/*
Copyright 2021 The KubeVela 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 plugins

import (
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"strconv"
	"strings"

	"cuelang.org/go/cue"
	"github.com/olekukonko/tablewriter"

	"github.com/oam-dev/kubevela/apis/types"
	mycue "github.com/oam-dev/kubevela/pkg/cue"
	"github.com/oam-dev/kubevela/pkg/utils/common"
)

const (
	// BaseRefPath is the target path for reference docs
	BaseRefPath = "docs/en/developers/references"
	// ReferenceSourcePath is the location for source reference
	ReferenceSourcePath = "hack/references"

	// ComponentDefinitionTypePath is the URL path for component typed capability
	ComponentDefinitionTypePath = "component-types"
	// WorkloadTypePath is the URL path for workload typed capability
	WorkloadTypePath = "workload-types"
	// TraitPath is the URL path for trait typed capability
	TraitPath = "traits"
)

// Int64Type is int64 type
type Int64Type = int64

// StringType is string type
type StringType = string

// BoolType is bool type
type BoolType = bool

// Reference is the struct for capability information
type Reference interface {
	prepareParameter(tableName string, parameterList []ReferenceParameter) string
}

// ParseReference is used to include the common function `parseParameter`
type ParseReference struct {
}

// MarkdownReference is the struct for capability information in
type MarkdownReference struct {
	ParseReference
}

// ConsoleReference is the struct for capability information in console
type ConsoleReference struct {
	ParseReference
	TableName   string             `json:"tableName"`
	TableObject *tablewriter.Table `json:"tableObject"`
}

// ConfigurationYamlSample stores the configuration yaml sample for capabilities
var ConfigurationYamlSample = map[string]string{
	"autoscale": `
name: testapp

services:
  express-server:
    ...

    autoscale:
      min: 1
      max: 4
      cron:
        startAt:  "14:00"
        duration: "2h"
        days:     "Monday, Thursday"
        replicas: 2
        timezone: "America/Los_Angeles"
      cpuPercent: 10
`,
	"metrics": `
name: my-app-name

services:
  my-service-name:
    ...
    metrics:
      format: "prometheus"
      port: 8080
      path: "/metrics"
      scheme:  "http"
      enabled: true
`,
	"rollout": `
servcies:
  express-server:
    ...

    rollout:
      replicas: 2
      stepWeight: 50
      interval: "10s"
`,
	"route": `
name: my-app-name

services:
  my-service-name:
    ...
    route:
      domain: example.com
      issuer: tls
      rules:
        - path: /testapp
          rewriteTarget: /
`,
	"scaler": `
name: my-app-name

services:
  my-service-name:
    ...
    scaler:
      replicas: 100
`,
	"task": `
name: my-app-name

services:
  my-service-name:
    type: task
    image: perl
    count: 10
    cmd: ["perl",  "-Mbignum=bpi", "-wle", "print bpi(2000)"]
`,
	"webservice": `
name: my-app-name

services:
  my-service-name:
    type: webservice # could be skipped
    image: oamdev/testapp:v1
    cmd: ["node", "server.js"]
    port: 8080
    cpu: "0.1"
    env:
      - name: FOO
        value: bar
      - name: FOO
        valueFrom:
          secretKeyRef:
            name: bar
            key: bar
`,
	"worker": `
name: my-app-name

services:
  my-service-name:
    type: worker
    image: oamdev/testapp:v1
    cmd: ["node", "server.js"]
`,
}

// ReferenceParameter is the parameter section of CUE template
type ReferenceParameter struct {
	types.Parameter `json:",inline,omitempty"`
	// PrintableType is same to `parameter.Type` which could be printable
	PrintableType string `json:"printableType"`
	// Depth marks the depth for calling of function `parseParameters`
	Depth *int `json:"depth"`
}

var refContent string
var recurseDepth *int
var propertyConsole []ConsoleReference
var displayFormat *string

func setDisplayFormat(format string) {
	displayFormat = &format
}

// GenerateReferenceDocs generates reference docs
func (ref *MarkdownReference) GenerateReferenceDocs(baseRefPath string) error {
	c, err := common.InitBaseRestConfig()
	if err != nil {
		return err
	}
	caps, err := LoadAllInstalledCapability("default", c)
	if err != nil {
		return fmt.Errorf("failed to generate reference docs for all capabilities: %w", err)
	}
	if baseRefPath == "" {
		baseRefPath = BaseRefPath
	}
	return ref.CreateMarkdown(caps, baseRefPath, ReferenceSourcePath)
}

// CreateMarkdown creates markdown based on capabilities
func (ref *MarkdownReference) CreateMarkdown(caps []types.Capability, baseRefPath, referenceSourcePath string) error {
	setDisplayFormat("markdown")
	var capabilityType string
	var specificationType string
	for _, c := range caps {
		switch c.Type {
		case types.TypeWorkload:
			capabilityType = WorkloadTypePath
			specificationType = "workload type"
		case types.TypeComponentDefinition:
			capabilityType = ComponentDefinitionTypePath
			specificationType = "component type"
		case types.TypeTrait:
			capabilityType = TraitPath
			specificationType = "trait"

		default:
			return fmt.Errorf("the type of the capability is not right")
		}

		fileName := fmt.Sprintf("%s.md", c.Name)
		filePath := filepath.Join(baseRefPath, capabilityType)
		if _, err := os.Stat(filePath); err != nil && os.IsNotExist(err) {
			if err := os.MkdirAll(filePath, 0750); err != nil {
				return err
			}
		}

		markdownFile := filepath.Join(baseRefPath, capabilityType, fileName)
		f, err := os.OpenFile(filepath.Clean(markdownFile), os.O_WRONLY|os.O_CREATE, 0600)
		if err != nil {
			return fmt.Errorf("failed to open file %s: %w", markdownFile, err)
		}
		if err = os.Truncate(markdownFile, 0); err != nil {
			return fmt.Errorf("failed to truncate file %s: %w", markdownFile, err)
		}
		capName := c.Name

		cueValue, err := common.GetCUEParameterValue(c.CueTemplate)
		if err != nil {
			return fmt.Errorf("failed to retrieve `parameters` value from %s with err: %w", c.Name, err)
		}
		refContent = ""
		var defaultDepth = 0
		recurseDepth = &defaultDepth
		capNameInTitle := strings.Title(capName)
		if err := ref.parseParameters(cueValue, "Properties", defaultDepth); err != nil {
			return err
		}
		title := fmt.Sprintf("# %s", capNameInTitle)
		description := fmt.Sprintf("\n\n## Description\n\n%s", c.Description)
		specificationIntro := fmt.Sprintf("List of all configuration options for a `%s` %s.", capNameInTitle, specificationType)
		specificationContent := ref.generateSpecification(capName)
		if err != nil {
			return err
		}
		specification := fmt.Sprintf("\n\n## Specification\n\n%s\n\n%s", specificationIntro, specificationContent)

		// it's fine if the conflict info files not found
		conflictWithAndMoreSection, _ := ref.generateConflictWithAndMore(capName, referenceSourcePath)

		refContent = title + description + specification + refContent + conflictWithAndMoreSection
		if _, err := f.WriteString(refContent); err != nil {
			return err
		}
		if err := f.Close(); err != nil {
			return err
		}
	}
	return nil
}

// prepareParameter prepares the table content for each property
func (ref *MarkdownReference) prepareParameter(tableName string, parameterList []ReferenceParameter) string {
	refContent := fmt.Sprintf("\n\n%s\n\n", tableName)
	refContent += "Name | Description | Type | Required | Default \n"
	refContent += "------------ | ------------- | ------------- | ------------- | ------------- \n"
	for _, p := range parameterList {
		printableDefaultValue := ref.getPrintableDefaultValue(p.Default)
		refContent += fmt.Sprintf(" %s | %s | %s | %t | %s \n", p.Name, p.Usage, p.PrintableType, p.Required, printableDefaultValue)
	}
	return refContent
}

// prepareParameter prepares the table content for each property
func (ref *ConsoleReference) prepareParameter(tableName string, parameterList []ReferenceParameter) ConsoleReference {
	table := tablewriter.NewWriter(os.Stdout)
	table.SetColWidth(100)
	table.SetHeader([]string{"Name", "Description", "Type", "Required", "Default"})
	for _, p := range parameterList {
		printableDefaultValue := ref.getPrintableDefaultValue(p.Default)
		table.Append([]string{p.Name, p.Usage, p.PrintableType, strconv.FormatBool(p.Required), printableDefaultValue})
	}
	return ConsoleReference{TableName: tableName, TableObject: table}
}

// parseParameters parses every parameter
func (ref *ParseReference) parseParameters(paraValue cue.Value, paramKey string, depth int) error {
	var params []ReferenceParameter
	*recurseDepth++
	switch paraValue.Kind() {
	case cue.StructKind:
		arguments, err := paraValue.Struct()
		if err != nil {
			return fmt.Errorf("arguments not defined as struct %w", err)
		}
		for i := 0; i < arguments.Len(); i++ {
			var param ReferenceParameter
			fi := arguments.Field(i)
			if fi.IsDefinition {
				continue
			}
			val := fi.Value
			name := fi.Name
			param.Name = name
			param.Required = !fi.IsOptional
			if def, ok := val.Default(); ok && def.IsConcrete() {
				param.Default = mycue.GetDefault(def)
			}
			param.Short, param.Usage, param.Alias = mycue.RetrieveComments(val)
			param.Type = val.IncompleteKind()
			switch val.IncompleteKind() {
			case cue.StructKind:
				depth := *recurseDepth
				if subField, _ := val.Struct(); subField.Len() == 0 { // err cannot be not nil,so ignore it
					if mapValue, ok := val.Elem(); ok {
						// In the future we could recursive call to surpport complex map-value(struct or list)
						param.PrintableType = fmt.Sprintf("map[string]%s", mapValue.IncompleteKind().String())
					} else {
						return fmt.Errorf("failed to got Map kind from %s", param.Name)
					}
				} else {
					if err := ref.parseParameters(val, name, depth); err != nil {
						return err
					}
					param.PrintableType = fmt.Sprintf("[%s](#%s)", name, name)
				}
			case cue.ListKind:
				elem, success := val.Elem()
				if !success {
					return fmt.Errorf("failed to get elements from %s", val)
				}
				switch elem.Kind() {
				case cue.StructKind:
					param.PrintableType = fmt.Sprintf("[[]%s](#%s)", name, name)
					depth := *recurseDepth
					if err := ref.parseParameters(elem, name, depth); err != nil {
						return err
					}
				default:
					param.Type = elem.Kind()
					param.PrintableType = fmt.Sprintf("[]%s", elem.IncompleteKind().String())
				}
			default:
				param.PrintableType = param.Type.String()
			}
			params = append(params, param)
		}
	default:
		//
	}

	switch *displayFormat {
	case "markdown":
		tableName := fmt.Sprintf("%s %s", strings.Repeat("#", depth+2), paramKey)
		ref := MarkdownReference{}
		refContent = ref.prepareParameter(tableName, params) + refContent
	case "console":
		ref := ConsoleReference{}
		tableName := fmt.Sprintf("%s %s", strings.Repeat("#", depth+1), paramKey)
		console := ref.prepareParameter(tableName, params)
		propertyConsole = append([]ConsoleReference{console}, propertyConsole...)
	}
	return nil
}

// getPrintableDefaultValue converts the value in `interface{}` type to be printable
func (ref *ParseReference) getPrintableDefaultValue(v interface{}) string {
	if v == nil {
		return ""
	}
	switch value := v.(type) {
	case Int64Type:
		return strconv.FormatInt(value, 10)
	case StringType:
		if v == "" {
			return "empty"
		}
		return value
	case BoolType:
		return strconv.FormatBool(value)
	}
	return ""
}

// generateSpecification generates Specification part for reference docs
func (ref *MarkdownReference) generateSpecification(capabilityName string) string {
	return fmt.Sprintf("```yaml%s```", ConfigurationYamlSample[capabilityName])
}

// generateConflictWithAndMore generates Section `Conflicts With` and more like `How xxx works` in reference docs
func (ref *MarkdownReference) generateConflictWithAndMore(capabilityName string, referenceSourcePath string) (string, error) {
	conflictWithFile, err := filepath.Abs(filepath.Join(referenceSourcePath, "conflictsWithAndMore", fmt.Sprintf("%s.md", capabilityName)))
	if err != nil {
		return "", fmt.Errorf("failed to locate conflictWith file: %w", err)
	}
	data, err := ioutil.ReadFile(filepath.Clean(conflictWithFile))
	if err != nil {
		return "", err
	}
	return "\n" + string(data), nil
}

// GenerateCapabilityProperties get all properties of a capability
func (ref *ConsoleReference) GenerateCapabilityProperties(capability *types.Capability) ([]ConsoleReference, error) {
	setDisplayFormat("console")
	capName := capability.Name

	cueValue, err := common.GetCUEParameterValue(capability.CueTemplate)
	if err != nil {
		return nil, fmt.Errorf("failed to retrieve `parameters` value from %s with err: %w", capName, err)
	}
	var defaultDepth = 0
	recurseDepth = &defaultDepth
	if err := ref.parseParameters(cueValue, "Properties", defaultDepth); err != nil {
		return nil, err
	}

	return propertyConsole, nil
}