package main

import (
	"context"
	"database/sql"
	"encoding/json"

	"github.com/heroiclabs/nakama-common/runtime"
)

type FindMatchRequest struct{}

type FindMatchResponse struct {
	MatchID string `json:"match_id"`
}

func rpcFindMatch(
	ctx context.Context,
	logger runtime.Logger,
	db *sql.DB,
	nk runtime.NakamaModule,
	payload string,
) (string, error) {

	logger.Info("rpc_find_match called")

	var req FindMatchRequest
	if payload != "" {
		if err := json.Unmarshal([]byte(payload), &req); err != nil {
			logger.Warn("rpc_find_match: invalid request payload: %v", err)
		}
	}

	const limit = 10
	authoritative := true
	labelFilter := "tictactoe" // must match MatchInit label
	var minSize, maxSize *int  // nil = no constraint

	matches, err := nk.MatchList(
		ctx,
		limit,
		authoritative,
		labelFilter,
		minSize,
		maxSize,
		"", // query
	)
	if err != nil {
		logger.Error("rpc_find_match: MatchList failed: %v", err)
		return "", runtime.NewError("internal error", 13)
	}

	for _, m := range matches {
		if m.Size < 2 {
			logger.Info("rpc_find_match: found match %s with size=%d", m.MatchId, m.Size)
			out, _ := json.Marshal(FindMatchResponse{MatchID: m.MatchId})
			return string(out), nil
		}
	}

	matchID, err := nk.MatchCreate(ctx, "tictactoe", map[string]interface{}{})
	if err != nil {
		logger.Error("rpc_find_match: MatchCreate failed: %v", err)
		return "", runtime.NewError("internal error", 13)
	}

	logger.Info("rpc_find_match: created new match %s", matchID)
	out, _ := json.Marshal(FindMatchResponse{MatchID: matchID})
	return string(out), nil
}