package ecs

import (
	"strconv"
	"strings"
	"text/template"

	"github.com/BurntSushi/ty/fun"
	"github.com/containous/traefik/log"
	"github.com/containous/traefik/provider/label"
	"github.com/containous/traefik/types"
)

// buildConfiguration fills the config template with the given instances
func (p *Provider) buildConfiguration(services map[string][]ecsInstance) (*types.Configuration, error) {
	var ecsFuncMap = template.FuncMap{
		"filterFrontends":         filterFrontends,
		"getFrontendRule":         p.getFrontendRule,
		"getBasicAuth":            getFuncSliceString(label.TraefikFrontendAuthBasic),
		"getLoadBalancerMethod":   getFuncFirstStringValue(label.TraefikBackendLoadBalancerMethod, label.DefaultBackendLoadBalancerMethod),
		"getSticky":               getSticky,
		"hasStickinessLabel":      getFuncFirstBoolValue(label.TraefikBackendLoadBalancerStickiness, false),
		"getStickinessCookieName": getFuncFirstStringValue(label.TraefikBackendLoadBalancerStickinessCookieName, label.DefaultBackendLoadbalancerStickinessCookieName),
		"getProtocol":             getFuncStringValue(label.TraefikProtocol, label.DefaultProtocol),
		"getHost":                 getHost,
		"getPort":                 getPort,
		"getWeight":               getFuncStringValue(label.TraefikWeight, label.DefaultWeight),
		"getPassHostHeader":       getFuncStringValue(label.TraefikFrontendPassHostHeader, label.DefaultPassHostHeader),
		"getPriority":             getFuncStringValue(label.TraefikFrontendPriority, label.DefaultFrontendPriority),
		"getEntryPoints":          getFuncSliceString(label.TraefikFrontendEntryPoints),
		"hasHealthCheckLabels":    hasFuncFirst(label.TraefikBackendHealthCheckPath),
		"getHealthCheckPath":      getFuncFirstStringValue(label.TraefikBackendHealthCheckPath, ""),
		"getHealthCheckInterval":  getFuncFirstStringValue(label.TraefikBackendHealthCheckInterval, ""),
	}
	return p.GetConfiguration("templates/ecs.tmpl", ecsFuncMap, struct {
		Services map[string][]ecsInstance
	}{
		services,
	})
}

func (p *Provider) getFrontendRule(i ecsInstance) string {
	defaultRule := "Host:" + strings.ToLower(strings.Replace(i.Name, "_", "-", -1)) + "." + p.Domain
	return getStringValue(i, label.TraefikFrontendRule, defaultRule)
}

// TODO: Deprecated
// Deprecated replaced by Stickiness
func getSticky(instances []ecsInstance) string {
	if hasFirst(instances, label.TraefikBackendLoadBalancerSticky) {
		log.Warnf("Deprecated configuration found: %s. Please use %s.", label.TraefikBackendLoadBalancerSticky, label.TraefikBackendLoadBalancerStickiness)
	}
	return getFirstStringValue(instances, label.TraefikBackendLoadBalancerSticky, "false")
}

func getHost(i ecsInstance) string {
	return *i.machine.PrivateIpAddress
}

func getPort(i ecsInstance) string {
	if value := getStringValue(i, label.TraefikPort, ""); len(value) > 0 {
		return value
	}
	return strconv.FormatInt(*i.container.NetworkBindings[0].HostPort, 10)
}

func filterFrontends(instances []ecsInstance) []ecsInstance {
	byName := make(map[string]struct{})

	return fun.Filter(func(i ecsInstance) bool {
		_, found := byName[i.Name]
		if !found {
			byName[i.Name] = struct{}{}
		}
		return !found
	}, instances).([]ecsInstance)
}

// Label functions

func getFuncStringValue(labelName string, defaultValue string) func(i ecsInstance) string {
	return func(i ecsInstance) string {
		return getStringValue(i, labelName, defaultValue)
	}
}

func getFuncSliceString(labelName string) func(i ecsInstance) []string {
	return func(i ecsInstance) []string {
		return getSliceString(i, labelName)
	}
}

func hasFuncFirst(labelName string) func(instances []ecsInstance) bool {
	return func(instances []ecsInstance) bool {
		return hasFirst(instances, labelName)
	}
}

func getFuncFirstStringValue(labelName string, defaultValue string) func(instances []ecsInstance) string {
	return func(instances []ecsInstance) string {
		return getFirstStringValue(instances, labelName, defaultValue)
	}
}

func getFuncFirstBoolValue(labelName string, defaultValue bool) func(instances []ecsInstance) bool {
	return func(instances []ecsInstance) bool {
		if len(instances) < 0 {
			return defaultValue
		}
		return getBoolValue(instances[0], labelName, defaultValue)
	}
}

func getStringValue(i ecsInstance, labelName string, defaultValue string) string {
	if v, ok := i.containerDefinition.DockerLabels[labelName]; ok {
		if v == nil {
			return defaultValue
		}
		if len(*v) == 0 {
			return defaultValue
		}
		return *v
	}
	return defaultValue
}

func getBoolValue(i ecsInstance, labelName string, defaultValue bool) bool {
	rawValue, ok := i.containerDefinition.DockerLabels[labelName]
	if ok {
		if rawValue != nil {
			v, err := strconv.ParseBool(*rawValue)
			if err == nil {
				return v
			}
		}
	}
	return defaultValue
}

func getSliceString(i ecsInstance, labelName string) []string {
	if value, ok := i.containerDefinition.DockerLabels[labelName]; ok {
		if value == nil {
			return nil
		}
		if len(*value) == 0 {
			return nil
		}
		return label.SplitAndTrimString(*value, ",")
	}
	return nil
}

func hasFirst(instances []ecsInstance, labelName string) bool {
	if len(instances) > 0 {
		v, ok := instances[0].containerDefinition.DockerLabels[labelName]
		return ok && v != nil && len(*v) != 0
	}
	return false
}

func getFirstStringValue(instances []ecsInstance, labelName string, defaultValue string) string {
	if len(instances) == 0 {
		return defaultValue
	}
	return getStringValue(instances[0], labelName, defaultValue)
}

func isEnabled(i ecsInstance, exposedByDefault bool) bool {
	return getBoolValue(i, label.TraefikEnable, exposedByDefault)
}