package logic

import (
	"context"
	"strings"
	"sync"
	"sync/atomic"

	friendentity "spark-server/internal/module/friend/entity"
	"spark-server/internal/module/square/entity"
	userentity "spark-server/internal/module/user/entity"
	"spark-server/internal/pkg/media"

	"go.uber.org/zap"
)

// Repository persists square data. Model implements it.
type Repository interface {
	CreatePost(ctx context.Context, post *entity.Post, audience []int64) error
	CreateBotPost(ctx context.Context, post *entity.Post) error
	GetPost(ctx context.Context, id int64) (*entity.Post, error)
	ListPublicFeed(ctx context.Context, channel entity.Channel, q entity.FeedListQuery) ([]*entity.Post, error)
	ListByAuthor(ctx context.Context, channel entity.Channel, authorID, cursor int64, limit int) ([]*entity.Post, error)
	SoftDeletePost(ctx context.Context, userID, postID int64) (*entity.Post, error)
	SoftDeleteExpiredBotPosts(ctx context.Context, nowMS int64, limit int) ([]*entity.Post, error)
	ListAudience(ctx context.Context, postIDs []int64) (map[int64][]int64, error)
	ListLikes(ctx context.Context, postIDs []int64) (map[int64][]*entity.Like, error)
	AddLike(ctx context.Context, like *entity.Like) (created bool, err error)
	RemoveLike(ctx context.Context, postID, userID int64) error
	ListComments(ctx context.Context, postIDs []int64) (map[int64][]*entity.Comment, error)
	GetComment(ctx context.Context, id int64) (*entity.Comment, error)
	AddComment(ctx context.Context, c *entity.Comment) error
	SoftDeleteComment(ctx context.Context, id int64) error
	CreateNotices(ctx context.Context, rows []*entity.Notice) error
	ListNotices(ctx context.Context, userID int64, channel entity.Channel, cursor int64, limit int) ([]*entity.Notice, error)
	MarkNoticesRead(ctx context.Context, userID int64, channel entity.Channel, cursor int64) error
	GetNoticeState(ctx context.Context, userID int64, channel entity.Channel) (*entity.NoticeState, error)
	LatestNoticeID(ctx context.Context, userID int64, channel entity.Channel) (int64, error)
	AdvanceNoticeRead(ctx context.Context, userID int64, channel entity.Channel, noticeID int64) error
	ListAllByAuthor(ctx context.Context, authorID int64) ([]*entity.Post, error)
	PurgeUser(ctx context.Context, userID int64) error
}

// Friends is the friend graph used for audience and block checks.
type Friends interface {
	AreFriends(ctx context.Context, a, b int64) (bool, error)
	ListBlockedPeerIDs(ctx context.Context, userID int64) ([]int64, error)
	Relation(ctx context.Context, userID, peerID int64) (*friendentity.Relation, error)
	BlockedEither(ctx context.Context, a, b int64) (bool, error)
}

// Users loads profile cards.
type Users interface {
	Get(ctx context.Context, id int64) (*userentity.User, error)
	GetByEmail(ctx context.Context, email string) (*userentity.User, error)
}

// Objects deletes square media. Nil skips GC.
type Objects interface {
	Delete(ctx context.Context, key string) error
}

// IDGen issues Snowflake ids.
type IDGen interface {
	NextID() (int64, error)
}

// Service is the square use-case layer.
type Service struct {
	repo          Repository
	friends       Friends
	users         Users
	objects       Objects
	ids           IDGen
	burst         *burst
	media         media.Policy
	log           *zap.Logger
	discoverMu    sync.Mutex
	discoverReady atomic.Bool
	gate          TextGate
}

func NewService(repo Repository, friends Friends, users Users, objects Objects, ids IDGen) *Service {
	return &Service{repo: repo, friends: friends, users: users, objects: objects, ids: ids, burst: newBurst(), log: zap.NewNop()}
}

// ConfigureMedia sets user-path media detection (bots compress via squarebot MediaCompressor).
func (s *Service) ConfigureMedia(p media.Policy, log *zap.Logger) {
	if s == nil {
		return
	}
	s.media = p
	if log != nil {
		s.log = log
	}
}

func (s *Service) ready() bool {
	return s != nil && s.repo != nil && s.friends != nil && s.users != nil && s.ids != nil
}

// TextGate scans user-authored text. Nil skips the check.
type TextGate interface {
	GateText(ctx context.Context, userID int64, text string) (string, error)
}

// BindModeration wires the shared sensitive-word gate.
func (s *Service) BindModeration(gate TextGate) {
	if s == nil {
		return
	}
	s.gate = gate
}

func (s *Service) gateText(ctx context.Context, userID int64, text string) (string, error) {
	if s == nil || s.gate == nil || strings.TrimSpace(text) == "" {
		return text, nil
	}
	return s.gate.GateText(ctx, userID, text)
}

func normalizeChannel(ch entity.Channel) entity.Channel {
	if ch == "" {
		return entity.ChannelSquare
	}
	return ch
}