Add telegram-archiver microservice (MVP)

telegram-archiver/config.py

@@ -0,0 +1,87 @@
+"""
+Configuration management for Telegram Archiver.
+Uses pydantic-settings for .env file parsing and validation.
+"""
+
+from pydantic_settings import BaseSettings, SettingsConfigDict
+from pydantic import Field
+from pathlib import Path
+from typing import Optional
+
+
+class Settings(BaseSettings):
+    """Application settings loaded from environment variables and .env file."""
+
+    model_config = SettingsConfigDict(
+        env_file=".env",
+        env_file_encoding="utf-8",
+        case_sensitive=False,
+        extra="ignore",
+    )
+
+    # Telegram API credentials
+    api_id: int = Field(..., description="Telegram API ID from my.telegram.org")
+    api_hash: str = Field(..., description="Telegram API Hash from my.telegram.org")
+    phone: str = Field(..., description="Phone number for Telegram account")
+
+    # Session configuration
+    session_name: str = Field(
+        default="telegram-archiver",
+        description="Session name for Telethon (creates .session file)"
+    )
+
+    # File download limits
+    max_file_size: int = Field(
+        default=209715200,  # 200 MB
+        description="Maximum file size to download in bytes"
+    )
+
+    # Output configuration
+    output_dir: Path = Field(
+        default=Path("./archives"),
+        description="Directory to store archived channels"
+    )
+
+    # Logging configuration
+    log_level: str = Field(
+        default="INFO",
+        description="Logging level: DEBUG, INFO, WARNING, ERROR"
+    )
+
+    # OpenTelemetry (optional, for future)
+    otel_service_name: str = Field(
+        default="telegram-archiver",
+        description="Service name for OpenTelemetry traces"
+    )
+    otel_enabled: bool = Field(
+        default=False,
+        description="Enable OpenTelemetry tracing"
+    )
+
+    @property
+    def session_path(self) -> Path:
+        """Return full path to session file."""
+        return Path(__file__).parent / f"{self.session_name}.session"
+
+    def validate_credentials(self) -> bool:
+        """Validate that required credentials are present."""
+        if self.api_id <= 0:
+            raise ValueError("API_ID must be a positive integer")
+        if len(self.api_hash) < 10:
+            raise ValueError("API_HASH seems too short")
+        if not self.phone.startswith("+"):
+            raise ValueError("PHONE must start with +")
+        return True
+
+
+# Global settings instance
+settings: Optional[Settings] = None
+
+
+def get_settings() -> Settings:
+    """Get or create settings instance."""
+    global settings
+    if settings is None:
+        settings = Settings()
+        settings.validate_credentials()
+    return settings