from flask import Response, render_template, request, redirect, url_for, session, g
from tinydb import where

from ttfrog import app, schema, forms

STATIC = ["static"]


def relative_uri(path: str = ""):
    """
    The request's URI relative to the VIEW_URI without the leading '/'.
    """

    return (path or request.path).replace(app.config.VIEW_URI, "", 1).strip("/") or "/"


def get_parent(table: str, uri: str):
    try:
        parent_uri = uri.strip("/").rsplit("/", 1)[0]
    except IndexError:
        return None

    return get_page(parent_uri, table=table if '/' in parent_uri else 'Page', create_okay=False)


def get_page(path: str = "", table: str = "Page", create_okay: bool = False):
    """
    Get one page, including its members, but not recursively.
    """
    uri = path.strip("/") or relative_uri(request.path)
    app.web.logger.debug(f"Need a page in {table} for {uri = }")
    if table not in app.db.tables():
        return None

    matches = app.db.table(table).search(where("uri") == uri, recurse=False)
    if not matches:
        if not create_okay:
            return None
        return getattr(schema, table)(
            name=uri.split("/")[-1],
            body="This page does not exist",
            parent=get_parent(table, uri)
        )
    page = matches[0]

    if hasattr(page, 'members'):
        subpages = []
        for pointer in matches[0].members:
            table, uid = pointer.split("::")
            subpages += app.db.table(table).search(where("uid") == uid, recurse=False)
        page.members = subpages

    return page


def rendered(page: schema.Record, template: str = "page.html"):
    if not page:
        return Response("Page not found", status=404)
    return render_template(template, page=page, app=app, breadcrumbs=breadcrumbs())


def get_static(path):
    return Response("OK", status=200)


def breadcrumbs():
    """
    Return (uri, name) pairs for the parents leading from the VIEW_URI to the current request.
    """
    if app.config.VIEW_URI != "/":
        root = get_page()
        yield (app.config.VIEW_URI, root.name)
    uri = ""
    for name in relative_uri().split("/"):
        uri = "/".join([uri, name]).lstrip("/")
        yield (uri, name)


@app.web.route("/")
def index():
    return rendered(get_page(create_okay=False))


@app.web.route("/login")
def login():
    app.web.session_interface.regenerate(session)
    g.user = app.db.User.search(where("name") == "admin")[0]
    session['user_id'] = g.user.doc_id
    return redirect(url_for("index"))


@app.web.route("/logout")
def logout():
    if 'user_id' in session:
        del session['user_id']
    del g.user


@app.web.route(f"{app.config.VIEW_URI}/<path:table>/<path:path>", methods=["GET"])
@app.web.route(f"{app.config.VIEW_URI}/<path:path>", methods=["GET"], defaults={'table': 'Page'})
def view(table, path):
    parent = get_parent(table, relative_uri())
    return rendered(get_page(request.path, table=table, create_okay=parent and parent.doc_id is not None))


@app.web.route(f"{app.config.VIEW_URI}/<path:table>/<path:path>", methods=["POST"])
@app.web.route(f"{app.config.VIEW_URI}/<path:path>", methods=["POST"], defaults={'table': 'Page'})
def edit(table, path):
    uri = relative_uri()
    parent = get_parent(table, uri)
    if not parent:
        return Response("You cannot create a page at this location.", status=403)

    # get or create the docoument at this uri
    page = get_page(uri, table=table, create_okay=True)
    save_data = getattr(forms, table)(page, request.form).prepare()

    # editing existing document
    if page.doc_id:
        if page.uid != request.form["uid"]:
            return Response("Invalid UID.", status=403)
        return rendered(app.db.save(save_data))

    # saving a new document
    return rendered(app.add_member(parent, save_data))


@app.web.before_request
def before_request():
    if 'user_id' in session:
        g.user = app.db.User.get(doc_id=session['user_id'])
    elif request.endpoint != 'login':
        return redirect(url_for('login'))


@app.web.after_request
def add_header(r):
    r.headers["Cache-Control"] = "no-cache, no-store, must-revalidate, public, max-age=0"
    r.headers["Pragma"] = "no-cache"
    r.headers["Expires"] = "0"
    return r