package model

import (
	"context"
	"errors"

	"gorm.io/gorm"

	"spark-server/internal/module/message/entity"
	"spark-server/internal/pkg/errs"
)

func (m *Repo) ListByConversation(ctx context.Context, conversationID, viewerID, lastMsgID int64, limit int) ([]*entity.Message, error) {
	if conversationID <= 0 || viewerID <= 0 {
		return nil, errs.ErrInvalidArgument
	}
	if limit <= 0 {
		limit = 200
	}
	db, err := m.session(ctx)
	if err != nil {
		return nil, err
	}
	kind, err := m.lookupKind(db, conversationID)
	if err != nil {
		return nil, err
	}
	table := tableOf(kind)
	if kind == entity.KindGroup {
		var rows []GroupMessage
		err = db.Table(table).Select(table+".*").
			Joins("LEFT JOIN t_message_deletes AS d ON d.msg_id = "+table+".id AND d.user_id = ?", viewerID).
			Where(table+".conversation_id = ? AND "+table+".id > ? AND "+table+".status <> ? AND d.msg_id IS NULL", conversationID, lastMsgID, entity.StatusHidden).
			Order(table + ".id ASC").
			Limit(limit).
			Find(&rows).Error
		if err != nil {
			return nil, mapDBErr(err)
		}
		out := make([]*entity.Message, 0, len(rows))
		for i := range rows {
			out = append(out, rows[i].entity())
		}
		return out, nil
	}
	var rows []PrivateMessage
	err = db.Table(table).Select(table+".*").
		Joins("LEFT JOIN t_message_deletes AS d ON d.msg_id = "+table+".id AND d.user_id = ?", viewerID).
		Where(table+".conversation_id = ? AND "+table+".id > ? AND "+table+".status <> ? AND d.msg_id IS NULL", conversationID, lastMsgID, entity.StatusHidden).
		Order(table + ".id ASC").
		Limit(limit).
		Find(&rows).Error
	if err != nil {
		return nil, mapDBErr(err)
	}
	out := make([]*entity.Message, 0, len(rows))
	for i := range rows {
		out = append(out, rows[i].entity())
	}
	return out, nil
}

func (m *Repo) Recall(ctx context.Context, id int64) error {
	if id <= 0 {
		return errs.ErrInvalidArgument
	}
	db, err := m.session(ctx)
	if err != nil {
		return err
	}
	if n, err := m.recallTable(db, tablePrivateMessage, id); err != nil {
		return err
	} else if n > 0 {
		return nil
	}
	n, err := m.recallTable(db, tableGroupMessage, id)
	if err != nil {
		return err
	}
	if n == 0 {
		return errs.ErrNotFound
	}
	return nil
}

func (m *Repo) recallTable(db *gorm.DB, table string, id int64) (int64, error) {
	res := db.Table(table).Where("id = ? AND status = ?", id, entity.StatusNormal).Update("status", entity.StatusRecalled)
	if res.Error != nil {
		return 0, mapDBErr(res.Error)
	}
	return res.RowsAffected, nil
}

func (m *Repo) HideForUser(ctx context.Context, userID int64, msg *entity.Message) error {
	if userID <= 0 || msg == nil || msg.ID <= 0 {
		return errs.ErrInvalidArgument
	}
	db, err := m.session(ctx)
	if err != nil {
		return err
	}
	row := MessageDelete{
		UserID: userID, MsgID: msg.ID, ConversationID: msg.ConversationID,
	}
	if err := db.Create(&row).Error; err != nil {
		if errors.Is(mapDBErr(err), errs.ErrDuplicate) {
			return nil
		}
		return mapDBErr(err)
	}
	return nil
}

func (m *Repo) PurgeUser(ctx context.Context, userID int64) error {
	if userID <= 0 {
		return errs.ErrInvalidArgument
	}
	db, err := m.session(ctx)
	if err != nil {
		return err
	}
	return mapDBErr(db.Where("user_id = ?", userID).Delete(&MessageDelete{}).Error)
}