package api

import (
	"encoding/json"
	"fmt"
	"net/http"
	"net/url"

	"github.com/go-chi/chi"
	"github.com/gorilla/schema"
	"github.com/gorilla/websocket"
	"github.com/porter-dev/porter/internal/forms"
	"github.com/porter-dev/porter/internal/kubernetes"
	"github.com/porter-dev/porter/internal/kubernetes/prometheus"
	v1 "k8s.io/api/core/v1"
)

// Enumeration of k8s API error codes, represented as int64
const (
	ErrK8sDecode ErrorCode = iota + 600
	ErrK8sValidate
)

var upgrader = websocket.Upgrader{
	ReadBufferSize:  1024,
	WriteBufferSize: 1024,
}

// HandleListNamespaces retrieves a list of namespaces
func (app *App) HandleListNamespaces(w http.ResponseWriter, r *http.Request) {
	vals, err := url.ParseQuery(r.URL.RawQuery)

	if err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}

	// get the filter options
	form := &forms.K8sForm{
		OutOfClusterConfig: &kubernetes.OutOfClusterConfig{
			Repo:              app.Repo,
			DigitalOceanOAuth: app.DOConf,
		},
	}

	form.PopulateK8sOptionsFromQueryParams(vals, app.Repo.Cluster)

	// validate the form
	if err := app.validator.Struct(form); err != nil {
		app.handleErrorFormValidation(err, ErrK8sValidate, w)
		return
	}

	// create a new agent
	var agent *kubernetes.Agent

	if app.ServerConf.IsTesting {
		agent = app.TestAgents.K8sAgent
	} else {
		agent, err = kubernetes.GetAgentOutOfClusterConfig(form.OutOfClusterConfig)
	}

	namespaces, err := agent.ListNamespaces()

	if err != nil {
		app.handleErrorDataRead(err, w)
		return
	}

	if err := json.NewEncoder(w).Encode(namespaces); err != nil {
		app.handleErrorFormDecoding(err, ErrK8sDecode, w)
		return
	}
}

// HandleGetPodLogs returns real-time logs of the pod via websockets
// TODO: Refactor repeated calls.
func (app *App) HandleGetPodLogs(w http.ResponseWriter, r *http.Request) {

	// get session to retrieve correct kubeconfig
	_, err := app.Store.Get(r, app.ServerConf.CookieName)

	// get path parameters
	namespace := chi.URLParam(r, "namespace")
	podName := chi.URLParam(r, "name")

	if err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}

	vals, err := url.ParseQuery(r.URL.RawQuery)

	if err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}

	// get the filter options
	form := &forms.K8sForm{
		OutOfClusterConfig: &kubernetes.OutOfClusterConfig{
			Repo:              app.Repo,
			DigitalOceanOAuth: app.DOConf,
		},
	}

	form.PopulateK8sOptionsFromQueryParams(vals, app.Repo.Cluster)

	// validate the form
	if err := app.validator.Struct(form); err != nil {
		app.handleErrorFormValidation(err, ErrK8sValidate, w)
		return
	}

	// create a new agent
	var agent *kubernetes.Agent

	if app.ServerConf.IsTesting {
		agent = app.TestAgents.K8sAgent
	} else {
		agent, err = kubernetes.GetAgentOutOfClusterConfig(form.OutOfClusterConfig)
	}

	upgrader.CheckOrigin = func(r *http.Request) bool { return true }

	// upgrade to websocket.
	conn, err := upgrader.Upgrade(w, r, nil)

	if err != nil {
		app.handleErrorUpgradeWebsocket(err, w)
	}

	err = agent.GetPodLogs(namespace, podName, conn)

	if err != nil {
		app.handleErrorWebsocketWrite(err, w)
		return
	}
}

// HandleGetIngress returns the ingress object given the name and namespace.
func (app *App) HandleGetIngress(w http.ResponseWriter, r *http.Request) {

	// get session to retrieve correct kubeconfig
	_, err := app.Store.Get(r, app.ServerConf.CookieName)

	// get path parameters
	namespace := chi.URLParam(r, "namespace")
	name := chi.URLParam(r, "name")

	if err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}

	vals, err := url.ParseQuery(r.URL.RawQuery)

	if err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}

	// get the filter options
	form := &forms.K8sForm{
		OutOfClusterConfig: &kubernetes.OutOfClusterConfig{
			Repo:              app.Repo,
			DigitalOceanOAuth: app.DOConf,
		},
	}

	form.PopulateK8sOptionsFromQueryParams(vals, app.Repo.Cluster)

	// validate the form
	if err := app.validator.Struct(form); err != nil {
		app.handleErrorFormValidation(err, ErrK8sValidate, w)
		return
	}

	// create a new agent
	var agent *kubernetes.Agent

	if app.ServerConf.IsTesting {
		agent = app.TestAgents.K8sAgent
	} else {
		agent, err = kubernetes.GetAgentOutOfClusterConfig(form.OutOfClusterConfig)
	}

	ingress, err := agent.GetIngress(namespace, name)

	if err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}

	if err := json.NewEncoder(w).Encode(ingress); err != nil {
		app.handleErrorFormDecoding(err, ErrK8sDecode, w)
		return
	}
}

// HandleListPods returns all pods that match the given selectors
// TODO: Refactor repeated calls.
func (app *App) HandleListPods(w http.ResponseWriter, r *http.Request) {

	// get session to retrieve correct kubeconfig
	_, err := app.Store.Get(r, app.ServerConf.CookieName)

	if err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}

	vals, err := url.ParseQuery(r.URL.RawQuery)

	if err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}

	// get the filter options
	form := &forms.K8sForm{
		OutOfClusterConfig: &kubernetes.OutOfClusterConfig{
			Repo:              app.Repo,
			DigitalOceanOAuth: app.DOConf,
		},
	}

	form.PopulateK8sOptionsFromQueryParams(vals, app.Repo.Cluster)

	// validate the form
	if err := app.validator.Struct(form); err != nil {
		app.handleErrorFormValidation(err, ErrK8sValidate, w)
		return
	}

	// create a new agent
	var agent *kubernetes.Agent

	if app.ServerConf.IsTesting {
		agent = app.TestAgents.K8sAgent
	} else {
		agent, err = kubernetes.GetAgentOutOfClusterConfig(form.OutOfClusterConfig)
	}

	pods := []v1.Pod{}
	for _, selector := range vals["selectors"] {
		podsList, err := agent.GetPodsByLabel(selector)

		if err != nil {
			app.handleErrorFormValidation(err, ErrK8sValidate, w)
			return
		}

		for _, pod := range podsList.Items {
			pods = append(pods, pod)
		}
	}

	if err := json.NewEncoder(w).Encode(pods); err != nil {
		app.handleErrorFormDecoding(err, ErrK8sDecode, w)
		return
	}
}

// HandleStreamControllerStatus test calls
// TODO: Refactor repeated calls.
func (app *App) HandleStreamControllerStatus(w http.ResponseWriter, r *http.Request) {

	// get session to retrieve correct kubeconfig
	_, err := app.Store.Get(r, app.ServerConf.CookieName)

	if err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}

	vals, err := url.ParseQuery(r.URL.RawQuery)

	if err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}

	// get the filter options
	form := &forms.K8sForm{
		OutOfClusterConfig: &kubernetes.OutOfClusterConfig{
			Repo:              app.Repo,
			DigitalOceanOAuth: app.DOConf,
		},
	}

	form.PopulateK8sOptionsFromQueryParams(vals, app.Repo.Cluster)

	// validate the form
	if err := app.validator.Struct(form); err != nil {
		app.handleErrorFormValidation(err, ErrK8sValidate, w)
		return
	}

	// create a new agent
	var agent *kubernetes.Agent

	if app.ServerConf.IsTesting {
		agent = app.TestAgents.K8sAgent
	} else {
		agent, err = kubernetes.GetAgentOutOfClusterConfig(form.OutOfClusterConfig)
	}

	upgrader.CheckOrigin = func(r *http.Request) bool { return true }

	// upgrade to websocket.
	conn, err := upgrader.Upgrade(w, r, nil)

	if err != nil {
		app.handleErrorUpgradeWebsocket(err, w)
	}

	// get path parameters
	kind := chi.URLParam(r, "kind")
	err = agent.StreamControllerStatus(conn, kind)

	if err != nil {
		app.handleErrorWebsocketWrite(err, w)
		return
	}
}

// HandleDetectPrometheusInstalled detects a prometheus installation in the target cluster
func (app *App) HandleDetectPrometheusInstalled(w http.ResponseWriter, r *http.Request) {
	vals, err := url.ParseQuery(r.URL.RawQuery)

	if err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}

	// get the filter options
	form := &forms.K8sForm{
		OutOfClusterConfig: &kubernetes.OutOfClusterConfig{
			Repo:              app.Repo,
			DigitalOceanOAuth: app.DOConf,
		},
	}

	form.PopulateK8sOptionsFromQueryParams(vals, app.Repo.Cluster)

	// validate the form
	if err := app.validator.Struct(form); err != nil {
		app.handleErrorFormValidation(err, ErrK8sValidate, w)
		return
	}

	// create a new agent
	var agent *kubernetes.Agent

	if app.ServerConf.IsTesting {
		agent = app.TestAgents.K8sAgent
	} else {
		agent, err = kubernetes.GetAgentOutOfClusterConfig(form.OutOfClusterConfig)
	}

	// detect prometheus service
	_, found, err := prometheus.GetPrometheusService(agent.Clientset)

	if !found {
		http.NotFound(w, r)
		return
	}

	w.WriteHeader(http.StatusOK)
	return
}

func (app *App) HandleGetPodMetrics(w http.ResponseWriter, r *http.Request) {
	vals, err := url.ParseQuery(r.URL.RawQuery)

	if err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}

	// get the filter options
	form := &forms.MetricsQueryForm{
		K8sForm: &forms.K8sForm{
			OutOfClusterConfig: &kubernetes.OutOfClusterConfig{
				Repo:              app.Repo,
				DigitalOceanOAuth: app.DOConf,
			},
		},
		QueryOpts: &prometheus.QueryOpts{},
	}

	form.K8sForm.PopulateK8sOptionsFromQueryParams(vals, app.Repo.Cluster)

	// decode from JSON to form value
	decoder := schema.NewDecoder()
	decoder.IgnoreUnknownKeys(true)

	if err := decoder.Decode(form.QueryOpts, vals); err != nil {
		app.handleErrorFormDecoding(err, ErrProjectDecode, w)
		return
	}

	// validate the form
	if err := app.validator.Struct(form); err != nil {
		app.handleErrorFormValidation(err, ErrK8sValidate, w)
		return
	}

	// create a new agent
	var agent *kubernetes.Agent

	if app.ServerConf.IsTesting {
		agent = app.TestAgents.K8sAgent
	} else {
		agent, err = kubernetes.GetAgentOutOfClusterConfig(form.OutOfClusterConfig)
	}

	// get prometheus service
	promSvc, found, err := prometheus.GetPrometheusService(agent.Clientset)

	if err != nil {
		app.handleErrorInternal(err, w)
		return
	}

	if !found {
		app.handleErrorInternal(err, w)
		return
	}

	rawQuery, err := prometheus.QueryPrometheus(agent.Clientset, promSvc, form.QueryOpts)

	if err != nil {
		app.handleErrorInternal(err, w)
		return
	}

	fmt.Fprint(w, string(rawQuery))
}