values, [y[i] for y in y_values], label=var_name)
+    else:
+        plt.plot(x_values, y_values, label=variable_names[0])
 
     plt.legend()
 
     buffer = io.BytesIO()
-    plt.savefig(buffer, format='png', bbox_inches="tight")
-
+    plt.savefig(buffer, format="png", bbox_inches="tight")
     plt.close()
-
     buffer.seek(0)
 
     return buffer

solver-bot/src/main/python/printing/printer.py

@@ -6,22 +6,27 @@ def get_variable_name(i):
     if i < 4:
         return f"y{chr(39) * i}"
     else:
-        return "y⁽" + ''.join(superscripts[int(d)] for d in str(i)) + "⁾"
+        return "y⁽" + "".join(superscripts[int(d)] for d in str(i)) + "⁾"
 
 
 def print_solution(result, order, rounding):
     def format_value(value):
         formatted_value = f"{value:.{rounding}f}"
-        if '.' in formatted_value:
-            formatted_value = formatted_value.rstrip('0')
-            if formatted_value.endswith('.'):
-                formatted_value += '0'
+        if "." in formatted_value:
+            formatted_value = formatted_value.rstrip("0")
+            if formatted_value.endswith("."):
+                formatted_value += "0"
         return formatted_value
 
     variable_names = [get_variable_name(i) for i in range(order)]
-    values = [format_value(result[i]) if i < len(result) else "NaN" for i in range(1, order + 1)]
+    values = [
+        format_value(result[i]) if i < len(result) else "NaN"
+        for i in range(1, order + 1)
+    ]
 
     formatted_x = format_value(result[0])
-    variables_str = ", ".join(f"{name}: {val}" for name, val in zip(variable_names, values))
+    variables_str = ", ".join(
+        f"{name}: {val}" for name, val in zip(variable_names, values)
+    )
 
     return f"x: {formatted_x}, {variables_str}"