//go:generate npm --prefix frontend run build
package main

import (
    "embed"
    "github.com/chi-middleware/logrus-logger"
    "github.com/go-chi/chi/v5"
    "github.com/go-chi/cors"
    "github.com/go-chi/httprate"
    log "github.com/sirupsen/logrus"
    httpSwagger "github.com/swaggo/http-swagger"
    "github.com/tdewolff/minify/v2"
    "github.com/tdewolff/minify/v2/css"
    "github.com/tdewolff/minify/v2/html"
    "github.com/tdewolff/minify/v2/js"
    "github.com/tdewolff/minify/v2/json"
    "github.com/tdewolff/minify/v2/svg"
    "github.com/tdewolff/minify/v2/xml"
    "io"
    "io/fs"
    _ "minify.ccatss.dev/docs"
    "net/http"
    "regexp"
    "strings"
    "time"
)

var (
    //go:embed frontend/dist
    frontendFs embed.FS

    //go:embed LICENSE.txt
    licenseBytes []byte
)

// @title Minifier API
// @version 1.0
// @description An API Implementation of tdewolfe's minify package
// @termsOfService http://swagger.io/terms/

// @contact.name ccatss
// @contact.url https://ccatss.dev
// @contact.email admin@meow.tf

// @license.name ISC License
// @license.url /LICENSE.txt

// @host minify.ccatss.dev
// @BasePath /api
func main() {
    r := chi.NewRouter()

    r.Use(logger.Logger("router", log.StandardLogger()))

    m := minify.New()
    m.AddFunc("text/css", css.Minify)
    m.AddFunc("text/html", html.Minify)
    m.AddFunc("image/svg+xml", svg.Minify)
    m.AddFuncRegexp(regexp.MustCompile("^(application|text)/(x-)?(java|ecma)script$"), js.Minify)
    m.AddFuncRegexp(regexp.MustCompile("[/+]json$"), json.Minify)
    m.AddFuncRegexp(regexp.MustCompile("[/+]xml$"), xml.Minify)

    subFs, err := fs.Sub(frontendFs, "frontend/dist")

    if err != nil {
        log.WithError(err).Fatalln("Unable to load frontend")
    }

    httpFs := http.FileServer(http.FS(subFs))

    r.Handle("/", httpFs)
    r.Handle("/js/*", httpFs)
    r.Handle("/css/*", httpFs)

    r.Get("/LICENSE.txt", func(w http.ResponseWriter, r *http.Request) {
        w.Write(licenseBytes)
    })

    r.Get("/swagger/*", httpSwagger.Handler(
        httpSwagger.URL("/swagger/doc.json"), //The url pointing to API definition
    ))

    r.Route("/api", func(r chi.Router) {
        r.Use(httprate.LimitByIP(100, 1*time.Minute))

        r.Use(cors.Handler(cors.Options{
            AllowedOrigins:   []string{"https://*", "http://*"},
            AllowedMethods:   []string{"GET", "POST", "OPTIONS"},
            AllowedHeaders:   []string{"Accept", "Content-Type"},
            ExposedHeaders:   []string{"Link"},
            AllowCredentials: false,
            MaxAge:           300, // Maximum value not ignored by any of major browsers
        }))

        r.Post("/", minifyContent("", m))
        r.Post("/css", minifyCss(m))
        r.Post("/html", minifyHtml(m))
        r.Post("/svg", minifySVG(m))
        r.Post("/js", minifyJS(m))
        r.Post("/json", minifyJSON(m))
        r.Post("/xml", minifyXML(m))
    })

    http.ListenAndServe(":3000", r)
}

// Minify godoc
// @Summary      Minify content
// @Description  Minify content based on input type
// @Param input body string false "Input text"
// @Accept       html,text/css,image/svg+xml,application/javascript,json,xml
// @Produce      text/plain
// @Success      200  {string} string "Minified content"
// @Router       / [post]
func minifyContent(mediaType string, min *minify.M) http.HandlerFunc {
    return func(w http.ResponseWriter, r *http.Request) {
        if mediaType == "" {
            mediaType = r.Header.Get("Content-Type")

            if idx := strings.Index(mediaType, ";"); idx != -1 {
                mediaType = mediaType[0:idx]
            }
        }

        _, err := io.Copy(w, min.Reader(mediaType, r.Body))

        if err != nil {
            http.Error(w, err.Error(), http.StatusInternalServerError)
        }
    }
}

// Minify CSS godoc
// @Summary      Minify CSS
// @Description  Minify CSS Input
// @Param input body string false "Input CSS"
// @Accept       text/css
// @Produce      text/css
// @Success      200  {string} string "Minified CSS"
// @Router       /css [post]
func minifyCss(min *minify.M) http.HandlerFunc {
    return minifyContent("text/css", min)
}

// Minify HTML godoc
// @Summary      Minify HTML
// @Description  Minify HTML Input
// @Param input body string false "Input HTML"
// @Accept       html
// @Produce      html
// @Success      200  {string} string "Minified HTML"
// @Router       /html [post]
func minifyHtml(min *minify.M) http.HandlerFunc {
    return minifyContent("text/html", min)
}

// Minify SVG godoc
// @Summary      Minify SVG
// @Description  Minify SVG Input
// @Param input body string false "Input SVG"
// @Accept       image/svg+xml
// @Produce      image/svg+xml
// @Success      200  {string} string "Minified SVG"
// @Router       /svg [post]
func minifySVG(min *minify.M) http.HandlerFunc {
    return minifyContent("image/svg+xml", min)
}

// Minify JS godoc
// @Summary      Minify JavaScript
// @Description  Minify JavaScript Input
// @Param input body string false "Input JavaScript"
// @Accept       application/javascript
// @Produce      application/javascript
// @Success      200  {string} string "Minified JavaScript"
// @Router       /js [post]
func minifyJS(min *minify.M) http.HandlerFunc {
    return minifyContent("application/javascript", min)
}

// Minify JSON godoc
// @Summary      Minify JSON
// @Description  Minify JSON Input
// @Param input body string false "Input JSON"
// @Accept       application/json
// @Produce      application/json
// @Success      200  {string} string "Minified JSON"
// @Router       /json [post]
func minifyJSON(min *minify.M) http.HandlerFunc {
    return minifyContent("application/json", min)
}

// Minify XML godoc
// @Summary      Minify XML
// @Description  Minify XML Input
// @Param input body string false "Input XML"
// @Accept       xml
// @Produce      xml
// @Success      200  {string} string "Minified XML"
// @Router       /xml [post]
func minifyXML(min *minify.M) http.HandlerFunc {
    return minifyContent("text/xml", min)
}