package api

import (
	"encoding/json"
	"fmt"
	"net/http"
	"opal/internal/config"
	"os"
	"strings"

	"github.com/gabriel-vasile/mimetype"
)

func RegisterLibraryEndpoints() {
	ProbeLibraries()

	http.HandleFunc("/libraries", EndpointLibraries)
	http.HandleFunc("/libraries/", EndpointLibraryList)
}

type Library struct {
	Name     string `json:"Name"`
	PathName string `json:"PathName"`
	Path     string `json:"-"` //when marshalled, this will be excluded
}

var Libraries []Library

type endpointLibraries struct {
	AvailableLibraries []Library
}

type LibraryListEntry struct {
	Name string
	Type string //file, movie, show, directory, may add more filetypes in future
}

type endpointLibraryList struct {
	LibraryInfo Library
	Listing     []LibraryListEntry
}

func EndpointLibraries(w http.ResponseWriter, r *http.Request) {
	var ret endpointLibraries

	ret.AvailableLibraries = Libraries

	retJson, err := json.Marshal(ret)
	if err != nil {
		fmt.Println("API warning: failed to marshal /libraries response")
		http.Error(w, "Internal server error", http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	w.Write(retJson)
}

// TODO/NON-CRITICAL BUG FIX: web client sends /libraries//{path}/ that then redirects to /libraries/{path}/, should put this comment in the web client code but im too lazy
func EndpointLibraryList(w http.ResponseWriter, r *http.Request) {
	url_split := strings.Split(r.URL.Path, "/")
	if url_split[0] != "" || url_split[1] != "libraries" { //impossible for this to fail unless there is something really wrong
		http.Error(w, "Internal server error", http.StatusInternalServerError)
		return
	}

	if len(url_split) < 4 {
		http.Error(w, "Malformed request", http.StatusBadRequest)
		return
	}

	library_string := url_split[2]
	path := strings.Join(url_split[3:], "/")

	var ret endpointLibraryList

	//TODO: use a map instead
	for _, lib := range Libraries {
		if lib.PathName != library_string {
			continue
		}
		ret.LibraryInfo = lib
	}

	if ret.LibraryInfo.Name == "" { //not found in Libraries because string un-initialised
		http.Error(w, "Malformed request", http.StatusBadRequest) //TODO: library not found (should return 404?)
		return
	}

	//TODO: this is probably a vulnerability
	directoryListing, err := os.ReadDir(ret.LibraryInfo.Path + "/" + path)
	if err != nil {
		fmt.Printf("API warning: potential server error or malicious client: %s\n", err.Error())
		http.Error(w, "Malformed request", http.StatusBadRequest)
		return
	}

	for _, directoryEntry := range directoryListing {
		var entry LibraryListEntry

		if directoryEntry.IsDir() {
			entry.Name = directoryEntry.Name()
			entry.Type = "directory"
		}

		//TODO: update to use opal.cfg files to determine if movie or show
		if directoryEntry.Type().IsRegular() {
			//TODO: formatted string?
			filePath := ret.LibraryInfo.Path + "/" + path + "/" + directoryEntry.Name()
			mtype, err := mimetype.DetectFile(filePath)
			if err != nil {
				http.Error(w, "Internal server error", http.StatusInternalServerError)
				return
			}

			entry.Name = directoryEntry.Name()
			if strings.HasPrefix(mtype.String(), "video/") {
				entry.Type = "video"
			} else {
				entry.Type = "file"
			}
		}

		ret.Listing = append(ret.Listing, entry)
	}

	retJson, err := json.Marshal(ret)
	if err != nil {
		fmt.Printf("API warning: failed to marshal library listing response for %s\n", library_string)
		http.Error(w, "Internal server error", http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	w.Write(retJson)
}

func ProbeLibraries() {
	libraries_config := config.FindNode("/libraries", &config.RootConfigNode)
	if libraries_config == nil {
		fmt.Println("Error: unable to find config node for libraries")
		os.Exit(1)
	}

	for _, child := range libraries_config.Children {
		var lib Library
		lib.Name = config.FetchValue(child.Name, "name", false)
		lib.PathName = config.FetchValue(child.Name, "path_name", false)
		lib.Path = config.FetchValue(child.Name, "path", false)

		if strings.HasPrefix("ERROR", lib.Name) || strings.HasPrefix("ERROR", lib.PathName) {
			fmt.Printf("Error: %s: bad config\n", child.Name)
			os.Exit(1)
		}

		Libraries = append(Libraries, lib)
	}
}