import os
from datetime import datetime, timezone

from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from dotenv import load_dotenv

load_dotenv()

db = SQLAlchemy()


def create_app():
    app = Flask(__name__)

    app.config["SECRET_KEY"] = os.getenv("SECRET_KEY", "dev-secret-change-me")
    app.config["SQLALCHEMY_DATABASE_URI"] = os.getenv(
        "DATABASE_URL",
        "postgresql://photohost:photohost_secret@localhost:5432/photohost",
    )
    app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False
    app.config["UPLOAD_FOLDER"] = os.getenv("UPLOAD_FOLDER", "uploads")
    app.config["MAX_CONTENT_LENGTH"] = int(os.getenv("MAX_UPLOAD_MB", "10")) * 1024 * 1024
    app.config["ALLOWED_EXTENSIONS"] = {"png", "jpg", "jpeg", "gif", "webp", "bmp"}

    os.makedirs(app.config["UPLOAD_FOLDER"], exist_ok=True)

    db.init_app(app)

    from .routes import bp

    app.register_blueprint(bp)

    with app.app_context():
        db.create_all()

    return app


class Photo(db.Model):
    __tablename__ = "photos"

    id = db.Column(db.Integer, primary_key=True)
    filename = db.Column(db.String(255), nullable=False)
    original_name = db.Column(db.String(255), nullable=False)
    file_size = db.Column(db.Integer, nullable=False, default=0)
    mime_type = db.Column(db.String(100), nullable=False, default="image/jpeg")
    created_at = db.Column(
        db.DateTime,
        nullable=False,
        default=lambda: datetime.now(timezone.utc),
    )

    @property
    def url(self):
        return f"/uploads/{self.filename}"

    @property
    def size_human(self):
        size = self.file_size
        for unit in ("Б", "КБ", "МБ", "ГБ"):
            if size < 1024:
                return f"{size:.0f} {unit}" if unit == "Б" else f"{size:.1f} {unit}"
            size /= 1024
        return f"{size:.1f} ТБ"