package handlers

import (
	"git.ztn.sh/gwendolyn/docker-event-handler/events"

	"bytes"
	"errors"
	"fmt"
	"os/exec"
	"text/template"

	"github.com/google/shlex"
	"github.com/ryanuber/go-glob"
	"gopkg.in/ini.v1"
)

func ReadFromConfig(section *ini.Section) (Handler, error) {
	switch section.Name() {
	case "Container":
		return readContainerFromConfig(section)
	case "Network":
		return readNetworkFromConfig(section)
	case "Volume":
		return readVolumeFromConfig(section)
	default:
		return nil, errors.New(fmt.Sprintf("unknown section %v", section.Name()))
	}
}

type Handler interface {
	Matches(event events.Event) bool
	Invoke(event events.Event) error
}

func stringListMatches(list []string, subject string) bool {
	if len(list) == 0 {
		return true
	}
	for _, pattern := range list {
		if glob.Glob(pattern, subject) {
			return true
		}
	}
	return false
}

func labelsMatch(want map[string]*string, has map[string]string) bool {
	for key, val := range want {
		actualVal, exists := has[key]
		if !exists {
			return false
		}
		if val != nil {
			if actualVal != *val {
				return false
			}
		}
	}
	return true
}

func runTemplatedScript(template *template.Template, data interface{}) error {
	var cmdBuf bytes.Buffer
	err := template.Execute(&cmdBuf, data)
	if err != nil {
		return err
	}
	parts, err := shlex.Split(cmdBuf.String())
	if err != nil {
		return err
	}

	if len(parts) < 1 {
		return errors.New("no handler given")
	}
	name := parts[0]
	args := parts[1:]

	return exec.Command(name, args...).Run()
}