package social

import (
	"context"
	"errors"
	"github.com/google/uuid"
	"github.com/jackc/pgx/v5"
	"pipu/api/internal/api/gen"
	"pipu/api/internal/platform/apperr"
	"strings"
	"unicode/utf8"
)

func validEmoji(s string) bool {
	switch s {
	case "❤️", "👍", "🔥", "😂", "🎵", "👏":
		return true
	}
	return false
}
func (h *Handler) GetChatMeta(ctx context.Context, r gen.GetChatMetaRequestObject) (gen.GetChatMetaResponseObject, error) {
	id, e := userID(ctx)
	if e != nil {
		return nil, e
	}
	tx, e := pairTx(ctx, h.store.pool, id, r.PeerId)
	if e != nil {
		return nil, e
	}
	defer tx.Rollback(ctx)
	if e = allowed(ctx, tx, id, r.PeerId); e != nil {
		return nil, e
	}
	var typing bool
	e = tx.QueryRow(ctx, `SELECT EXISTS(SELECT 1 FROM chat_typing WHERE user_id=$1 AND peer_id=$2 AND expires_at>now())`, r.PeerId, id).Scan(&typing)
	return gen.GetChatMeta200JSONResponse{Typing: typing}, e
}
func (h *Handler) SetChatTyping(ctx context.Context, r gen.SetChatTypingRequestObject) (gen.SetChatTypingResponseObject, error) {
	id, e := userID(ctx)
	if e != nil {
		return nil, e
	}
	if r.Body == nil {
		return nil, invalid()
	}
	tx, e := pairTx(ctx, h.store.pool, id, r.PeerId)
	if e != nil {
		return nil, e
	}
	defer tx.Rollback(ctx)
	if e = allowed(ctx, tx, id, r.PeerId); e != nil {
		return nil, e
	}
	if r.Body.Typing {
		_, e = tx.Exec(ctx, `INSERT INTO chat_typing(user_id,peer_id,expires_at) VALUES($1,$2,now()+interval '6 seconds') ON CONFLICT(user_id,peer_id) DO UPDATE SET expires_at=EXCLUDED.expires_at`, id, r.PeerId)
	} else {
		_, e = tx.Exec(ctx, `DELETE FROM chat_typing WHERE user_id=$1 AND peer_id=$2`, id, r.PeerId)
	}
	if e != nil {
		return nil, e
	}
	return gen.SetChatTyping204Response{}, tx.Commit(ctx)
}
func (h *Handler) UpdateChatMessage(ctx context.Context, r gen.UpdateChatMessageRequestObject) (gen.UpdateChatMessageResponseObject, error) {
	id, e := userID(ctx)
	if e != nil {
		return nil, e
	}
	if r.Body == nil {
		return nil, invalid()
	}
	e = h.store.updateMessage(ctx, id, r.PeerId, r.MessageId, *r.Body)
	return gen.UpdateChatMessage204Response{}, e
}
func (s *Store) updateMessage(ctx context.Context, id, peer, message uuid.UUID, a gen.UpdateChatMessageJSONRequestBody) error {
	tx, e := pairTx(ctx, s.pool, id, peer)
	if e != nil {
		return e
	}
	defer tx.Rollback(ctx)
	if e = allowed(ctx, tx, id, peer); e != nil {
		return e
	}
	var sender uuid.UUID
	var kind string
	var deleted bool
	e = tx.QueryRow(ctx, `SELECT sender_id,attachment_kind,deleted_at IS NOT NULL FROM direct_messages WHERE id=$1 AND LEAST(sender_id,recipient_id)=LEAST($2::uuid,$3::uuid) AND GREATEST(sender_id,recipient_id)=GREATEST($2::uuid,$3::uuid) FOR UPDATE`, message, id, peer).Scan(&sender, &kind, &deleted)
	if errors.Is(e, pgx.ErrNoRows) {
		return apperr.NotFound("social.message_conflict", "message unavailable")
	}
	if e != nil {
		return e
	}
	if a.Action != "react" && sender != id {
		return denied()
	}
	if deleted {
		if a.Action == "delete" {
			return tx.Commit(ctx)
		}
		return apperr.Conflict("social.message_conflict", "message deleted")
	}
	switch a.Action {
	case "edit":
		if a.Text == nil || utf8.RuneCountInString(*a.Text) > 4000 || (kind == "none" && strings.TrimSpace(*a.Text) == "") {
			return invalid()
		}
		_, e = tx.Exec(ctx, `UPDATE direct_messages SET text=$2,edited_at=now() WHERE id=$1`, message, strings.TrimSpace(*a.Text))
	case "delete":
		_, e = tx.Exec(ctx, `UPDATE direct_messages SET text='[deleted]',attachment_kind='none',attachment_id=NULL,deleted_at=now() WHERE id=$1`, message)
		if e == nil {
			_, e = tx.Exec(ctx, `DELETE FROM message_reactions WHERE message_id=$1`, message)
		}
		if e == nil {
			_, e = tx.Exec(ctx, `UPDATE social_notifications SET read_at=COALESCE(read_at,now()) WHERE message_seq=(SELECT seq FROM direct_messages WHERE id=$1)`, message)
		}
	case "react":
		if a.Emoji == nil || !validEmoji(string(*a.Emoji)) {
			return invalid()
		}
		result, err := tx.Exec(ctx, `DELETE FROM message_reactions WHERE message_id=$1 AND user_id=$2 AND emoji=$3`, message, id, *a.Emoji)
		e = err
		if e == nil && result.RowsAffected() == 0 {
			_, e = tx.Exec(ctx, `INSERT INTO message_reactions(message_id,user_id,emoji) VALUES($1,$2,$3)`, message, id, *a.Emoji)
		}
	default:
		return invalid()
	}
	if e != nil {
		return e
	}
	return tx.Commit(ctx)
}
func enrichMessages(ctx context.Context, tx pgx.Tx, viewer uuid.UUID, messages []gen.DirectMessage) error {
	if len(messages) == 0 {
		return nil
	}
	ids := make([]uuid.UUID, 0, len(messages))
	replies := []uuid.UUID{}
	positions := map[uuid.UUID]int{}
	for i, m := range messages {
		ids = append(ids, m.Id)
		positions[m.Id] = i
		if m.ReplyTo != nil {
			replies = append(replies, *m.ReplyTo)
		}
		empty := []gen.MessageReaction{}
		messages[i].Reactions = &empty
	}
	rows, e := tx.Query(ctx, `SELECT message_id,emoji,count(*),bool_or(user_id=$2) FROM message_reactions WHERE message_id=ANY($1::uuid[]) GROUP BY message_id,emoji ORDER BY emoji`, ids, viewer)
	if e != nil {
		return e
	}
	for rows.Next() {
		var id uuid.UUID
		var r gen.MessageReaction
		if e = rows.Scan(&id, &r.Emoji, &r.Count, &r.Mine); e != nil {
			rows.Close()
			return e
		}
		i := positions[id]
		*messages[i].Reactions = append(*messages[i].Reactions, r)
	}
	e = rows.Err()
	rows.Close()
	if e != nil {
		return e
	}
	if len(replies) == 0 {
		return nil
	}
	rows, e = tx.Query(ctx, `SELECT id,CASE WHEN deleted_at IS NULL THEN left(text,160) ELSE '' END FROM direct_messages WHERE id=ANY($1::uuid[])`, replies)
	if e != nil {
		return e
	}
	defer rows.Close()
	previews := map[uuid.UUID]string{}
	for rows.Next() {
		var id uuid.UUID
		var text string
		if e = rows.Scan(&id, &text); e != nil {
			return e
		}
		previews[id] = text
	}
	for i, m := range messages {
		if m.ReplyTo != nil {
			p := previews[*m.ReplyTo]
			messages[i].ReplyPreview = &p
		}
	}
	return rows.Err()
}