package httpRequest

import (
	"encoding/json"
	"maps"
	"net/http"
	"slices"
	"strings"
	"time"

	"go-socket/packages/cache"
	"go-socket/packages/types"
	"go-socket/packages/wsServer"

	"github.com/google/uuid"
)

func haveHubUserPermission(u *types.HubUser, h *types.Hub, needed types.Permissions) bool {
	h.Mu.Lock()
	defer h.Mu.Unlock()
	for _, role := range h.Roles {
		if role == nil {
			continue
		}
		if !u.Roles.Has(role.Id) {
			continue
		}
		if (needed & role.Permissions) == needed {
			return true
		}
	}
	return false
}

func haveHubUserCachedPermissions(needed types.CachedUserPermissions, user *types.HubUser, channel *types.HubChannel) bool {
	channel.Mu.RLock()
	checkAgainst, ok := channel.UsersCachedPermissions[user.OriginalId]
	channel.Mu.RUnlock()
	if !ok || (needed&checkAgainst) != needed {
		return false
	}
	return true
}

func HandleHubCreate(response http.ResponseWriter, request *http.Request) {
	if !validCheckWithResponseOnFail(&response, request, normal) {
		return
	}

	ctx := request.Context()
	user, err := getUserByToken(ctx, request.Header.Get("token"))
	if err != nil {
		http.Error(response, "invalid token", http.StatusUnauthorized)
		return
	}

	hubName := request.FormValue("hubname")
	if hubName == "" {
		http.Error(response, "hub name is required", http.StatusBadRequest)
		return
	}

	hub := types.NewHub()
	hub.Name = hubName
	hub.Color = types.Rgba{}.GetRandom()
	hub.Id = uuid.New()
	hub.Creator = user.Id
	hub.CreatedAt = time.Now()
	user.Hubs[user.Id] = hub

	creator := types.NewHubUser()
	creator.OriginalId = user.Id
	creator.CreatedAt = hub.CreatedAt
	hub.Users[creator.OriginalId] = creator

	rootRole := &types.HubRole{
		Id:          uint8(0),
		Permissions: types.PermissionAll(),
		Name:        "root",
		Color:       types.Rgba{}.GetRandom(),
		CreatedAt:   hub.CreatedAt,
	}
	hub.Roles[rootRole.Id] = rootRole
	creator.Roles.Add(rootRole.Id)

	memberRole := &types.HubRole{
		Id:        types.HubBoundRolesMax,
		Name:      "member",
		Color:     types.Rgba{}.GetRandom(),
		CreatedAt: hub.CreatedAt,
	}
	hub.JoinRole = memberRole
	hub.Roles[memberRole.Id] = memberRole
	creator.Roles.Add(memberRole.Id)

	channel := types.NewHubChannel()
	channel.Name = "main channel"
	channel.Position = uint8(0)
	channel.Id = uuid.New()
	channel.Description = "The fist channel!"
	channel.CreatedAt = hub.CreatedAt
	channel.RolesCanMessage.Add(rootRole.Id)
	channel.RolesCanMessage.Add(memberRole.Id)
	channel.RolesCanView.Add(rootRole.Id)
	channel.RolesCanView.Add(memberRole.Id)
	channel.RolesCanReadHistory.Add(rootRole.Id)
	channel.RolesCanReadHistory.Add(memberRole.Id)
	channel.UsersCachedPermissions[creator.OriginalId] = types.CachedUserPermissionsAll
	hub.Channels[channel.Id] = channel

	cache.SaveHub(hub)
}

func HandleHubJoin(response http.ResponseWriter, request *http.Request) {
	if !validCheckWithResponseOnFail(&response, request, normal) {
		return
	}
	ctx := request.Context()
	user, err := getUserByToken(ctx, request.Header.Get("token"))
	if err != nil {
		http.Error(response, "invalid token", http.StatusBadRequest)
		return
	}
	hub, err := getHubByIdStr(ctx, request.Header.Get("hubid"))
	if err != nil {
		http.Error(response, "invalid hubid", http.StatusBadRequest)
		return
	}

	hubUser := types.NewHubUser()
	hubUser.OriginalId = user.Id
	hubUser.Roles.Add(hub.JoinRole.Id)
	hubUser.CreatedAt = time.Now()
	hub.Users[hubUser.OriginalId] = hubUser
}

func HandleHubMessage(response http.ResponseWriter, request *http.Request) {
	if !validCheckWithResponseOnFail(&response, request, normal) {
		return
	}
	ctx := request.Context()
	user, hubUser, hub, err := getHubUserIfValidWithResponseOnFail(ctx, response, request)
	if err != nil {
		return
	}
	channel, err := getHubChannelIfValidWithResponseOnFail(ctx, response, hub, hubUser, request.Header.Get("channelid"))
	if err != nil {
		return
	}

	if hubUser.IsMuted {
		http.Error(response, "muted", http.StatusForbidden)
	}

	msgContent := request.FormValue("msgContent")
	attachedFile := request.FormValue("attachedFile")

	if msgContent == "" && attachedFile == "" {
		http.Error(response, "empty msgContent", http.StatusBadRequest)
		return
	}

	if attachedFile != "" && !strings.HasPrefix(attachedFile, channel.Id.String()+"/") {
		http.Error(response, "invalid attachedFile", http.StatusBadRequest)
		return
	}

	channel.Mu.RLock()
	perms := channel.UsersCachedPermissions
	channel.Mu.RUnlock()

	msg := &types.Message{
		Id:           uuid.New(),
		AttachedFile: attachedFile,
		Content:      msgContent,
		Sender:       user.Id,
		Receiver:     channel.Id,
		CreatedAt:    time.Now(),
	}

	for permId, perm := range perms {
		if !perm.CanReadHistory() {
			continue
		}

		target, err := cache.GetUserById(permId)
		if err != nil {
			continue
		}
		wsServer.WsSendMessageCloseIfTimeout(target, msg)
	}
}

func HandleGetHubs(response http.ResponseWriter, request *http.Request) {
	if !validCheckWithResponseOnFail(&response, request, normal) {
		return
	}
	ctx := request.Context()
	user, err := getUserByToken(ctx, request.Header.Get("token"))
	if err != nil {
		http.Error(response, "invalid token", http.StatusBadRequest)
		return
	}

	user.Mu.RLock()
	hubs := slices.Collect(maps.Values(user.Hubs))
	user.Mu.RUnlock()
	if len(hubs) == 0 {
		response.WriteHeader(http.StatusNoContent)
		response.Write([]byte("no hubs found"))
	}
	converted, err := json.Marshal(hubs)
	if err != nil {
		http.Error(response, "json error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusOK)
	response.Write(converted)
}

func HandleHubPermissionActionCore(
	response http.ResponseWriter, request *http.Request,
	takenVarName string, rt requestType, needed types.Permissions,
	performedAction func(usr *types.HubUser, hub *types.Hub, takenVar *string)) {
	if !validCheckWithResponseOnFail(&response, request, rt) {
		return
	}
	ctx := request.Context()
	_, hubUser, hub, err := getHubUserIfValidWithResponseOnFail(ctx, response, request)
	if err != nil {
		return
	}

	if !haveHubUserPermission(hubUser, hub, needed) {
		http.Error(response, "", http.StatusForbidden)
	}

	var takenVar *string = nil

	if takenVarName != "" {
		takenVar = new(request.FormValue(takenVarName))
	}
	performedAction(hubUser, hub, takenVar)
}

func HandleHubSetName(response http.ResponseWriter, request *http.Request) {
	HandleHubPermissionActionCore(response, request, "newname", normal, types.PermissionSetHubName, func(usr *types.HubUser, hub *types.Hub, takenVar *string) {
		newName := *takenVar
		if newName == "" {
			http.Error(response, "empty name", http.StatusBadRequest)
			return
		}
		hub.Name = newName
	})
}