use actix_session::Session;
use actix_web::{Responder, web, HttpResponse};
use crate::session_ext::SessionExt;
use crate::routes::models::object::ObjectModelForm;
use crate::TERA;
use crate::tera_ext::TeraExt;
use yopa::{ID, model};
use yopa::data::Object;
use serde::{Serialize,Deserialize};
use yopa::insert::InsertObj;
use crate::utils::redirect;
use actix_web::web::Json;
use serde_json::Value;
use itertools::Itertools;
use yopa::model::{ObjectModel, PropertyModel, RelationModel};
use heck::TitleCase;

// we only need references here, Context serializes everything to Value.
// cloning would be a waste of cycles

#[derive(Debug, Default, Serialize, Clone)]
pub struct Schema<'a> {
    pub obj_models: Vec<&'a model::ObjectModel>,
    pub rel_models: Vec<&'a model::RelationModel>,
    pub prop_models: Vec<&'a model::PropertyModel>,
}

#[derive(Serialize,Debug,Clone)]
pub struct ObjectCreateData<'a> {
    pub model_id: ID,
    pub schema: Schema<'a>,
    pub objects: Vec<&'a Object>,
}

#[get("/object/create/{model_id}")]
pub(crate) async fn create_form(
    model_id: web::Path<ID>,
    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;

    let model = rg.get_object_model(*model_id)
        .ok_or_else(|| actix_web::error::ErrorNotFound("No such model"))?;

    context.insert("model", model);

    let relations : Vec<_> = rg.get_relation_models_for_object_model(model.id).collect();

    let mut prop_object_ids : Vec<ID> = relations.iter().map(|r| r.id).collect();
    prop_object_ids.push(model.id);

    prop_object_ids.sort();
    prop_object_ids.dedup();

    let mut related_ids : Vec<_> = relations.iter().map(|r| r.related).collect();

    related_ids.sort();
    related_ids.dedup();

    let form_data = ObjectCreateData {
        model_id: model.id,
        schema: Schema {
            obj_models: rg.get_object_models().collect(), // TODO get only the ones that matter here
            rel_models: relations,
            prop_models: rg.get_property_models_for_parents(&prop_object_ids).collect()
        },
        objects: rg.get_objects_of_type(&related_ids).collect()
    };

    context.insert("form_data", &form_data);

    TERA.build_response("objects/object_create", &context)
}

#[post("/object/create")]
pub(crate) async fn create(
    form: web::Json<InsertObj>,
    store: crate::YopaStoreWrapper,
    session: Session,
) -> actix_web::Result<impl Responder> {
    warn!("{:?}", form);

    // let des : InsertObj = serde_json::from_value(form.into_inner()).unwrap();
    //
    // Ok(HttpResponse::Ok().finish())
    //

    let mut wg = store.write().await;
    let form = form.into_inner();
    let name = form.name.clone();

    let model_name = wg.get_model_name(form.model_id).to_owned().to_title_case();

    match wg.insert_object(form) {
        Ok(_id) => {
            debug!("Object created, redirecting to root");
            session.flash_success(format!("{} \"{}\" created.", model_name, name));
            Ok(HttpResponse::Ok().finish())
        }
        Err(e) => {
            warn!("Error creating model: {}", e);
            Ok(HttpResponse::BadRequest().body(e.to_string()))
        }
    }
}

#[derive(Debug, Serialize, Clone)]
struct ModelWithObjects<'a> {
    model : &'a ObjectModel,
    objects: Vec<&'a Object>
}

#[get("/objects")]
pub(crate) async fn list(session: Session, store: crate::YopaStoreWrapper) -> actix_web::Result<impl Responder> {
    list_inner(session, store).await
}

pub(crate) async fn list_inner(session: Session, store: crate::YopaStoreWrapper) -> actix_web::Result<HttpResponse> {
    let rg = store.read().await;

    let mut objects_by_model = rg.get_grouped_objects();

    let mut models : Vec<_> = rg.get_object_models()
        .sorted_by_key(|m| &m.name)
        .map(|model| {
            let mut objects = objects_by_model.remove(&model.id).unwrap_or_default();
            objects.sort_by_key(|o| &o.name);
            ModelWithObjects {
                model,
                objects
            }
        }).collect();

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

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

#[derive(Debug,Serialize)]
struct PropertyView<'a> {
    model : &'a PropertyModel,
    values: Vec<&'a yopa::data::Value>
}

#[derive(Debug,Serialize)]
struct RelationView<'a> {
    model : &'a RelationModel,
    related_name: &'a str,
    instances: Vec<RelationInstanceView<'a>>
}

#[derive(Debug,Serialize)]
struct RelationInstanceView<'a> {
    related: &'a Object,
    properties: Vec<PropertyView<'a>>
}


#[get("/object/detail/{id}")]
pub(crate) async fn detail(
    id: web::Path<ID>,
    store: crate::YopaStoreWrapper
) -> actix_web::Result<impl Responder> {
    let object_id = *id;

    let mut context = tera::Context::new();

    let rg = store.read().await;

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

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

    context.insert("object", object);
    context.insert("model", model);
    context.insert("kind", &rg.get_model_name(object.model));

    let relations = rg.get_relations_for_object(object_id).collect_vec();

    // values by parent ID
    let mut ids_to_get_values_for = relations.iter().map(|r| r.id).collect_vec();
    ids_to_get_values_for.push(object_id);
    let mut grouped_values = {
        rg.get_grouped_values_for_objects(&ids_to_get_values_for)
    };

    // object's own properties
    {
        let mut object_values_by_model = grouped_values
            .remove(&object_id).unwrap_or_default().into_iter()
            .into_group_map_by(|value| value.model);

        let mut view_object_properties = vec![];
        for (prop_model_id, values) in object_values_by_model {
            view_object_properties.push(PropertyView {
                model: rg.get_property_model(prop_model_id).unwrap(),
                values
            })
        }
        context.insert("properties", &view_object_properties);
    }

    // go through relations
    {
        let grouped_relations = relations.iter()
            .into_group_map_by(|relation| relation.model);

        let mut relation_views = vec![];
        for (model_id, relations) in grouped_relations {
            let mut instances = vec![];

            for rel in relations {
                let related_obj = match rg.get_object(rel.related) {
                    None => continue,
                    Some(obj) => obj
                };

                let mut rel_values_by_model = grouped_values
                    .remove(&rel.id).unwrap_or_default().into_iter()
                    .into_group_map_by(|value| value.model);

                let mut view_rel_properties = vec![];
                for (prop_model_id, values) in rel_values_by_model {
                    view_rel_properties.push(PropertyView {
                        model: rg.get_property_model(prop_model_id).unwrap(),
                        values
                    })
                }

                instances.push(RelationInstanceView {
                    related: related_obj,
                    properties: view_rel_properties
                })
            }

            relation_views.push(RelationView {
                model: rg.get_relation_model(model_id).unwrap(),
                related_name: rg.get_model_name(model_id),
                instances
            })
        }
        context.insert("relations", &relation_views);
    }

    TERA.build_response("objects/object_detail", &context)
}