package safew

import (
	"context"
	"sync"
	"time"

	"aiaa-notification-service/internal/adapter"
)

type ChatStore interface {
	MergeSafewChats(ctx context.Context, token string, chats []adapter.SafewChat) error
	ListSafewChats(ctx context.Context, token string) ([]adapter.SafewChat, error)
	GetSafewOffset(ctx context.Context, token string) (int64, error)
	SetSafewOffset(ctx context.Context, token string, offset int64) error
	TrySafewPollLock(ctx context.Context, token string, ttl time.Duration) (bool, error)
	UnlockSafewPoll(ctx context.Context, token string) error
}

type MemStore struct {
	mu     sync.Mutex
	chats  map[string]map[string]adapter.SafewChat
	offset map[string]int64
	locks  map[string]bool
}

func NewMemStore() *MemStore {
	return &MemStore{
		chats:  map[string]map[string]adapter.SafewChat{},
		offset: map[string]int64{},
		locks:  map[string]bool{},
	}
}

func (m *MemStore) MergeSafewChats(_ context.Context, token string, chats []adapter.SafewChat) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	if m.chats[token] == nil {
		m.chats[token] = map[string]adapter.SafewChat{}
	}
	for _, c := range chats {
		m.chats[token][c.ID] = c
	}
	return nil
}

func (m *MemStore) ListSafewChats(_ context.Context, token string) ([]adapter.SafewChat, error) {
	m.mu.Lock()
	defer m.mu.Unlock()
	var out []adapter.SafewChat
	for _, c := range m.chats[token] {
		out = append(out, c)
	}
	if out == nil {
		out = []adapter.SafewChat{}
	}
	return out, nil
}

func (m *MemStore) GetSafewOffset(_ context.Context, token string) (int64, error) {
	m.mu.Lock()
	defer m.mu.Unlock()
	return m.offset[token], nil
}

func (m *MemStore) SetSafewOffset(_ context.Context, token string, offset int64) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	m.offset[token] = offset
	return nil
}

func (m *MemStore) TrySafewPollLock(_ context.Context, token string, _ time.Duration) (bool, error) {
	m.mu.Lock()
	defer m.mu.Unlock()
	if m.locks[token] {
		return false, nil
	}
	m.locks[token] = true
	return true, nil
}

func (m *MemStore) UnlockSafewPoll(_ context.Context, token string) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	delete(m.locks, token)
	return nil
}