package auth

import (
	"context"
	"fmt"
	"sync"
	"time"
)

type Pool struct {
	creds  []*Credential
	cursor int
	mu     sync.Mutex
}

func NewPool(creds []*Credential) *Pool {
	return &Pool{creds: creds}
}

func (p *Pool) Pick() (*Credential, error) {
	p.mu.Lock()
	defer p.mu.Unlock()

	n := len(p.creds)
	if n == 0 {
		return nil, fmt.Errorf("no credentials available")
	}

	for i := 0; i < n; i++ {
		idx := (p.cursor + i) % n
		cred := p.creds[idx]
		if !cred.IsOnCooldown() {
			p.cursor = (idx + 1) % n
			return cred, nil
		}
	}

	return nil, fmt.Errorf("all %d credentials are on cooldown", n)
}

func (p *Pool) MarkFailure(cred *Credential, statusCode int) {
	switch {
	case statusCode == 429:
		cred.SetCooldown(30 * time.Second)
	case statusCode >= 500:
		cred.SetCooldown(5 * time.Second)
	}
}

func (p *Pool) MarkSuccess(cred *Credential) {
	cred.mu.Lock()
	defer cred.mu.Unlock()
	cred.CooldownUntil = time.Time{}
}

func (p *Pool) RefreshExpiring(ctx context.Context) {
	refreshAll(p)
}