package config

import "fmt"

// TCDevice defines a traffic-shaped interface with bandwidth limits.
type TCDevice struct {
	Interface    string          `yaml:"interface"`
	InBandwidth  string          `yaml:"in_bandwidth,omitempty"` // ingress rate limit
	OutBandwidth string          `yaml:"out_bandwidth"`          // egress max
	Options      TCDeviceOptions `yaml:"options,omitempty"`
	Comment      string          `yaml:"comment,omitempty"`
}

type TCDeviceOptions struct {
	Classify  bool   `yaml:"classify,omitempty"`
	HTB       bool   `yaml:"htb,omitempty"`
	HFSC      bool   `yaml:"hfsc,omitempty"`
	Linklayer string `yaml:"linklayer,omitempty"` // ethernet, atm, adsl
}

// TCClass defines an HTB/HFSC traffic class with rate guarantees.
type TCClass struct {
	Interface string         `yaml:"interface"`          // format: iface:class or iface:parent:class
	Mark      int            `yaml:"mark,omitempty"`     // 1-255 fw mark
	Rate      string         `yaml:"rate"`               // minimum guaranteed bandwidth
	Ceil      string         `yaml:"ceil,omitempty"`     // max bandwidth
	Priority  int            `yaml:"priority,omitempty"` // scheduling order
	Options   TCClassOptions `yaml:"options,omitempty"`
	Comment   string         `yaml:"comment,omitempty"`
}

type TCClassOptions struct {
	Default bool `yaml:"default,omitempty"` // default class for unclassified traffic
	TCPAck  bool `yaml:"tcp_ack,omitempty"`
	Pfifo   bool `yaml:"pfifo,omitempty"`
}

// TCFilter classifies packets into traffic classes.
type TCFilter struct {
	Class    string   `yaml:"class"` // interface:class
	Source   string   `yaml:"source,omitempty"`
	Dest     string   `yaml:"dest,omitempty"`
	Proto    string   `yaml:"proto,omitempty"`
	DPort    PortSpec `yaml:"dport,omitempty"`
	SPort    PortSpec `yaml:"sport,omitempty"`
	TOS      string   `yaml:"tos,omitempty"`
	Length   int      `yaml:"length,omitempty"`
	Priority int      `yaml:"priority,omitempty"` // filter eval order
	Comment  string   `yaml:"comment,omitempty"`
}

// TCInterface defines simple traffic shaping (3-band priority queueing).
type TCInterface struct {
	Interface    string `yaml:"interface"`
	Type         string `yaml:"type,omitempty"` // external, internal
	InBandwidth  string `yaml:"in_bandwidth,omitempty"`
	OutBandwidth string `yaml:"out_bandwidth,omitempty"`
	Comment      string `yaml:"comment,omitempty"`
}

// TCPriority assigns packets to priority bands (1=high, 2=medium, 3=low).
type TCPriority struct {
	Band      int      `yaml:"band"` // 1, 2, or 3
	Proto     string   `yaml:"proto,omitempty"`
	DPort     PortSpec `yaml:"dport,omitempty"`
	SPort     PortSpec `yaml:"sport,omitempty"`
	Address   string   `yaml:"address,omitempty"`
	Interface string   `yaml:"interface,omitempty"`
	Helper    string   `yaml:"helper,omitempty"`
	Comment   string   `yaml:"comment,omitempty"`
}

func (c *Config) validateTCDevices() error {
	for i, dev := range c.TCDevices {
		if dev.Interface == "" {
			return fmt.Errorf("tcdevices[%d]: interface required", i)
		}
		if dev.OutBandwidth == "" {
			return fmt.Errorf("tcdevices[%d]: out_bandwidth required", i)
		}
	}
	return nil
}

func (c *Config) validateTCClasses() error {
	for i, cls := range c.TCClasses {
		if cls.Interface == "" {
			return fmt.Errorf("tcclasses[%d]: interface required", i)
		}
		if cls.Rate == "" {
			return fmt.Errorf("tcclasses[%d]: rate required", i)
		}
		if cls.Mark != 0 && (cls.Mark < 1 || cls.Mark > 255) {
			return fmt.Errorf("tcclasses[%d]: mark must be 1-255", i)
		}
	}
	return nil
}

func (c *Config) validateTCFilters() error {
	for i, f := range c.TCFilters {
		if f.Class == "" {
			return fmt.Errorf("tcfilters[%d]: class required", i)
		}
		if f.Source == "" && f.Dest == "" {
			return fmt.Errorf("tcfilters[%d]: source or dest required", i)
		}
	}
	return nil
}

func (c *Config) validateTCInterfaces() error {
	for i, iface := range c.TCInterfaces {
		if iface.Interface == "" {
			return fmt.Errorf("tcinterfaces[%d]: interface required", i)
		}
	}
	return nil
}

func (c *Config) validateTCPriority() error {
	for i, p := range c.TCPriorities {
		if p.Band < 1 || p.Band > 3 {
			return fmt.Errorf("tcpriority[%d]: band must be 1, 2, or 3", i)
		}
	}
	return nil
}