Add basic backend infrastructure

Signed-off-by: Felipe Cardoso <felipe.cardoso@hotmail.it>

backend/app/api/routes/samples.py

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+from typing import List
+
+from fastapi import APIRouter, HTTPException, Query
+
+from app.models.sample import Sample
+from app.services.sample_manager import SampleManager
+
+router = APIRouter()
+sample_manager = SampleManager()
+
+
+@router.get("/list", response_model=List[Sample])
+async def list_samples(
+        limit: int = Query(20, ge=1, le=100),
+        offset: int = Query(0, ge=0)
+):
+    """
+    List sample images with pagination
+    """
+    try:
+        return await sample_manager.list_samples(limit, offset)
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@router.get("/latest", response_model=List[Sample])
+async def get_latest_samples(count: int = Query(5, ge=1, le=20)):
+    """
+    Get the most recent sample images
+    """
+    try:
+        return await sample_manager.get_latest_samples(count)
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e))

backend/app/api/routes/training.py

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+from fastapi import APIRouter, HTTPException
+
+from app.models.training import TrainingStatus
+from app.services.training_monitor import TrainingMonitor
+
+router = APIRouter()
+monitor = TrainingMonitor()
+
+
+@router.get("/status", response_model=TrainingStatus)
+async def get_training_status():
+    """
+    Get current training status including progress, loss, and learning rate
+    """
+    try:
+        return await monitor.get_status()
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@router.get("/log")
+async def get_training_log():
+    """
+    Get recent training log entries
+    """
+    try:
+        return await monitor.get_log()
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e))

backend/app/core/config.py

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+from pydantic_settings import BaseSettings
+
+
+class Settings(BaseSettings):
+    # SFTP Settings
+    SFTP_HOST: str
+    SFTP_USER: str
+    SFTP_PASSWORD: str
+    SFTP_PATH: str
+    SFTP_PORT: int = 22
+
+    # API Settings
+    API_VER_STR: str = "/api/v1"
+    PROJECT_NAME: str = "Training Monitor"
+
+    class Config:
+        env_file = ".env"
+        case_sensitive = True
+
+
+settings = Settings()

backend/app/main.py

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+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+
+from app.api.routes import training, samples
+from app.core.config import settings
+
+app = FastAPI(
+    title="Training Monitor API",
+    description="API for monitoring ML training progress and samples",
+    version="1.0.0",
+)
+
+# Configure CORS
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],  # In production, replace with specific origins
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+# Include routers with versioning
+app.include_router(training.router, prefix=f"{settings.API_VER_STR}/training", tags=["training"])
+app.include_router(samples.router, prefix=f"{settings.API_VER_STR}/samples", tags=["samples"])
+
+
+@app.get("/health")
+async def health_check():
+    return {"status": "healthy"}

backend/app/models/sample.py

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+from datetime import datetime
+from typing import Optional
+
+from pydantic import BaseModel
+
+
+class Sample(BaseModel):
+    filename: str
+    url: str
+    created_at: datetime
+    step: Optional[int] = None

backend/app/models/training.py

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+from datetime import datetime
+from typing import Optional
+
+from pydantic import BaseModel
+
+
+class TrainingStatus(BaseModel):
+    current_step: int
+    total_steps: int
+    loss: float
+    learning_rate: float
+    eta_seconds: Optional[float]
+    steps_per_second: float
+    updated_at: datetime

backend/app/services/sample_manager.py

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+from typing import List
+
+from app.models.sample import Sample
+
+
+class SampleManager:
+    async def list_samples(self, limit: int, offset: int) -> List[Sample]:
+        # Implementation for listing samples from SFTP
+        # This is a placeholder - actual implementation needed
+        pass
+
+    async def get_latest_samples(self, count: int) -> List[Sample]:
+        # Implementation for getting latest samples
+        # This is a placeholder - actual implementation needed
+        pass

backend/app/services/training_monitor.py

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+from app.models.training import TrainingStatus
+
+
+class TrainingMonitor:
+    async def get_status(self) -> TrainingStatus:
+        # Implementation for parsing tqdm output
+        # This is a placeholder - actual implementation needed
+        pass
+
+    async def get_log(self):
+        # Implementation for getting recent log entries
+        # This is a placeholder - actual implementation needed
+        pass

backend/requirements.txt

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+fastapi>=0.104.0
+uvicorn>=0.24.0
+python-multipart>=0.0.6
+python-jose[cryptography]>=3.3.0
+passlib[bcrypt]>=1.7.4
+pydantic>=2.4.2
+pydantic-settings>=2.0.3
+paramiko>=3.3.1
+python-dotenv>=1.0.0
+aiofiles>=23.2.1
+pytest>=7.4.3
+httpx>=0.25.1
+pytest-asyncio>=0.21.1