app.py

from __future__ import annotations

import uuid
from pathlib import Path

from flask import Flask, abort, redirect, render_template, request, send_from_directory, url_for
from werkzeug.utils import secure_filename

from tracker import TrackingError, process_video


BASE_DIR = Path(__file__).resolve().parent
UPLOAD_DIR = BASE_DIR / "static" / "uploads"
OUTPUT_DIR = BASE_DIR / "static" / "outputs"
ALLOWED_EXTENSIONS = {".mp4", ".avi", ".mov", ".mkv", ".webm"}
MAX_CONTENT_LENGTH = 500 * 1024 * 1024


app = Flask(__name__)
app.config["MAX_CONTENT_LENGTH"] = MAX_CONTENT_LENGTH

UPLOAD_DIR.mkdir(parents=True, exist_ok=True)
OUTPUT_DIR.mkdir(parents=True, exist_ok=True)


def allowed_file(filename: str) -> bool:
    return Path(filename).suffix.lower() in ALLOWED_EXTENSIONS


@app.get("/")
def index():
    return render_template("index.html")


@app.post("/upload")
def upload():
    file = request.files.get("video")
    if file is None or file.filename == "":
        return render_template("index.html", error="Select a video before running tracking."), 400

    if not allowed_file(file.filename):
        return (
            render_template(
                "index.html",
                error="Unsupported format. Upload MP4, AVI, MOV, MKV, or WebM.",
            ),
            400,
        )

    original_name = secure_filename(file.filename)
    upload_name = f"{Path(original_name).stem}_{uuid.uuid4().hex[:10]}{Path(original_name).suffix.lower()}"
    upload_path = UPLOAD_DIR / upload_name

    try:
        file.save(upload_path)
        output_path = Path(process_video(upload_path))
    except TrackingError as exc:
        return render_template("index.html", error=str(exc)), 500
    except Exception as exc:
        return render_template("index.html", error=f"Processing failed: {exc}"), 500

    return redirect(url_for("result", file=output_path.name))


@app.get("/result/")
def result():
    filename = request.args.get("file")
    if not filename:
        abort(404)

    output_path = OUTPUT_DIR / secure_filename(filename)
    if not output_path.exists():
        abort(404)

    return render_template(
        "result.html",
        video_url=url_for("static", filename=f"outputs/{output_path.name}"),
        download_url=url_for("download", filename=output_path.name),
        filename=output_path.name,
    )


@app.get("/download/")
def download():
    filename = request.args.get("filename") or request.args.get("file")
    if not filename:
        abort(404)

    safe_name = secure_filename(filename)
    output_path = OUTPUT_DIR / safe_name
    if not output_path.exists():
        abort(404)

    return send_from_directory(OUTPUT_DIR, safe_name, as_attachment=True)


@app.errorhandler(413)
def request_entity_too_large(_error):
    return render_template("index.html", error="File is too large. Maximum upload size is 500 MB."), 413


if __name__ == "__main__":
    app.run(host="0.0.0.0", port=5000, debug=False)