package pxndscvm

import (
	"sync"
	"time"

	rl "github.com/yunginnanet/Rate5"
)

// Swamp represents a proxy pool
type Swamp struct {
	// Socks5 is a constant stream of verified Socks5 proxies
	Socks5 chan Proxy
	// Socks4 is a constant stream of verified Socks4 proxies
	Socks4 chan Proxy
	// Socks4a is a constant stream of verified Socks5 proxies
	Socks4a chan Proxy

	// Stats holds the Statistics for our swamp
	Stats *Statistics

	// Pending is a constant stream of proxy strings to be verified
	Pending chan string

	// Birthday represents the time we started checking proxies with this pool
	Birthday time.Time

	scvm     []string
	swampopt *SwampOptions
	started  bool
	mu       *sync.RWMutex
}

var (
	defaultStaleTime = 1 * time.Hour
	defWorkers       = 100
	defaultChecks =  []string{"https://wtfismyip.com/text", "https://myexternalip.com/raw", "https://ipinfo.io/ip"}
)

func defOpt() *SwampOptions {
	return &SwampOptions{
		UserAgents: DefaultUserAgents,
		CheckEndpoints: defaultChecks,
		Stale:      defaultStaleTime,
		MaxWorkers: defWorkers,
		Debug:      false,
	}
}

// SwampOptions holds our configuration for Swamp instances
type SwampOptions struct {
	// UserAgents contains a list of UserAgents to be randomly drawn from for proxied requests, this should be supplied via SetUserAgents
	UserAgents []string
	// Stale is the amount of time since verification that qualifies a proxy going stale.
	// if a stale proxy is drawn during the use of our getter functions, it will be skipped.
	Stale time.Duration
	// Debug when enabled will print results as they come in
	Debug bool
	// CheckEndpoints includes web services that respond with (just) the WAN IP of the connection for validation purposes
	CheckEndpoints []string
	// MaxWorkers determines the maximum amount of workers used for checking proxies
	MaxWorkers int
}

var (
	useProx   *rl.Limiter
	badProx   *rl.Limiter
)

// Proxy represents an individual proxy
type Proxy struct {
	// Endpoint is the address:port of the proxy that we connect to
	Endpoint string
	// ProxiedIP is the address that we end up having when making proxied requests through this proxy
	ProxiedIP string
	// Proto is the version/Protocol (currently SOCKS* only) of the proxy
	Proto string
	// Verified is the time this proxy was last verified working
	Verified time.Time
}

// UniqueKey is an implementation of the Identity interface from Rate5
func (p Proxy) UniqueKey() string {
	return p.Endpoint
}

func init() {
	useProx = rl.NewLimiter(60, 2)
	badProx = rl.NewStrictLimiter(30, 50)
}

// NewDefaultSwamp returns a Swamp with basic options.
func NewDefaultSwamp() *Swamp {
	s := &Swamp{
		Socks5:  make(chan Proxy, 1000),
		Socks4:  make(chan Proxy, 1000),
		Socks4a: make(chan Proxy, 1000),
		Pending: make(chan string, 500),

		Stats: &Statistics{
			Valid4:    0,
			Valid4a:   0,
			Valid5:    0,
			Dispensed: 0,
			mu:        &sync.Mutex{},
		},

		Birthday: time.Now(),

		swampopt: defOpt(),
		mu:       &sync.RWMutex{},
	}

	return s
}