// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: MPL-2.0
package runtimeconfig

import (
	"fmt"
	"regexp"

	"github.com/hashicorp/terraform-provider-google-beta/google-beta/tpgresource"
	transport_tpg "github.com/hashicorp/terraform-provider-google-beta/google-beta/transport"

	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/customdiff"
	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
	runtimeconfig "google.golang.org/api/runtimeconfig/v1beta1"
)

func ResourceRuntimeconfigVariable() *schema.Resource {
	return &schema.Resource{
		Create: resourceRuntimeconfigVariableCreate,
		Read:   resourceRuntimeconfigVariableRead,
		Update: resourceRuntimeconfigVariableUpdate,
		Delete: resourceRuntimeconfigVariableDelete,

		Importer: &schema.ResourceImporter{
			State: resourceRuntimeconfigVariableImport,
		},

		CustomizeDiff: customdiff.All(
			tpgresource.DefaultProviderProject,
		),

		Schema: map[string]*schema.Schema{
			"name": {
				Type:        schema.TypeString,
				Required:    true,
				ForceNew:    true,
				Description: `The name of the variable to manage. Note that variable names can be hierarchical using slashes (e.g. "prod-variables/hostname").`,
			},

			"parent": {
				Type:        schema.TypeString,
				Required:    true,
				ForceNew:    true,
				Description: `The name of the RuntimeConfig resource containing this variable.`,
			},

			"project": {
				Type:        schema.TypeString,
				Optional:    true,
				Computed:    true,
				ForceNew:    true,
				Description: `The ID of the project in which the resource belongs. If it is not provided, the provider project is used.`,
			},

			"value": {
				Type:         schema.TypeString,
				Optional:     true,
				Sensitive:    true,
				ExactlyOneOf: []string{"text", "value"},
			},

			"text": {
				Type:         schema.TypeString,
				Optional:     true,
				Sensitive:    true,
				ExactlyOneOf: []string{"text", "value"},
			},

			"update_time": {
				Type:        schema.TypeString,
				Computed:    true,
				Description: `The timestamp in RFC3339 UTC "Zulu" format, accurate to nanoseconds, representing when the variable was last updated. Example: "2016-10-09T12:33:37.578138407Z".`,
			},
		},
		UseJSONNumber: true,
	}
}

func resourceRuntimeconfigVariableCreate(d *schema.ResourceData, meta interface{}) error {
	config := meta.(*transport_tpg.Config)
	userAgent, err := tpgresource.GenerateUserAgentString(d, config.UserAgent)
	if err != nil {
		return err
	}

	project, err := tpgresource.GetProject(d, config)
	if err != nil {
		return err
	}

	variable, parent, err := newRuntimeconfigVariableFromResourceData(d, project)
	if err != nil {
		return err
	}

	createdVariable, err := config.NewRuntimeconfigClient(userAgent).Projects.Configs.Variables.Create(resourceRuntimeconfigFullName(project, parent), variable).Do()
	if err != nil {
		return err
	}
	d.SetId(createdVariable.Name)

	return setRuntimeConfigVariableToResourceData(d, *createdVariable)
}

func resourceRuntimeconfigVariableRead(d *schema.ResourceData, meta interface{}) error {
	config := meta.(*transport_tpg.Config)
	userAgent, err := tpgresource.GenerateUserAgentString(d, config.UserAgent)
	if err != nil {
		return err
	}

	fullName := d.Id()
	createdVariable, err := config.NewRuntimeconfigClient(userAgent).Projects.Configs.Variables.Get(fullName).Do()
	if err != nil {
		return err
	}

	return setRuntimeConfigVariableToResourceData(d, *createdVariable)
}

func resourceRuntimeconfigVariableUpdate(d *schema.ResourceData, meta interface{}) error {
	config := meta.(*transport_tpg.Config)
	userAgent, err := tpgresource.GenerateUserAgentString(d, config.UserAgent)
	if err != nil {
		return err
	}
	project, err := tpgresource.GetProject(d, config)
	if err != nil {
		return err
	}

	// Update works more like an 'overwrite' method - we build a new runtimeconfig.Variable struct and it becomes the
	// new config. This means our Update logic looks an awful lot like Create (and hence, doesn't use
	// schema.ResourceData.hasChange()).

	variable, _, err := newRuntimeconfigVariableFromResourceData(d, project)
	if err != nil {
		return err
	}

	createdVariable, err := config.NewRuntimeconfigClient(userAgent).Projects.Configs.Variables.Update(variable.Name, variable).Do()
	if err != nil {
		return err
	}

	return setRuntimeConfigVariableToResourceData(d, *createdVariable)
}

func resourceRuntimeconfigVariableDelete(d *schema.ResourceData, meta interface{}) error {
	config := meta.(*transport_tpg.Config)
	userAgent, err := tpgresource.GenerateUserAgentString(d, config.UserAgent)
	if err != nil {
		return err
	}

	fullName := d.Id()

	_, err = config.NewRuntimeconfigClient(userAgent).Projects.Configs.Variables.Delete(fullName).Do()
	if err != nil {
		return err
	}
	d.SetId("")

	return nil
}

func resourceRuntimeconfigVariableImport(d *schema.ResourceData, meta interface{}) ([]*schema.ResourceData, error) {
	config := meta.(*transport_tpg.Config)
	if err := tpgresource.ParseImportId([]string{"projects/(?P<project>[^/]+)/configs/(?P<parent>[^/]+)/variables/(?P<name>[^/]+)", "(?P<parent>[^/]+)/(?P<name>[^/]+)"}, d, config); err != nil {
		return nil, err
	}

	// Replace import id for the resource id
	id, err := tpgresource.ReplaceVars(d, config, "projects/{{project}}/configs/{{parent}}/variables/{{name}}")
	if err != nil {
		return nil, fmt.Errorf("Error constructing id: %s", err)
	}
	d.SetId(id)

	return []*schema.ResourceData{d}, nil
}

// resourceRuntimeconfigVariableFullName turns a given project, runtime config name, and a 'short name' for a runtime
// config variable into a full name (e.g. projects/my-project/configs/my-config/variables/my-variable).
func resourceRuntimeconfigVariableFullName(project, config, name string) string {
	return fmt.Sprintf("projects/%s/configs/%s/variables/%s", project, config, name)
}

// resourceRuntimeconfigVariableParseFullName parses a full name
// (e.g. projects/my-project/configs/my-config/variables/my-variable) by parsing out the
// project, runtime config name, and the short name. Returns "", "", "", err upon error.
func resourceRuntimeconfigVariableParseFullName(fullName string) (project, config, name string, err error) {
	re := regexp.MustCompile("^projects/([^/]+)/configs/([^/]+)/variables/(.+)$")
	matches := re.FindStringSubmatch(fullName)
	if matches == nil {
		return "", "", "", fmt.Errorf("Given full name doesn't match expected regexp; fullname = '%s'", fullName)
	}
	return matches[1], matches[2], matches[3], nil
}

// newRuntimeconfigVariableFromResourceData builds a new runtimeconfig.Variable struct from the data stored in a
// schema.ResourceData. Also returns the full name of the parent. Returns nil, "", err upon error.
func newRuntimeconfigVariableFromResourceData(d *schema.ResourceData, project string) (variable *runtimeconfig.Variable, parent string, err error) {

	text := d.Get("text")
	value := d.Get("value")

	// TODO(selmanj) here we assume it's a simple name, not a full name. Should probably support full name as well
	parent = d.Get("parent").(string)
	name := d.Get("name").(string)

	fullName := resourceRuntimeconfigVariableFullName(project, parent, name)

	variable = &runtimeconfig.Variable{
		Name: fullName,
	}

	if text != "" {
		variable.Text = text.(string)
	} else {
		variable.Value = value.(string)
	}

	return variable, parent, nil
}

// setRuntimeConfigVariableToResourceData stores a provided runtimeconfig.Variable struct inside a schema.ResourceData.
func setRuntimeConfigVariableToResourceData(d *schema.ResourceData, variable runtimeconfig.Variable) error {
	varProject, parent, name, err := resourceRuntimeconfigVariableParseFullName(variable.Name)
	if err != nil {
		return err
	}
	if err := d.Set("name", name); err != nil {
		return fmt.Errorf("Error setting name: %s", err)
	}
	if err := d.Set("parent", parent); err != nil {
		return fmt.Errorf("Error setting parent: %s", err)
	}
	if err := d.Set("project", varProject); err != nil {
		return fmt.Errorf("Error setting project: %s", err)
	}
	if err := d.Set("value", variable.Value); err != nil {
		return fmt.Errorf("Error setting value: %s", err)
	}
	if err := d.Set("text", variable.Text); err != nil {
		return fmt.Errorf("Error setting text: %s", err)
	}
	if err := d.Set("update_time", variable.UpdateTime); err != nil {
		return fmt.Errorf("Error setting update_time: %s", err)
	}

	return nil
}