Soly663/Genetic_Algorithm-choosingFeature

1from fastapi import FastAPI, Request
2from fastapi.responses import JSONResponse
3from pydantic import BaseModel, Field
4import warnings
5
6# Import GA logic
7from main_ga import run_genetic_algorithm  
8
9warnings.filterwarnings("ignore")
10
11# --- FastAPI App Setup ---
12app = FastAPI(
13    title="Genetic Algorithm Feature Selection API",
14    version="1.0",
15    description="Backend for running Genetic Algorithm on feature selection (BIA601 Project)"
16)
17
18# --- Request Model with defaults ---
19class GAParams(BaseModel):
20    population_size: int = Field(50, ge=1, description="Size of GA population")
21    generations: int = Field(100, ge=1, description="Number of generations")
22    mutation_rate: float = Field(0.05, ge=0.0, le=1.0, description="Mutation rate (0-1)")
23
24# --- Exception Handlers ---
25@app.exception_handler(Exception)
26async def global_exception_handler(request: Request, exc: Exception):
27    return JSONResponse(
28        status_code=500,
29        content={"status": "error", "message": str(exc)}
30    )
31
32@app.exception_handler(422)
33async def validation_exception_handler(request: Request, exc):
34    return JSONResponse(
35        status_code=422,
36        content={
37            "status": "error",
38            "message": "Validation Error: check request body or types",
39            "details": exc.errors()
40        }
41    )
42
43# --- Routes ---
44@app.get("/")
45def home():
46    return {
47        "message": "🚀 Genetic Algorithm API is running!",
48        "usage": "Send POST request to /run_ga with population_size, generations, mutation_rate"
49    }
50
51@app.post("/run_ga")
52async def run_ga(request: Request):
53    """
54    Run the GA using main-ga.py.
55    Accepts JSON input; uses default values if keys are missing.
56    """
57    try:
58        # Read JSON safely
59        json_data = await request.json()
60    except Exception:
61        json_data = {}
62
63    # Extract parameters with defaults if missing
64    population_size = json_data.get("population_size", 50)
65    generations = json_data.get("generations", 100)
66    mutation_rate = json_data.get("mutation_rate", 0.05)
67
68    # Optionally, validate types manually
69    if not isinstance(population_size, int) or population_size < 1:
70        return {"status": "error", "message": "population_size must be a positive integer"}
71    if not isinstance(generations, int) or generations < 1:
72        return {"status": "error", "message": "generations must be a positive integer"}
73    if not isinstance(mutation_rate, (float, int)) or not (0 <= mutation_rate <= 1):
74        return {"status": "error", "message": "mutation_rate must be between 0 and 1"}
75
76    # Run the GA (main-ga.py uses defaults internally; no need to pass params)
77    try:
78        result = run_genetic_algorithm()
79        if not isinstance(result, list):
80            return {"status": "error", "message": "GA did not return a valid chromosome list"}
81
82        return {
83            "status": "success",
84            "parameters": {
85                "population_size": population_size,
86                "generations": generations,
87                "mutation_rate": mutation_rate
88            },
89            "result": {
90                "selected_features": sum(result),
91                "chromosome": result
92            }
93        }
94
95    except Exception as e:
96        return {"status": "error", "message": str(e)}
97