package main

import (
	"context"
	"database/sql"
	"flag"
	"fmt"
	"log"
	"os"
	"os/signal"
	"syscall"
	"time"

	"github.com/cosmic-clash/cosmic-clash/server/domain"
	"github.com/cosmic-clash/cosmic-clash/server/matcher"
	"github.com/cosmic-clash/cosmic-clash/server/migrations"
	"github.com/cosmic-clash/cosmic-clash/server/store"
	_ "github.com/jackc/pgx/v5/stdlib"
)

func main() {
	dsn := flag.String("dsn", os.Getenv("COSMIC_CLASH_POSTGRES_DSN"), "PostgreSQL connection string")
	migrationDir := flag.String("migrations", "migrations", "directory containing numbered SQL migrations")
	playlist := flag.String("playlist", string(domain.Casual), "playlist to match; ranked requires a provider-enabled role")
	size := flag.Int("size", 4, "players per match")
	interval := flag.Duration("interval", time.Second, "poll interval")
	flag.Parse()
	if *dsn == "" {
		fatalf("--dsn or COSMIC_CLASH_POSTGRES_DSN is required")
	}
	if *playlist != string(domain.Casual) {
		fatalf("unsupported playlist %q; only casual is currently enabled", *playlist)
	}
	db, err := sql.Open("pgx", *dsn)
	if err != nil {
		fatalf("open PostgreSQL: %v", err)
	}
	defer db.Close()
	startupCtx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
	defer cancel()
	if err := db.PingContext(startupCtx); err != nil {
		fatalf("ping PostgreSQL: %v", err)
	}
	if err := migrations.Apply(startupCtx, db, *migrationDir); err != nil {
		fatalf("apply migrations: %v", err)
	}
	now := func() time.Time { return time.Now().UTC() }
	worker := matcher.Worker{
		Source: func(ctx context.Context, at time.Time, playlist domain.Playlist, limit int) ([]domain.Candidate, error) {
			return store.ListQueuedCandidates(ctx, db, playlist, at, limit)
		},
		Creator: matcher.ProposalCreatorFunc(func(ctx context.Context, proposal domain.Proposal, ticketIDs map[string]string, at time.Time) error {
			return store.CreateProposal(ctx, db, proposal, ticketIDs, at)
		}),
		Playlist: domain.Casual, Size: *size, Now: now,
		NextID: func() string { return fmt.Sprintf("proposal-%d", time.Now().UnixNano()) },
		Prepare: func(id string, playlist domain.Playlist, formation domain.MatchFormation, at time.Time) (domain.PreparedProposal, error) {
			return domain.PrepareProposal(id, playlist, formation, nil, domain.RankedArena{}, at)
		},
	}
	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
	defer stop()
	if err := worker.Run(ctx, *interval); err != nil && ctx.Err() == nil {
		fatalf("matcher stopped: %v", err)
	}
}

func fatalf(format string, args ...any) {
	log.Printf("matcher: "+format, args...)
	os.Exit(1)
}