package config

import (
	"crypto/sha1"
	"encoding/gob"
	"encoding/hex"
	"net/http"
	"path/filepath"

	"github.com/Neur0toxine/sshpoke/pkg/smarttypes"
	"github.com/docker/docker/client"
	"github.com/docker/go-connections/tlsconfig"
)

var (
	Default    Config
	configHash string
)

type Config struct {
	Debug         bool         `mapstructure:"debug" json:"debug"`
	API           API          `mapstructure:"api" json:"api"`
	Docker        DockerConfig `mapstructure:"docker" json:"docker"`
	DefaultServer string       `mapstructure:"default_server" json:"default_server"`
	Services      []Service    `mapstructure:"services" json:"services,omitempty"`
	Servers       []Server     `mapstructure:"servers" json:"servers"`
}

func HasBeenUpdated() bool {
	return generateConfigHash() != configHash
}

func Rehash() {
	configHash = generateConfigHash()
}

func generateConfigHash() string {
	h := sha1.New()
	_ = gob.NewEncoder(h).Encode(Default)
	return hex.EncodeToString(h.Sum(nil))
}

type Service struct {
	Name   smarttypes.MatchableString `mapstructure:"name" json:"name"`
	Params ServiceLabels              `mapstructure:"params" json:"params"`
}

type ServiceLabels struct {
	Enable     smarttypes.BoolStr `mapstructure:"enable" json:"enable"`
	Network    string             `mapstructure:"network" json:"network,omitempty"`
	Server     string             `mapstructure:"server" json:"server,omitempty"`
	Port       string             `mapstructure:"port" json:"port,omitempty"`
	RemoteHost string             `mapstructure:"remote_host" json:"remote_host,omitempty"`
}

type API struct {
	Rest   WebAPI    `mapstructure:"rest" json:"rest"`
	Plugin PluginAPI `mapstructure:"plugin" json:"plugin"`
}

type WebAPI struct {
	Port  int    `mapstructure:"port" json:"port" validate:"gte=0,lte=65535"`
	Token string `mapstructure:"token" json:"token"`
}

type PluginAPI struct {
	Port int `mapstructure:"port" json:"port" validate:"gte=0,lte=65535"`
}

type DockerConfig struct {
	FromEnv   *bool  `mapstructure:"from_env,omitempty" json:"from_env"`
	CertPath  string `mapstructure:"cert_path" json:"cert_path,omitempty"`
	TLSVerify *bool  `mapstructure:"tls_verify,omitempty" json:"tls_verify,omitempty"`
	Host      string `mapstructure:"host" json:"host,omitempty"`
	Version   string `mapstructure:"version" json:"version,omitempty"`
}

type DriverParams map[string]interface{}

type DriverType string

const (
	DriverSSH    DriverType = "ssh"
	DriverPlugin DriverType = "plugin"
	DriverNil    DriverType = "nil"
)

type Server struct {
	Name   string       `mapstructure:"name" json:"name" validate:"required"`
	Driver DriverType   `mapstructure:"driver" json:"driver"`
	Params DriverParams `mapstructure:"params" json:"params,omitempty"`
}

func (d DockerConfig) Opts(c *client.Client) error {
	if d.FromEnv == nil || *d.FromEnv {
		return client.FromEnv(c)
	}
	ops := []client.Opt{
		d.withTLSClientConfig(),
		d.withHost(),
		d.withVersion(),
	}
	for _, op := range ops {
		if err := op(c); err != nil {
			return err
		}
	}
	return nil
}

func (d DockerConfig) withTLSClientConfig() client.Opt {
	return func(c *client.Client) error {
		dockerCertPath := d.CertPath
		if dockerCertPath == "" {
			return nil
		}
		skipTLSVerify := false
		if d.TLSVerify != nil && !(*d.TLSVerify) {
			skipTLSVerify = true
		}
		options := tlsconfig.Options{
			CAFile:             filepath.Join(dockerCertPath, "ca.pem"),
			CertFile:           filepath.Join(dockerCertPath, "cert.pem"),
			KeyFile:            filepath.Join(dockerCertPath, "key.pem"),
			InsecureSkipVerify: skipTLSVerify,
		}
		tlsConfig, err := tlsconfig.Client(options)
		if err != nil {
			return err
		}

		return client.WithHTTPClient(&http.Client{
			Transport:     &http.Transport{TLSClientConfig: tlsConfig},
			CheckRedirect: client.CheckRedirect,
		})(c)
	}
}

func (d DockerConfig) withHost() client.Opt {
	return func(c *client.Client) error {
		if host := d.Host; host != "" {
			return client.WithHost(host)(c)
		}
		return nil
	}
}

func (d DockerConfig) withVersion() client.Opt {
	return func(c *client.Client) error {
		return client.WithVersion(d.Version)(c)
	}
}