/*
Copyright © 2023 AGECEM
*/
package cmd

import (
	"context"
	"crypto/subtle"
	"fmt"
	"log"

	"embed"
	"html/template"
	"io"
	"net/http"
	"sort"

	"github.com/minio/minio-go/v7"
	"github.com/minio/minio-go/v7/pkg/credentials"
	"github.com/spf13/cobra"
	"github.com/spf13/viper"

	"git.agecem.com/agecem/agecem-org/public"
	"github.com/labstack/echo/v4"
	"github.com/labstack/echo/v4/middleware"
)

type Template struct {
	templates *template.Template
}

var embedFS embed.FS

// serverCmd represents the server command
var serverCmd = &cobra.Command{
	Use:   "server",
	Short: "Démarrer le serveur web",
	Run: func(cmd *cobra.Command, args []string) {
		RunServer()
	},
}

func init() {
	rootCmd.AddCommand(serverCmd)
	embedFS = public.GetEmbedFS()

	// server.port    -    --server-port
	serverCmd.Flags().Int("server-port", 8080, "Port to run the webserver on (config: server.port)")
	viper.BindPFlag("server.port", serverCmd.Flags().Lookup("server-port"))

	// server.documents.location    -    --server-documents-location
	serverCmd.Flags().String("server-documents-location", "us-east", "Storage bucket location (config: server.documents.location)")
	viper.BindPFlag("server.documents.location", serverCmd.Flags().Lookup("server-documents-location"))

	// server.documents.endpoint    -    --server-documents-endpoint
	serverCmd.Flags().String("server-documents-endpoint", "minio:9000", "Storage server endpoint (config: server.documents.endpoint)")
	viper.BindPFlag("server.documents.endpoint", serverCmd.Flags().Lookup("server-documents-endpoint"))

	// server.documents.access_key_id    -    --server-documents-access-key-id
	serverCmd.Flags().String("server-documents-access-key-id", "", "Storage server access key id (config: server.documents.access_key_id)")
	viper.BindPFlag("documents.accessKeyID", serverCmd.Flags().Lookup("documents-access-key-id"))

	// server.documents.secret_access_key    -    --server-documents-secret-access-key
	serverCmd.Flags().String("server-documents-secret-access-key", "", "Storage server secret access key (config: server.documents.secret_access_key)")
	viper.BindPFlag("server.documents.secret_access_key", serverCmd.Flags().Lookup("server-documents-secret-access-key"))

	// server.documents.use_ssl    -    --server-documents-use-ssl
	serverCmd.Flags().Bool("server-documents-use-ssl", true, "Storage server SSL status (config: server.documents.use_ssl)")
	viper.BindPFlag("server.documents.use_ssl", serverCmd.Flags().Lookup("server-documents-use-ssl"))

	// server.documents.buckets    -    --server-documents-buckets
	serverCmd.Flags().StringSlice("server-documents-buckets", nil, "Buckets that are allowed to be accessed by the API (config: server.documents.buckets)")
	viper.BindPFlag("server.documents.buckets", serverCmd.Flags().Lookup("server-documents-buckets"))

	// server.api.auth    -    --server-api-auth
	serverCmd.Flags().Bool("server-api-auth", false, "Enable to allow key authentication for /v1 routes (config: server.api.auth)")
	viper.BindPFlag("server.api.auth", serverCmd.Flags().Lookup("server-api-auth"))

	// server.api.key    -    --server-api-key
	serverCmd.Flags().String("server-api-key", "", "Key to use for authenticating to /v1 routes")
	viper.BindPFlag("server.api.key", serverCmd.Flags().Lookup("server-api-key"))
}

func RunServer() {
	e := echo.New()

	t := &Template{
		templates: template.Must(template.ParseFS(embedFS, "html/*.gohtml")),
	}

	e.Renderer = t

	e.Pre(middleware.RemoveTrailingSlash())

	groupV1 := e.Group("/v1")

	groupV1.Use(middleware.AddTrailingSlash())

	if viper.GetBool("server.api.auth") {
		if len(viper.GetString("server.api.key")) < 10 {
			log.Fatal("server.api.auth is enabled, but server.api.key is too small (needs at least 10 characters)")
		}

		groupV1.Use(middleware.KeyAuth(func(key string, c echo.Context) (bool, error) {
			return subtle.ConstantTimeCompare([]byte(key), []byte(viper.GetString("server.api.key"))) == 1, nil
		}))
	}

	// API Routes

	groupV1.GET("", handleV1)

	groupV1.POST("/seed", handleV1Seed)

	groupV1.GET("/bucket", handleV1BucketList)

	groupV1.GET("/bucket/:bucket", handleV1BucketRead)

	// Static Routes

	e.GET("/static/general.css", handleStaticCSSGeneral)

	e.GET("/static/index.css", handleStaticCSSIndex)

	// HTML Routes

	e.GET("/", handleIndex)

	e.GET("/a-propos", handleAPropos)

	e.GET("/actualite", handleActualite)

	e.GET("/actualite/:article", handleActualiteArticle)

	e.GET("/vie-etudiante", handleVieEtudiante)

	e.GET("/vie-etudiante/:organisme", handleVieEtudianteOrganisme)

	e.GET("/documentation", handleDocumentation)

	e.GET("/formulaires", handleFormulaires)

	e.Logger.Fatal(e.Start(
		fmt.Sprintf(":%d", viper.GetInt("server.port"))))
}

func (t *Template) Render(w io.Writer, name string, data interface{}, c echo.Context) error {
	return t.templates.ExecuteTemplate(w, name, data)
}

// API Handlers

// handleV1 affiche les routes accessibles.
// Les routes sont triées selon .Path, pour les rendre plus facilement navigables.
func handleV1(c echo.Context) error {
	routes := c.Echo().Routes()
	sort.Slice(routes, func(i, j int) bool { return routes[i].Path < routes[j].Path })
	return c.JSON(http.StatusOK, routes)
}

// handleV1Seed créé des buckets dans minio selon la liste de buckets dans server.documents.buckets
// Les buckets sont créés avec paramètres par défaut, et sont ensuite visible dans /v1/bucket.
func handleV1Seed(c echo.Context) error {
	documents_buckets := viper.GetStringSlice("server.documents.buckets")
	documents_endpoint := viper.GetString("server.documents.endpoint")
	documents_access_key_id := viper.GetString("server.documents.access_key_id")
	documents_secret_access_key := viper.GetString("server.documents.secret_access_key")
	documents_use_ssl := viper.GetBool("server.documents.use_ssl")

	// Initialize minio client object
	client, err := minio.New(documents_endpoint, &minio.Options{
		Creds:  credentials.NewStaticV4(documents_access_key_id, documents_secret_access_key, ""),
		Secure: documents_use_ssl,
	})
	if err != nil {
		return c.JSON(http.StatusInternalServerError, map[string]string{
			"message": "Error during minio#New",
		})
	}

	var new_buckets []string

	for _, bucket := range documents_buckets {
		exists, err := client.BucketExists(context.Background(), bucket)
		if err != nil {
			return c.JSON(http.StatusInternalServerError, map[string]string{
				"message": "Error during minio#BucketExists",
			})
		}

		if exists {
			continue
		}

		if err = client.MakeBucket(context.Background(), bucket, minio.MakeBucketOptions{}); err != nil {
			return c.JSON(http.StatusInternalServerError, map[string]string{
				"message": "Error during minio#MakeBucket",
			})
		}
		new_buckets = append(new_buckets, bucket)
	}
	var message string
	if len(new_buckets) == 0 {
		message = "All buckets already exist"

	} else {
		message = "Buckets successfully created"
	}

	return c.JSON(http.StatusOK, map[string]interface{}{
		"message": message,
		"buckets": new_buckets,
	})
}

// handleV1BucketList affiche les buckets permis par server.documents.buckets, qui existent.
func handleV1BucketList(c echo.Context) error {
	documents_buckets := viper.GetStringSlice("server.documents.buckets")
	documents_endpoint := viper.GetString("server.documents.endpoint")
	documents_access_key_id := viper.GetString("server.documents.access_key_id")
	documents_secret_access_key := viper.GetString("server.documents.secret_access_key")
	documents_use_ssl := viper.GetBool("server.documents.use_ssl")

	// Initialize minio client object
	client, err := minio.New(documents_endpoint, &minio.Options{
		Creds:  credentials.NewStaticV4(documents_access_key_id, documents_secret_access_key, ""),
		Secure: documents_use_ssl,
	})
	if err != nil {
		return c.JSON(http.StatusInternalServerError, map[string]string{
			"message": "Error during minio#New",
		})
	}

	var buckets []string

	for _, bucket_name := range documents_buckets {
		exists, err := client.BucketExists(context.Background(), bucket_name)
		if err != nil {
			return c.JSON(http.StatusInternalServerError, "Error during minio#BucketExists")
		}

		if exists {
			buckets = append(buckets, bucket_name)
		}
	}

	return c.JSON(http.StatusOK, buckets)
}

func handleV1BucketRead(c echo.Context) error {
	documents_endpoint := viper.GetString("server.documents.endpoint")
	documents_access_key_id := viper.GetString("server.documents.access_key_id")
	documents_secret_access_key := viper.GetString("server.documents.secret_access_key")
	documents_use_ssl := viper.GetBool("server.documents.use_ssl")

	bucket := c.Param("bucket")

	ctx, cancel := context.WithCancel(context.Background())

	defer cancel()

	// Initialize minio client object
	client, err := minio.New(documents_endpoint, &minio.Options{
		Creds:  credentials.NewStaticV4(documents_access_key_id, documents_secret_access_key, ""),
		Secure: documents_use_ssl,
	})
	if err != nil {
		return c.JSON(http.StatusInternalServerError, map[string]string{
			"message": "Error during minio#New",
		})
	}

	exists, err := client.BucketExists(ctx, bucket)
	if err != nil {
		return c.JSON(http.StatusInternalServerError, "Error during minio#BucketExists")
	}

	if !exists {
		return c.JSON(http.StatusNotFound, map[string]string{"message": "Not Found"})
	}

	var keys []string

	objectCh := client.ListObjects(ctx, bucket, minio.ListObjectsOptions{})
	for object := range objectCh {
		if object.Err != nil {
			return c.JSON(http.StatusInternalServerError, map[string]string{
				"message": "Error during minio#ListObjects",
			})
		}

		keys = append(keys, object.Key)
	}

	return c.JSON(http.StatusOK, keys)
}

// HTML Handlers

func handleIndex(c echo.Context) error {
	return c.Render(http.StatusOK, "index-html", nil)
}

func handleAPropos(c echo.Context) error {
	return c.Render(http.StatusOK, "a-propos-html", nil)
}

func handleActualite(c echo.Context) error {
	return c.Render(http.StatusOK, "actualite-html", nil)
}

func handleActualiteArticle(c echo.Context) error {
	article := c.Param("article")
	return c.String(http.StatusOK, fmt.Sprintf("Article: %s", article))
}
func handleVieEtudiante(c echo.Context) error {
	return c.Render(http.StatusOK, "vie-etudiante-html", nil)
}
func handleVieEtudianteOrganisme(c echo.Context) error {
	organisme := c.Param("organisme")
	return c.String(http.StatusOK, fmt.Sprintf("Organisme: %s", organisme))
}
func handleDocumentation(c echo.Context) error {
	return c.Render(http.StatusOK, "documentation-html", nil)
}
func handleFormulaires(c echo.Context) error {
	return c.Render(http.StatusOK, "formulaires-html", nil)
}

// CSS Handlers

func handleStaticCSSIndex(c echo.Context) error {
	// TODO Ajouter gestion d'erreurs
	data, _ := embedFS.ReadFile("css/index.css")
	return c.Blob(http.StatusOK, "text/css", data)
}

func handleStaticCSSGeneral(c echo.Context) error {
	// TODO Ajouter gestion d'erreurs
	data, _ := embedFS.ReadFile("css/general.css")
	return c.Blob(http.StatusOK, "text/css", data)
}