from datetime import datetime

from flask import Flask, render_template
from flask_sqlalchemy import SQLAlchemy
from flask_wtf import CSRFProtect
from markupsafe import Markup

from config import Config

db = SQLAlchemy()
csrf = CSRFProtect()


class Section(db.Model):
    __tablename__ = "section"
    id = db.Column(db.Integer, primary_key=True)
    num = db.Column(db.Integer, nullable=False, unique=True)
    title = db.Column(db.String(160), nullable=False)
    subtitle = db.Column(db.String(255))
    sort_order = db.Column(db.Integer, nullable=False, default=0)
    topics = db.relationship(
        "Topic",
        backref="section",
        order_by="Topic.sort_order",
        cascade="all, delete-orphan",
    )


class Topic(db.Model):
    __tablename__ = "topic"
    id = db.Column(db.Integer, primary_key=True)
    section_id = db.Column(
        db.Integer, db.ForeignKey("section.id", ondelete="CASCADE"), nullable=False
    )
    slug = db.Column(db.String(80), nullable=False, unique=True)
    title = db.Column(db.String(200), nullable=False)
    body_html = db.Column(db.Text)
    link_url = db.Column(db.String(500))
    link_label = db.Column(db.String(120))
    media_type = db.Column(db.String(16), nullable=False, default="none")
    media_url = db.Column(db.String(500))
    media_caption = db.Column(db.String(255))
    sort_order = db.Column(db.Integer, nullable=False, default=0)

    @property
    def body(self):
        # Content is admin-authored and trusted; render as-is.
        return Markup(self.body_html or "")

    @property
    def is_youtube(self):
        u = (self.media_url or "").lower()
        return "youtube.com" in u or "youtu.be" in u


class AuditLog(db.Model):
    __tablename__ = "audit_log"
    id = db.Column(db.Integer, primary_key=True)
    actor = db.Column(db.String(80))
    action = db.Column(db.String(40), nullable=False)      # create / update / delete
    entity = db.Column(db.String(40), nullable=False)      # section / topic
    entity_id = db.Column(db.Integer)
    detail = db.Column(db.String(255))
    created_at = db.Column(db.DateTime, nullable=False, default=datetime.utcnow)


def log_action(actor, action, entity, entity_id=None, detail=None):
    """Record an audit row. MUST be called AFTER db.session.commit() of the
    change it describes, so a failed transaction never leaves an orphan log."""
    entry = AuditLog(
        actor=actor, action=action, entity=entity,
        entity_id=entity_id, detail=detail,
    )
    db.session.add(entry)
    db.session.commit()


def create_app():
    app = Flask(__name__)
    app.config.from_object(Config)
    db.init_app(app)
    csrf.init_app(app)

    # Deferred import avoids a circular import: admin.py imports the models and
    # log_action defined above, which are ready by the time create_app() runs.
    from admin import admin_bp
    app.register_blueprint(admin_bp)

    @app.route("/")
    def index():
        sections = (
            Section.query.order_by(Section.sort_order, Section.num).all()
        )
        return render_template(
            "index.html",
            sections=sections,
            demo_url=app.config["DEMO_CONTACT_URL"],
        )

    @app.route("/healthz")
    def healthz():
        return {"status": "ok"}

    return app


app = create_app()


if __name__ == "__main__":
    app.run(host="127.0.0.1", port=8000, debug=True)