from flask import Response, render_template, request
from tinydb import where

from ttfrog import app, schema
from ttfrog.forms import PageForm

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(uri: str):
    try:
        parent_uri = uri.strip("/").split("/", -1)[0]
    except IndexError:
        return None
    app.web.logger.debug(f"Looking for parent with {parent_uri = }")
    return get_page(parent_uri or "/", create_okay=False)


def get_page(path: str = "", create_okay: bool = False):
    """
    Get one page, including its subpages, but not recursively.
    """
    uri = path or relative_uri(request.path)
    matches = app.db.Page.search(where("uri") == uri, recurse=False)
    app.web.logger.debug(f"Found {len(matches)} pages where {uri = }")
    if not matches:
        if not create_okay:
            return None
        return schema.Page(stub=uri.split("/")[-1], body="This page does not exist", parent=get_parent(uri))
    uids = [pointer.split("::")[-1] for pointer in matches[0].pages]
    subpages = app.db.Page.search(where("uid").one_of(uids), recurse=False)
    matches[0].pages = subpages
    return matches[0]


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, stub) 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.stub)
    uri = ""
    for stub in relative_uri().split("/"):
        uri = "/".join([uri, stub]).lstrip("/")
        yield (uri, stub)


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


@app.web.route(f"{app.config.VIEW_URI}/<path:path>", methods=["GET"])
def view(path):
    return rendered(get_page(request.path, create_okay=True))


@app.web.route(f"{app.config.VIEW_URI}/<path:path>", methods=["POST"])
def edit(path):
    uri = relative_uri()
    parent = get_parent(uri)
    app.web.logger.debug(f"Handling form submission: {uri = }, {parent = }, {request.form = }")
    if not parent:
        return Response(f"Parent for {uri} does not exist.", status=403)

    page = get_page(uri, create_okay=True)
    app.web.logger.debug(f"Editing {page.doc_id} for {uri = }")
    if page.doc_id:
        if page.uid != request.form["uid"]:
            return Response("Invalid UID.", status=403)

    form = PageForm(page, request.form)
    page = app.db.save(form.prepare())
    app.web.logger.debug(f"Saved {page.doc_id}; now updating parent {parent.doc_id}")
    parent.pages.append(page)
    app.db.save(parent)
    return get_page(stub)


@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