Initial commit: HabitForge - habit tracking application with FastAPI backend, React frontend, and Zepp integration

backend/core/__init__.py

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+"""Core module for configuration and security."""

backend/core/config.py

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+"""Configuration module using pydantic_settings for environment-based configuration."""
+from secrets import token_urlsafe
+from typing import List, Union
+from pydantic import field_validator
+from pydantic_settings import BaseSettings, SettingsConfigDict
+
+
+class Settings(BaseSettings):
+    """Application settings loaded from environment variables."""
+
+    # Security
+    SECRET_KEY: str = token_urlsafe(32)
+    ALGORITHM: str = "HS256"
+    ACCESS_TOKEN_EXPIRE_MINUTES: int = 30
+
+    # Database
+    DATABASE_URL: str = "sqlite:///./data/habitforge.db"
+
+    # CORS
+    CORS_ORIGINS: Union[List[str], str] = ["http://localhost:8000", "http://localhost:3000"]
+    CORS_ALLOW_CREDENTIALS: bool = True
+    CORS_ALLOW_METHODS: Union[List[str], str] = ["*"]
+    CORS_ALLOW_HEADERS: Union[List[str], str] = ["*"]
+
+    # Google OAuth
+    GOOGLE_CLIENT_ID: str = ""
+    GOOGLE_CLIENT_SECRET: str = ""
+    GOOGLE_REDIRECT_URI: str = "http://localhost:8000/api/google/callback"
+
+    # Rate Limiting
+    RATE_LIMIT_ENABLED: bool = True
+    RATE_LIMIT_TIMES: int = 60
+    RATE_LIMIT_SECONDS: int = 60
+
+    # Application
+    APP_NAME: str = "HabitForge API"
+    APP_VERSION: str = "1.0.0"
+    DEBUG: bool = True
+    
+    # Health Data Provider Selection
+    # Options: "google_fit", "health_connect", "dual" (both for comparison)
+    HEALTH_PROVIDER: str = "google_fit"
+
+    @field_validator("CORS_ORIGINS", "CORS_ALLOW_METHODS", "CORS_ALLOW_HEADERS", mode="before")
+    @classmethod
+    def assemble_cors_list(cls, v: Union[str, List[str]]) -> List[str]:
+        """Convert a comma-separated string into a list of strings if necessary."""
+        if isinstance(v, str) and not v.startswith("["):
+            return [i.strip() for i in v.split(",") if i.strip()]
+        return v
+
+    model_config = SettingsConfigDict(
+        env_file=".env",
+        env_file_encoding="utf-8",
+        case_sensitive=True,
+        extra="ignore"
+    )
+
+
+# Global settings instance
+settings = Settings()