package appservice

import (
	"maunium.net/go/gomatrix"
	"sync"
	"time"
)

type StateStore interface {
	IsRegistered(userID string) bool
	MarkRegistered(userID string)

	IsTyping(roomID, userID string) bool
	SetTyping(roomID, userID string, timeout int64)

	IsInRoom(roomID, userID string) bool
	IsInvited(roomID, userID string) bool
	IsMembership(roomID, userID string, allowedMemberships ...gomatrix.Membership) bool
	SetMembership(roomID, userID string, membership gomatrix.Membership)

	SetPowerLevels(roomID string, levels *gomatrix.PowerLevels)
	GetPowerLevels(roomID string) *gomatrix.PowerLevels
	GetPowerLevel(roomID, userID string) int
	GetPowerLevelRequirement(roomID string, eventType gomatrix.EventType) int
	HasPowerLevel(roomID, userID string, eventType gomatrix.EventType) bool
}

func (as *AppService) UpdateState(evt *gomatrix.Event) {
	switch evt.Type {
	case gomatrix.StateMember:
		as.StateStore.SetMembership(evt.RoomID, evt.GetStateKey(), evt.Content.Membership)
	case gomatrix.StatePowerLevels:
		as.StateStore.SetPowerLevels(evt.RoomID, &evt.Content.PowerLevels)
	}
}

type BasicStateStore struct {
	registrationsLock sync.RWMutex                              `json:"-"`
	Registrations     map[string]bool                           `json:"registrations"`
	membershipsLock   sync.RWMutex                              `json:"-"`
	Memberships       map[string]map[string]gomatrix.Membership `json:"memberships"`
	powerLevelsLock   sync.RWMutex                              `json:"-"`
	PowerLevels       map[string]*gomatrix.PowerLevels          `json:"power_levels"`

	Typing     map[string]map[string]int64 `json:"-"`
	typingLock sync.RWMutex                `json:"-"`
}

func NewBasicStateStore() StateStore {
	return &BasicStateStore{
		Registrations: make(map[string]bool),
		Memberships:   make(map[string]map[string]gomatrix.Membership),
		PowerLevels:   make(map[string]*gomatrix.PowerLevels),
		Typing:        make(map[string]map[string]int64),
	}
}

func (store *BasicStateStore) IsRegistered(userID string) bool {
	store.registrationsLock.RLock()
	defer store.registrationsLock.RUnlock()
	registered, ok := store.Registrations[userID]
	return ok && registered
}

func (store *BasicStateStore) MarkRegistered(userID string) {
	store.registrationsLock.Lock()
	defer store.registrationsLock.Unlock()
	store.Registrations[userID] = true
}

func (store *BasicStateStore) IsTyping(roomID, userID string) bool {
	store.typingLock.RLock()
	defer store.typingLock.RUnlock()
	roomTyping, ok := store.Typing[roomID]
	if !ok {
		return false
	}
	typingEndsAt, _ := roomTyping[userID]
	return typingEndsAt >= time.Now().Unix()
}

func (store *BasicStateStore) SetTyping(roomID, userID string, timeout int64) {
	store.typingLock.Lock()
	defer store.typingLock.Unlock()
	roomTyping, ok := store.Typing[roomID]
	if !ok {
		if timeout >= 0 {
			roomTyping = map[string]int64{
				userID: time.Now().Unix() + timeout,
			}
		} else {
			roomTyping = make(map[string]int64)
		}
	} else {
		if timeout >= 0 {
			roomTyping[userID] = time.Now().Unix() + timeout
		} else {
			delete(roomTyping, userID)
		}
	}
	store.Typing[roomID] = roomTyping
}

func (store *BasicStateStore) GetRoomMemberships(roomID string) map[string]gomatrix.Membership {
	store.membershipsLock.RLock()
	memberships, ok := store.Memberships[roomID]
	store.membershipsLock.RUnlock()
	if !ok {
		memberships = make(map[string]gomatrix.Membership)
		store.membershipsLock.Lock()
		store.Memberships[roomID] = memberships
		store.membershipsLock.Unlock()
	}
	return memberships
}

func (store *BasicStateStore) GetMembership(roomID, userID string) gomatrix.Membership {
	store.membershipsLock.RLock()
	defer store.membershipsLock.RUnlock()
	memberships, ok := store.Memberships[roomID]
	if !ok {
		return gomatrix.MembershipLeave
	}
	membership, ok := memberships[userID]
	if !ok {
		return gomatrix.MembershipLeave
	}
	return membership
}

func (store *BasicStateStore) IsInRoom(roomID, userID string) bool {
	return store.IsMembership(roomID, userID, "join")
}

func (store *BasicStateStore) IsInvited(roomID, userID string) bool {
	return store.IsMembership(roomID, userID, "join", "invite")
}

func (store *BasicStateStore) IsMembership(roomID, userID string, allowedMemberships ...gomatrix.Membership) bool {
	membership := store.GetMembership(roomID, userID)
	for _, allowedMembership := range allowedMemberships {
		if allowedMembership == membership {
			return true
		}
	}
	return false
}

func (store *BasicStateStore) SetMembership(roomID, userID string, membership gomatrix.Membership) {
	store.membershipsLock.Lock()
	memberships, ok := store.Memberships[roomID]
	if !ok {
		memberships = map[string]gomatrix.Membership{
			userID: membership,
		}
	} else {
		memberships[userID] = membership
	}
	store.Memberships[roomID] = memberships
	store.membershipsLock.Unlock()
}

func (store *BasicStateStore) SetPowerLevels(roomID string, levels *gomatrix.PowerLevels) {
	store.powerLevelsLock.Lock()
	store.PowerLevels[roomID] = levels
	store.powerLevelsLock.Unlock()
}

func (store *BasicStateStore) GetPowerLevels(roomID string) (levels *gomatrix.PowerLevels) {
	store.powerLevelsLock.RLock()
	levels, _ = store.PowerLevels[roomID]
	store.powerLevelsLock.RUnlock()
	return
}

func (store *BasicStateStore) GetPowerLevel(roomID, userID string) int {
	return store.GetPowerLevels(roomID).GetUserLevel(userID)
}

func (store *BasicStateStore) GetPowerLevelRequirement(roomID string, eventType gomatrix.EventType) int {
	return store.GetPowerLevels(roomID).GetEventLevel(eventType)
}

func (store *BasicStateStore) HasPowerLevel(roomID, userID string, eventType gomatrix.EventType) bool {
	return store.GetPowerLevel(roomID, userID) >= store.GetPowerLevelRequirement(roomID, eventType)
}