/*
Copyright 2019 The Tekton Authors

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package config

import (
	"fmt"
	"log"
	"os"
	"reflect"
	"strconv"
	"strings"
	"time"

	"github.com/tektoncd/pipeline/pkg/apis/pipeline/pod"
	corev1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/util/sets"
	"sigs.k8s.io/yaml"
)

const (
	// DefaultTimeoutMinutes is used when no timeout is specified.
	DefaultTimeoutMinutes = 60
	// NoTimeoutDuration is used when a pipeline or task should never time out.
	NoTimeoutDuration = 0 * time.Minute
	// DefaultServiceAccountValue is the SA used when one is not specified.
	DefaultServiceAccountValue = "default"
	// DefaultManagedByLabelValue is the value for the managed-by label that is used by default.
	DefaultManagedByLabelValue = "tekton-pipelines"
	// DefaultCloudEventSinkValue is the default value for cloud event sinks.
	DefaultCloudEventSinkValue = ""
	// DefaultMaxMatrixCombinationsCount is used when no max matrix combinations count is specified.
	DefaultMaxMatrixCombinationsCount = 256
	// DefaultResolverTypeValue is used when no default resolver type is specified
	DefaultResolverTypeValue = ""

	defaultTimeoutMinutesKey             = "default-timeout-minutes"
	defaultServiceAccountKey             = "default-service-account"
	defaultManagedByLabelValueKey        = "default-managed-by-label-value"
	defaultPodTemplateKey                = "default-pod-template"
	defaultAAPodTemplateKey              = "default-affinity-assistant-pod-template"
	defaultCloudEventsSinkKey            = "default-cloud-events-sink"
	defaultTaskRunWorkspaceBinding       = "default-task-run-workspace-binding"
	defaultMaxMatrixCombinationsCountKey = "default-max-matrix-combinations-count"
	defaultForbiddenEnv                  = "default-forbidden-env"
	defaultResolverTypeKey               = "default-resolver-type"
)

// Defaults holds the default configurations
// +k8s:deepcopy-gen=true
type Defaults struct {
	DefaultTimeoutMinutes             int
	DefaultServiceAccount             string
	DefaultManagedByLabelValue        string
	DefaultPodTemplate                *pod.Template
	DefaultAAPodTemplate              *pod.AffinityAssistantTemplate
	DefaultCloudEventsSink            string
	DefaultTaskRunWorkspaceBinding    string
	DefaultMaxMatrixCombinationsCount int
	DefaultForbiddenEnv               []string
	DefaultResolverType               string
}

// GetDefaultsConfigName returns the name of the configmap containing all
// defined defaults.
func GetDefaultsConfigName() string {
	if e := os.Getenv("CONFIG_DEFAULTS_NAME"); e != "" {
		return e
	}
	return "config-defaults"
}

// Equals returns true if two Configs are identical
func (cfg *Defaults) Equals(other *Defaults) bool {
	if cfg == nil && other == nil {
		return true
	}

	if cfg == nil || other == nil {
		return false
	}

	return other.DefaultTimeoutMinutes == cfg.DefaultTimeoutMinutes &&
		other.DefaultServiceAccount == cfg.DefaultServiceAccount &&
		other.DefaultManagedByLabelValue == cfg.DefaultManagedByLabelValue &&
		other.DefaultPodTemplate.Equals(cfg.DefaultPodTemplate) &&
		other.DefaultAAPodTemplate.Equals(cfg.DefaultAAPodTemplate) &&
		other.DefaultCloudEventsSink == cfg.DefaultCloudEventsSink &&
		other.DefaultTaskRunWorkspaceBinding == cfg.DefaultTaskRunWorkspaceBinding &&
		other.DefaultMaxMatrixCombinationsCount == cfg.DefaultMaxMatrixCombinationsCount &&
		other.DefaultResolverType == cfg.DefaultResolverType &&
		reflect.DeepEqual(other.DefaultForbiddenEnv, cfg.DefaultForbiddenEnv)
}

// NewDefaultsFromMap returns a Config given a map corresponding to a ConfigMap
func NewDefaultsFromMap(cfgMap map[string]string) (*Defaults, error) {
	tc := Defaults{
		DefaultTimeoutMinutes:             DefaultTimeoutMinutes,
		DefaultServiceAccount:             DefaultServiceAccountValue,
		DefaultManagedByLabelValue:        DefaultManagedByLabelValue,
		DefaultCloudEventsSink:            DefaultCloudEventSinkValue,
		DefaultMaxMatrixCombinationsCount: DefaultMaxMatrixCombinationsCount,
		DefaultResolverType:               DefaultResolverTypeValue,
	}

	if defaultTimeoutMin, ok := cfgMap[defaultTimeoutMinutesKey]; ok {
		timeout, err := strconv.ParseInt(defaultTimeoutMin, 10, 0)
		if err != nil {
			return nil, fmt.Errorf("failed parsing tracing config %q", defaultTimeoutMinutesKey)
		}
		tc.DefaultTimeoutMinutes = int(timeout)
	}

	if defaultServiceAccount, ok := cfgMap[defaultServiceAccountKey]; ok {
		tc.DefaultServiceAccount = defaultServiceAccount
	}

	if defaultManagedByLabelValue, ok := cfgMap[defaultManagedByLabelValueKey]; ok {
		tc.DefaultManagedByLabelValue = defaultManagedByLabelValue
	}

	if defaultPodTemplate, ok := cfgMap[defaultPodTemplateKey]; ok {
		var podTemplate pod.Template
		if err := yamlUnmarshal(defaultPodTemplate, defaultPodTemplateKey, &podTemplate); err != nil {
			return nil, fmt.Errorf("failed to unmarshal %v", defaultPodTemplate)
		}
		tc.DefaultPodTemplate = &podTemplate
	}

	if defaultAAPodTemplate, ok := cfgMap[defaultAAPodTemplateKey]; ok {
		var podTemplate pod.AffinityAssistantTemplate
		if err := yamlUnmarshal(defaultAAPodTemplate, defaultAAPodTemplateKey, &podTemplate); err != nil {
			return nil, fmt.Errorf("failed to unmarshal %v", defaultAAPodTemplate)
		}
		tc.DefaultAAPodTemplate = &podTemplate
	}

	if defaultCloudEventsSink, ok := cfgMap[defaultCloudEventsSinkKey]; ok {
		tc.DefaultCloudEventsSink = defaultCloudEventsSink
	}

	if bindingYAML, ok := cfgMap[defaultTaskRunWorkspaceBinding]; ok {
		tc.DefaultTaskRunWorkspaceBinding = bindingYAML
	}

	if defaultMaxMatrixCombinationsCount, ok := cfgMap[defaultMaxMatrixCombinationsCountKey]; ok {
		matrixCombinationsCount, err := strconv.ParseInt(defaultMaxMatrixCombinationsCount, 10, 0)
		if err != nil {
			return nil, fmt.Errorf("failed parsing tracing config %q", defaultMaxMatrixCombinationsCountKey)
		}
		tc.DefaultMaxMatrixCombinationsCount = int(matrixCombinationsCount)
	}
	if defaultForbiddenEnvString, ok := cfgMap[defaultForbiddenEnv]; ok {
		tmpString := sets.NewString()
		fEnvs := strings.Split(defaultForbiddenEnvString, ",")
		for _, fEnv := range fEnvs {
			tmpString.Insert(strings.TrimSpace(fEnv))
		}
		tc.DefaultForbiddenEnv = tmpString.List()
	}

	if defaultResolverType, ok := cfgMap[defaultResolverTypeKey]; ok {
		tc.DefaultResolverType = defaultResolverType
	}

	return &tc, nil
}

func yamlUnmarshal(s string, key string, o interface{}) error {
	b := []byte(s)
	if err := yaml.UnmarshalStrict(b, o); err != nil {
		log.Printf("warning: failed to decode %q: %q. Trying decode with non-strict mode", key, err)
		return yaml.Unmarshal(b, o)
	}
	return nil
}

// NewDefaultsFromConfigMap returns a Config for the given configmap
func NewDefaultsFromConfigMap(config *corev1.ConfigMap) (*Defaults, error) {
	return NewDefaultsFromMap(config.Data)
}
