/*
 * Copyright 2020 Intel Corporation, Inc
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package api

import (
	"encoding/json"
	"io"
	"net/http"

	"github.com/gorilla/mux"
	"github.com/onap/multicloud-k8s/src/orchestrator/pkg/infra/validation"
	moduleLib "github.com/onap/multicloud-k8s/src/orchestrator/pkg/module"
)

/* Used to store backend implementation objects
Also simplifies mocking for unit testing purposes
*/
type appIntentHandler struct {
	client moduleLib.AppIntentManager
}

// createAppIntentHandler handles the create operation of intent
func (h appIntentHandler) createAppIntentHandler(w http.ResponseWriter, r *http.Request) {

	var a moduleLib.AppIntent

	err := json.NewDecoder(r.Body).Decode(&a)
	switch {
	case err == io.EOF:
		http.Error(w, "Empty body", http.StatusBadRequest)
		return
	case err != nil:
		http.Error(w, err.Error(), http.StatusUnprocessableEntity)
		return
	}

	if a.MetaData.Name == "" {
		http.Error(w, "Missing AppIntentName in POST request", http.StatusBadRequest)
		return
	}

	vars := mux.Vars(r)
	projectName := vars["project-name"]
	compositeAppName := vars["composite-app-name"]
	version := vars["composite-app-version"]
	intent := vars["intent-name"]

	appIntent, createErr := h.client.CreateAppIntent(a, projectName, compositeAppName, version, intent)
	if createErr != nil {
		http.Error(w, createErr.Error(), http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusCreated)
	err = json.NewEncoder(w).Encode(appIntent)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
}

func (h appIntentHandler) getAppIntentHandler(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)

	p := vars["project-name"]
	if p == "" {
		http.Error(w, "Missing projectName in GET request", http.StatusBadRequest)
		return
	}
	ca := vars["composite-app-name"]
	if ca == "" {
		http.Error(w, "Missing compositeAppName in GET request", http.StatusBadRequest)
		return
	}

	v := vars["composite-app-version"]
	if v == "" {
		http.Error(w, "Missing version of compositeApp in GET request", http.StatusBadRequest)
		return
	}

	i := vars["intent-name"]
	if i == "" {
		http.Error(w, "Missing genericPlacementIntentName in GET request", http.StatusBadRequest)
		return
	}

	ai := vars["app-intent-name"]
	if ai == "" {
		http.Error(w, "Missing appIntentName in GET request", http.StatusBadRequest)
		return
	}

	appIntent, err := h.client.GetAppIntent(ai, p, ca, v, i)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusOK)
	err = json.NewEncoder(w).Encode(appIntent)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

}

/*
getAllIntentsByAppHandler handles the URL:
/v2/project/{project-name}/composite-apps/{composite-app-name}/{version}/generic-placement-intent/{intent-name}/app-intents?app-name=<app-name>
*/
func (h appIntentHandler) getAllIntentsByAppHandler(w http.ResponseWriter, r *http.Request) {

	vars := mux.Vars(r)
	pList := []string{"project-name", "composite-app-name", "composite-app-version", "intent-name"}
	err := validation.IsValidParameterPresent(vars, pList)
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
	}
	p := vars["project-name"]
	ca := vars["composite-app-name"]
	v := vars["composite-app-version"]
	i := vars["intent-name"]
	aN := r.URL.Query().Get("app-name")
	if aN == "" {
		http.Error(w, "Missing appName in GET request", http.StatusBadRequest)
		return
	}

	specData, err := h.client.GetAllIntentsByApp(aN, p, ca, v, i)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusOK)
	err = json.NewEncoder(w).Encode(specData)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	return

}

/*
getAllAppIntentsHandler handles the URL:
/v2/project/{project-name}/composite-apps/{composite-app-name}/{version}/generic-placement-intent/{intent-name}/app-intents
*/
func (h appIntentHandler) getAllAppIntentsHandler(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	pList := []string{"project-name", "composite-app-name", "composite-app-version", "intent-name"}
	err := validation.IsValidParameterPresent(vars, pList)
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
	}
	p := vars["project-name"]
	ca := vars["composite-app-name"]
	v := vars["composite-app-version"]
	i := vars["intent-name"]

	applicationsAndClusterInfo, err := h.client.GetAllAppIntents(p, ca, v, i)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusOK)
	err = json.NewEncoder(w).Encode(applicationsAndClusterInfo)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	return

}

func (h appIntentHandler) deleteAppIntentHandler(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)

	p := vars["project-name"]
	ca := vars["composite-app-name"]
	v := vars["composite-app-version"]
	i := vars["intent-name"]
	ai := vars["app-intent-name"]

	err := h.client.DeleteAppIntent(ai, p, ca, v, i)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	w.WriteHeader(http.StatusNoContent)
}