package vinegar

import (
	"net/http"
	"path"
	"strings"
)

type (
	FileRoute struct {
		*ServletRoute
		fileRoot string
	}
)

func NewImageRoute(urlPattern string, pathlike string, servlet *Servlet) *FileRoute {
	defaultPrune := strings.Replace(urlPattern, ".*", "", -1)
	rootRoute := NewServletRoute(urlPattern, createUncompressedFileServletFunction(defaultPrune, pathlike, servlet.Cache))
	imgRoute := FileRoute{rootRoute, pathlike}
	return &imgRoute
}

func NewTextRoute(urlPattern string, pathlike string, servlet *Servlet) *FileRoute {
	defaultPrune := strings.Replace(urlPattern, ".*", "", -1)
	rootRoute := NewServletRoute(urlPattern, createCompressibleFileServletFunction(defaultPrune, pathlike, servlet.Cache))
	fr := FileRoute{rootRoute, pathlike}
	return &fr
}

func NewSingleFileRoute(urlPattern string, pathlike string, servlet *Servlet) *FileRoute {
	fun := createSingleFileServletFunction(pathlike)
	route := FileRoute{
		ServletRoute: NewServletRoute("^"+urlPattern+"$", fun),
		fileRoot:     pathlike,
	}
	return &route
}

func createSingleFileServletFunction(pathlike string) ServletHandleFunction {
	cache := NewSingleFileCache(pathlike)
	var fun ServletHandleFunction = func(w http.ResponseWriter, req *http.Request) {
		w.Header().Add(ContentTypeHeaderKey, cache.Mimetype)
		if clientAcceptsGzip(req) {
			w.Header().Add(ContentEncodingHeaderKey, "gzip")
			w.Write(*cache.CompressedContent)
		}
	}

	return fun
}

func createCompressibleFileServletFunction(basePattern string, pathlike string, cache *Lru) ServletHandleFunction {
	var fun ServletHandleFunction = func(w http.ResponseWriter, req *http.Request) {
		stub := strings.Replace(req.URL.Path, basePattern, "", 1)
		cachedContent, exists := cache.Get(stub)
		if !exists {
			content, fileExists := GetDiskContent(path.Join(pathlike, stub))
			if fileExists {
				cache.Put(stub, content)
				cachedContent, _ = cache.Get(stub)
			} else {
				SendError(w, 404, "Oops! Something went wrong.")
				return
			}
		}
		w.Header().Add(ContentTypeHeaderKey, cachedContent.MimeType)
		var err error = nil

		if clientAcceptsGzip(req) {
			w.Header().Add(ContentEncodingHeaderKey, "gzip")
			_, err = w.Write(cachedContent.CompressedContent)
		} else {
			_, err = w.Write(cachedContent.Content)
		}
		if err != nil {
			panic(err)
		}

	}
	return fun
}

func createUncompressedFileServletFunction(basePattern string, pathlike string, cache *Lru) ServletHandleFunction {
	var fun ServletHandleFunction = func(w http.ResponseWriter, req *http.Request) {
		stub := strings.Replace(req.URL.Path, basePattern, "", 1)

		entry, exists := cache.Get(stub)
		if !exists {
			fileContent, fExists := GetDiskContent(path.Join(pathlike, stub))
			if fExists {
				cache.Put(stub, fileContent)
				entry, exists = cache.Get(stub)
			} else {
				SendError(w, 404, "Oops! Something went wrong!")
				return
			}
		}

		if !exists {
			SendError(w, 404, "Oops! Something went wrong.")
		} else {
			_, err := w.Write(entry.Content)
			if err != nil {
				panic(err)
			}
			return
		}
	}
	return fun
}

func clientAcceptsGzip(req *http.Request) bool {
	encodings := req.Header.Get("Accept-Encoding")
	if strings.Contains(encodings, "gzip") {
		return true
	}
	return false
}