package render

import (
	"github.com/peterqiu0516/sub-store/internal/model"
)

// RenderSurgeProxies renders proxies as Surge text lines.
func RenderSurgeProxies(proxies []model.ProxyNode) (string, error) {
	return RenderTextProxyList(proxies, model.TargetSurge, func(p model.ProxyNode) string {
		return ToSurgeProxyLine(p)
	})
}

// RenderSurgeMacProxies renders proxies as Surge-Mac text lines (adds ssh/h2-connect/snell).
func RenderSurgeMacProxies(proxies []model.ProxyNode) (string, error) {
	return RenderTextProxyList(proxies, model.TargetSurgeMac, func(p model.ProxyNode) string {
		return ToSurgeMacProxyLine(p)
	})
}

// ToSurgeProxyLine converts a single proxy node to a Surge proxy line.
// Returns "" for unsupported proxy types.
func ToSurgeProxyLine(proxy model.ProxyNode) string {
	name := SanitizeTextProxyName(getString(proxy, "name"))
	ptype := getString(proxy, "type")
	server := getString(proxy, "server")
	port := getInt(proxy, "port")

	base := name + "=" + surgeType(proxy) + "," + server + "," + itoa(port)
	entries := CommonTextOptions(proxy)

	switch ptype {
	case "ss":
		entries = unshift(entries,
			[2]any{"encrypt-method", strOr(proxy, "cipher", "none")},
			[2]any{"password", proxy["password"]},
		)
		entries = AppendPluginOptions(entries, proxy, "surge")
		return JoinTextProxy(base, entries)

	case "vmess":
		entries = unshift(entries,
			[2]any{"username", proxy["uuid"]},
			[2]any{"encrypt-method", strOr(proxy, "cipher", "auto")},
			[2]any{"tls", proxy["tls"]},
			[2]any{"sni", proxy["servername"]},
		)
		entries = AppendWsOptions(entries, proxy, "surge")
		return JoinTextProxy(base, entries)

	case "trojan":
		entries = unshift(entries,
			[2]any{"password", proxy["password"]},
			[2]any{"sni", sniOr(proxy, "sni", "servername")},
		)
		return JoinTextProxy(base, entries)

	case "http", "socks5":
		entries = unshift(entries,
			[2]any{"username", proxy["username"]},
			[2]any{"password", proxy["password"]},
			[2]any{"tls", proxy["tls"]},
			[2]any{"sni", sniOr(proxy, "sni", "servername")},
		)
		return JoinTextProxy(base, entries)

	case "hysteria2":
		entries = unshift(entries,
			[2]any{"password", proxy["password"]},
			[2]any{"sni", proxy["sni"]},
		)
		if obfs := proxy["obfs"]; obfs != nil {
			entries = append(entries, [2]any{"obfs", obfs}, [2]any{"obfs-password", proxy["obfs-password"]})
		}
		return JoinTextProxy(base, entries)

	case "tuic":
		entries = unshift(entries,
			[2]any{"uuid", proxy["uuid"]},
			[2]any{"password", proxy["password"]},
			[2]any{"sni", proxy["sni"]},
		)
		return JoinTextProxy(name+"=tuic-v5,"+server+","+itoa(port), entries)

	case "anytls":
		entries = unshift(entries,
			[2]any{"password", proxy["password"]},
			[2]any{"sni", sniOr(proxy, "sni", "servername")},
		)
		return JoinTextProxy(base, entries)

	case "snell":
		entries = unshift(entries,
			[2]any{"psk", pskOrPassword(proxy)},
			[2]any{"version", versionOr3(proxy)},
		)
		return JoinTextProxy(name+"=snell,"+server+","+itoa(port), entries)
	}

	return ""
}

// ToSurgeMacProxyLine adds surge-mac specific types (ssh, h2-connect) on top
// of the base surge line.
func ToSurgeMacProxyLine(proxy model.ProxyNode) string {
	name := SanitizeTextProxyName(getString(proxy, "name"))
	ptype := getString(proxy, "type")
	server := getString(proxy, "server")
	port := getInt(proxy, "port")

	switch ptype {
	case "ssh":
		entries := CommonTextOptions(proxy)
		entries = unshift(entries,
			[2]any{"username", proxy["username"]},
			[2]any{"password", proxy["password"]},
			[2]any{"private-key", proxy["private-key"]},
		)
		return JoinTextProxy(name+"=ssh,"+server+","+itoa(port), entries)

	case "h2-connect":
		entries := CommonTextOptions(proxy)
		entries = unshift(entries,
			[2]any{"username", proxy["username"]},
			[2]any{"password", proxy["password"]},
			[2]any{"tls", proxy["tls"]},
			[2]any{"sni", sniOr(proxy, "sni", "servername")},
		)
		return JoinTextProxy(name+"=h2-connect,"+server+","+itoa(port), entries)
	}

	return ToSurgeProxyLine(proxy)
}

func surgeType(proxy model.ProxyNode) string {
	ptype := getString(proxy, "type")
	if ptype == "socks5" {
		if getBool(proxy, "tls") {
			return "socks5-tls"
		}
		return "socks5"
	}
	if ptype == "http" {
		if getBool(proxy, "tls") {
			return "https"
		}
		return "http"
	}
	return ptype
}

// --- small helpers ---

func unshift(entries [][2]any, front ...[2]any) [][2]any {
	return append(front, entries...)
}

func strOr(proxy model.ProxyNode, key, def string) string {
	s := getString(proxy, key)
	if s == "" {
		return def
	}
	return s
}

func sniOr(proxy model.ProxyNode, keys ...string) any {
	for _, k := range keys {
		if v := proxy[k]; v != nil {
			return v
		}
	}
	return nil
}

func pskOrPassword(proxy model.ProxyNode) any {
	if v := proxy["psk"]; v != nil {
		return v
	}
	return proxy["password"]
}

func versionOr3(proxy model.ProxyNode) any {
	if v := proxy["version"]; v != nil {
		return v
	}
	return 3
}

func itoa(n int) string {
	if n == 0 {
		return "0"
	}
	neg := false
	if n < 0 {
		neg = true
		n = -n
	}
	var buf [20]byte
	i := len(buf)
	for n > 0 {
		i--
		buf[i] = byte('0' + n%10)
		n /= 10
	}
	if neg {
		i--
		buf[i] = '-'
	}
	return string(buf[i:])
}