// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License. See the LICENSE file in builder/azure for license information.

package arm

import (
	"bytes"
	"fmt"
	"net/url"
	"path"
	"strings"
)

const (
	BuilderId = "Azure.ResourceManagement.VMImage"
)

type Artifact struct {
	StorageAccountLocation string
	OSDiskUri              string
	TemplateUri            string
	OSDiskUriReadOnlySas   string
	TemplateUriReadOnlySas string
}

func NewArtifact(template *CaptureTemplate, getSasUrl func(name string) string) (*Artifact, error) {
	if template == nil {
		return nil, fmt.Errorf("nil capture template")
	}

	if len(template.Resources) != 1 {
		return nil, fmt.Errorf("malformed capture template, expected one resource")
	}

	vhdUri, err := url.Parse(template.Resources[0].Properties.StorageProfile.OSDisk.Image.Uri)
	if err != nil {
		return nil, err
	}

	templateUri, err := storageUriToTemplateUri(vhdUri)
	if err != nil {
		return nil, err
	}

	return &Artifact{
		OSDiskUri:              vhdUri.String(),
		OSDiskUriReadOnlySas:   getSasUrl(getStorageUrlPath(vhdUri)),
		TemplateUri:            templateUri.String(),
		TemplateUriReadOnlySas: getSasUrl(getStorageUrlPath(templateUri)),

		StorageAccountLocation: template.Resources[0].Location,
	}, nil
}

func getStorageUrlPath(u *url.URL) string {
	parts := strings.Split(u.Path, "/")
	return strings.Join(parts[3:], "/")
}

func storageUriToTemplateUri(su *url.URL) (*url.URL, error) {
	// packer-osDisk.4085bb15-3644-4641-b9cd-f575918640b4.vhd -> 4085bb15-3644-4641-b9cd-f575918640b4
	filename := path.Base(su.Path)
	parts := strings.Split(filename, ".")

	if len(parts) < 3 {
		return nil, fmt.Errorf("malformed URL")
	}

	// packer-osDisk.4085bb15-3644-4641-b9cd-f575918640b4.vhd -> packer
	prefixParts := strings.Split(parts[0], "-")
	prefix := strings.Join(prefixParts[:len(prefixParts)-1], "-")

	templateFilename := fmt.Sprintf("%s-vmTemplate.%s.json", prefix, parts[1])

	// https://storage.blob.core.windows.net/system/Microsoft.Compute/Images/images/packer-osDisk.4085bb15-3644-4641-b9cd-f575918640b4.vhd"
	//   ->
	// https://storage.blob.core.windows.net/system/Microsoft.Compute/Images/images/packer-vmTemplate.4085bb15-3644-4641-b9cd-f575918640b4.json"
	return url.Parse(strings.Replace(su.String(), filename, templateFilename, 1))
}

func (*Artifact) BuilderId() string {
	return BuilderId
}

func (*Artifact) Files() []string {
	return []string{}
}

func (*Artifact) Id() string {
	return ""
}

func (*Artifact) State(name string) interface{} {
	return nil
}

func (a *Artifact) String() string {
	var buf bytes.Buffer

	buf.WriteString(fmt.Sprintf("%s:\n\n", a.BuilderId()))
	buf.WriteString(fmt.Sprintf("StorageAccountLocation: %s\n", a.StorageAccountLocation))
	buf.WriteString(fmt.Sprintf("OSDiskUri: %s\n", a.OSDiskUri))
	buf.WriteString(fmt.Sprintf("OSDiskUriReadOnlySas: %s\n", a.OSDiskUriReadOnlySas))
	buf.WriteString(fmt.Sprintf("TemplateUri: %s\n", a.TemplateUri))
	buf.WriteString(fmt.Sprintf("TemplateUriReadOnlySas: %s\n", a.TemplateUriReadOnlySas))

	return buf.String()
}

func (*Artifact) Destroy() error {
	return nil
}