from pathlib import Path

from fastapi import FastAPI, Response, status
from fastapi.responses import JSONResponse
from pydantic import BaseModel

app = FastAPI()
data_path = Path(__file__).parent.resolve() / "data"


class Files(BaseModel):
    files: list[str]


class Log(BaseModel):
    start: int
    size: int
    total: int
    content: str
    end: bool


class Error(BaseModel):
    error: str


@app.get("/", response_model=Files)
def list_logs():
    return {"files": [path.name for path in data_path.glob("*.txt") if path.is_file()]}


@app.get(
    "/log/{name}/",
    response_model=Log,
    responses={
        400: {"model": Error},
        404: {"model": Error},
    },
)
def get_log(name: str, start: int = 0, size: int = 100):
    path = data_path.joinpath(name)

    # Prevent path traversal
    if not path.is_relative_to(data_path):
        return JSONResponse(
            status_code=status.HTTP_400_BAD_REQUEST, content={"error": "Bad Request"}
        )

    if not path.is_file():
        return JSONResponse(
            status_code=status.HTTP_400_BAD_REQUEST, content={"error": "Log not found"}
        )

    with open(path) as f:
        f.seek(start)
        content = f.read(size)

    total = path.stat().st_size

    return {
        "start": start,
        "size": len(content),
        "total": total,
        "content": content,
        "end": size + start >= total,
    }