from fastapi import FastAPI, HTTPException
from pydantic import BaseModel
from fastapi.middleware.cors import CORSMiddleware
import zlib

app = FastAPI(title="API PlantUML Encoder")

# Habilitar CORS para todos los orígenes
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],  # Permite todos los orígenes
    allow_credentials=True,
    allow_methods=["*"],  # Permite todos los métodos HTTP (GET, POST, PUT, DELETE, etc.)
    allow_headers=["*"],  # Permite todos los encabezados
)

class PlantUMLRequest(BaseModel):
    uml_code: str

@app.post("/generate-url/")
def generate_plantuml_url(request: PlantUMLRequest):
    try:
        encoded = encode_plantuml(request.uml_code)
        image_url = f"https://www.plantuml.com/plantuml/png/{encoded}"
        return {"image_url": image_url}
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

def encode_plantuml(plantuml_text):
    zlibbed_str = zlib.compress(plantuml_text.encode('utf-8'))
    compressed_string = zlibbed_str[2:-4]  # strip zlib headers
    return encode_base64(compressed_string)

def encode_base64(data):
    alphabet = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-_'
    result = ''
    data = bytearray(data)
    i = 0
    while i < len(data):
        b1 = data[i]
        b2 = data[i + 1] if i + 1 < len(data) else 0
        b3 = data[i + 2] if i + 2 < len(data) else 0
        result += alphabet[b1 >> 2]
        result += alphabet[((b1 & 0x3) << 4) | (b2 >> 4)]
        result += alphabet[((b2 & 0xF) << 2) | (b3 >> 6)]
        result += alphabet[b3 & 0x3F]
        i += 3
    return result