package agents

import (
	"context"
	"fmt"
	"sort"
	"strings"
	"time"

	"g.fc.run/ai/byre/internal/api"
	"g.fc.run/ai/byre/internal/clients"
)

const signTimeout = 2 * time.Minute

func (m *Manager) signer(ctx context.Context, user api.User) func(payload []byte) ([]byte, error) {
	return func(payload []byte) ([]byte, error) {
		mine := []clients.Client{}
		for _, c := range m.clients.List() {
			if c.Login == user.Login {
				mine = append(mine, c)
			}
		}
		if len(mine) == 0 {
			return nil, fmt.Errorf("commits are signed on %s's Mac, and none of theirs is connected", user.Login)
		}
		sort.SliceStable(mine, func(i, j int) bool {
			a, b := mine[i].LastActionAt, mine[j].LastActionAt
			return a != nil && (b == nil || a.After(*b))
		})
		client := mine[0]

		ident := fmt.Sprintf("%s <%s>", user.GitName, user.GitEmail)
		ms := int(signTimeout.Milliseconds())
		cctx, cancel := context.WithTimeout(ctx, signTimeout+replyGrace)
		defer cancel()
		reply, err := m.clients.Call(cctx, client.ID, api.ClientRequest{Op: api.Sign, Data: &payload, Ident: &ident, TimeoutMs: &ms})
		if err != nil {
			return nil, err
		}
		if reply.ExitCode == nil || reply.Output == nil || reply.Data == nil {
			return nil, fmt.Errorf("%s's reply has no exit_code, output or data", client.Host)
		}
		if *reply.ExitCode == -1 {
			return nil, fmt.Errorf("%s didn't sign within %s", client.Host, signTimeout)
		}
		if *reply.ExitCode != 0 || !strings.Contains(*reply.Output, "[GNUPG:] SIG_CREATED ") {
			return nil, fmt.Errorf("signing on %s failed with exit status %d: %s", client.Host, *reply.ExitCode, strings.TrimSpace(*reply.Output))
		}
		return *reply.Data, nil
	}
}