use actix_web::{web, HttpRequest, Responder, HttpResponse};
use crate::TERA;
use crate::tera_ext::TeraExt;
use yopa::{Storage, StorageError, ID};
use serde::{Deserialize, Serialize};
use yopa::model::{PropertyModel, RelationModel, ObjectModel};
use std::ops::DerefMut;
use actix_session::Session;
use crate::session_ext::SessionExt;
use std::str::FromStr;
use std::fmt::{Debug, Display};
use actix_web::http::header::IntoHeaderValue;

#[derive(Serialize, Debug)]
struct ObjectModelDisplay<'a> {
    id : yopa::ID,
    name : &'a str,
    properties: Vec<&'a PropertyModel>,
    relations: Vec<RelationModelDisplay<'a>>,
}

#[derive(Serialize, Debug)]
struct RelationModelDisplay<'a> {
    model : &'a RelationModel,
    related_name : &'a str,
    properties: Vec<&'a PropertyModel>,
}

fn redirect(path : impl IntoHeaderValue) -> actix_web::Result<HttpResponse> {
    Ok(HttpResponse::SeeOther()
        .header("location", path) // back - to where?
        .finish())
}

trait ParseOrBadReq {
    fn parse_or_bad_request<T, E>(&self) -> actix_web::Result<T>
    where T: FromStr<Err=E>,
          E: Display + Debug + 'static;
}

impl ParseOrBadReq for &str {
    fn parse_or_bad_request<T, E>(&self) -> actix_web::Result<T>
        where T: FromStr<Err=E>,
              E: Display + Debug + 'static
    {
        self.parse::<T>()
            .map_err(|e| actix_web::error::ErrorBadRequest(e))
    }
}

impl ParseOrBadReq for String {
    fn parse_or_bad_request<T, E>(&self) -> actix_web::Result<T>
        where T: FromStr<Err=E>,
              E: Display + Debug + 'static
    {
        self.as_str()
            .parse_or_bad_request()
    }
}


#[get("/")]
pub(crate) async fn index(session : Session, store : crate::YopaStoreWrapper) -> actix_web::Result<impl Responder> {

    let rg = store.read().await;

    let models_iter = rg.get_object_models();

    // object and relation props
    let mut model_props = rg.get_grouped_prop_models();

    let mut model_relations = rg.get_grouped_relation_models();

    let mut models = vec![];
    for om in models_iter {
        let mut oprops = model_props.remove(&om.id).unwrap_or_default();
        let mut relations = model_relations.remove(&om.id).unwrap_or_default();

        let rel_displays = relations.into_iter().map(|rm| {
            let mut rprops = model_props.remove(&rm.id).unwrap_or_default();
            rprops.sort_by_key(|m| &m.name);

            RelationModelDisplay {
                model: rm,
                related_name: rg.get_model_name(rm.related),
                properties: rprops
            }

        }).collect::<Vec<_>>();

        oprops.sort_by_key(|m| &m.name);

        models.push(ObjectModelDisplay {
            id: om.id,
            name: &om.name,
            properties: oprops,
            relations: rel_displays,
        })
    }

    models.sort_by_key(|m| m.name);

    let mut ctx = tera::Context::new();
    ctx.insert("models", &models);
    session.render_flash(&mut ctx);

    TERA.build_response("index", &ctx)
}

#[get("/model/object/create")]
pub(crate) async fn object_model_create_form(session : Session) -> actix_web::Result<impl Responder> {
    let mut context = tera::Context::new();
    session.render_flash(&mut context);

    TERA.build_response("model_create", &context)
}

#[derive(Deserialize)]
pub(crate) struct ObjectModelCreate {
    pub name : String,
}

#[post("/model/object/create")]
pub(crate) async fn object_model_create(
    form : web::Form<ObjectModelCreate>,
    store : crate::YopaStoreWrapper,
    session : Session
) -> actix_web::Result<impl Responder> {
    let mut wg = store.write().await;
    let form = form.into_inner();
    match wg.define_object(ObjectModel {
        id: Default::default(),
        name: form.name.clone()
    }) {
        Ok(_id) => {
            debug!("Object created, redirecting to root");
            session.flash_success(format!("Object model \"{}\" created.", form.name));
            redirect("/")
        }
        Err(e) => {
            warn!("Error creating model: {:?}", e);
            session.flash_error(e.to_string());
            redirect("/model/object/create")
        }
    }
}

#[get("/model/relation/create/{object_id}")]
pub(crate) async fn relation_model_create_form(
    object_id : web::Path<String>,
    store : crate::YopaStoreWrapper,
    session : Session
) -> actix_web::Result<impl Responder> {
    let mut context = tera::Context::new();
    session.render_flash(&mut context);

    let rg = store.read().await;

    debug!("ID = {}", object_id);

    let object = rg.get_object_model(object_id.parse_or_bad_request()?)
        .ok_or_else(|| actix_web::error::ErrorNotFound("No such source object"))?;

    let mut models: Vec<_> = rg.get_object_models().collect();

    models.sort_by_key(|m| &m.name);

    context.insert("models", &models);
    context.insert("object", &object);

    TERA.build_response("relation_create", &context)
}

#[derive(Deserialize)]
pub(crate) struct RelationModelCreate {
    pub object : ID,
    pub name : String,
    pub optional : Option<i32>,
    pub multiple : Option<i32>,
    pub related : ID,
}

#[post("/model/relation/create")]
pub(crate) async fn relation_model_create(
    form : web::Form<RelationModelCreate>,
    store : crate::YopaStoreWrapper,
    session : Session
) -> actix_web::Result<impl Responder> {
    let mut wg = store.write().await;
    let form = form.into_inner();
    match wg.define_relation(RelationModel {
        id: Default::default(),
        object: form.object,
        name: form.name.clone(),
        optional: form.optional.unwrap_or_default() != 0,
        multiple: form.multiple.unwrap_or_default() != 0,
        related: form.related
    }) {
        Ok(_id) => {
            debug!("Relation created, redirecting to root");
            session.flash_success(format!("Relation model \"{}\" created.", form.name));
            redirect("/")
        }
        Err(e) => {
            warn!("Error creating relation model: {:?}", e);
            session.flash_error(e.to_string());
            redirect(format!("/model/relation/create/{}", form.object))
        }
    }
}

#[get("/model/object/delete/{id}")]
pub(crate) async fn object_model_delete(
    id : web::Path<String>,
    store : crate::YopaStoreWrapper,
    session : Session
) -> actix_web::Result<impl Responder> {
    let mut wg = store.write().await;
    match wg.undefine_object(id.parse().map_err(|e| actix_web::error::ErrorBadRequest(e))?) {
        Ok(om) => {
            debug!("Object model deleted, redirecting to root");
            session.flash_success(format!("Object model \"{}\" deleted.", om.name));
            redirect("/")
        }
        Err(e) => {
            warn!("Error deleting object model: {:?}", e);
            session.flash_error(e.to_string());
            redirect("/") // back?
        }
    }
}

#[get("/model/relation/delete/{id}")]
pub(crate) async fn relation_model_delete(
    id : web::Path<String>,
    store : crate::YopaStoreWrapper,
    session : Session
) -> actix_web::Result<impl Responder> {
    let mut wg = store.write().await;
    match wg.undefine_relation(id.parse_or_bad_request()?) {
        Ok(rm) => {
            debug!("Relation deleted, redirecting to root");
            session.flash_success(format!("Relation model \"{}\" deleted.", rm.name));
            redirect("/")
        }
        Err(e) => {
            warn!("Error deleting relation model: {:?}", e);
            session.flash_error(e.to_string());
            redirect("/") // back?
        }
    }
}

#[get("/model/property/delete/{id}")]
pub(crate) async fn property_model_delete(
    id : web::Path<String>,
    store : crate::YopaStoreWrapper,
    session : Session
) -> actix_web::Result<impl Responder> {
    let mut wg = store.write().await;
    match wg.undefine_property(id.parse_or_bad_request()?) {
        Ok(rm) => {
            debug!("Property deleted, redirecting to root");
            session.flash_success(format!("Property \"{}\" deleted.", rm.name));
            redirect("/")
        }
        Err(e) => {
            warn!("Error deleting property: {:?}", e);
            session.flash_error(e.to_string());
            redirect("/") // back?
        }
    }
}