package hcl2template

import (
	"fmt"

	"github.com/hashicorp/hcl/v2"
	"github.com/hashicorp/hcl/v2/gohcl"
	"github.com/hashicorp/packer/helper/common"
	"github.com/hashicorp/packer/packer"
)

// ProvisionerBlock references a detected but unparsed provisioner
type ProvisionerBlock struct {
	PType string
	PName string
	HCL2Ref
}

func (p *ProvisionerBlock) String() string {
	return fmt.Sprintf(buildProvisionerLabel+"-block %q %q", p.PType, p.PName)
}

func (p *Parser) decodeProvisioner(block *hcl.Block) (*ProvisionerBlock, hcl.Diagnostics) {
	var b struct {
		Name string   `hcl:"name,optional"`
		Rest hcl.Body `hcl:",remain"`
	}
	diags := gohcl.DecodeBody(block.Body, nil, &b)
	if diags.HasErrors() {
		return nil, diags
	}
	provisioner := &ProvisionerBlock{
		PType:   block.Labels[0],
		PName:   b.Name,
		HCL2Ref: newHCL2Ref(block, b.Rest),
	}

	if !p.ProvisionersSchemas.Has(provisioner.PType) {
		diags = append(diags, &hcl.Diagnostic{
			Summary:  fmt.Sprintf("Unknown "+buildProvisionerLabel+" type %q", provisioner.PType),
			Subject:  block.LabelRanges[0].Ptr(),
			Detail:   fmt.Sprintf("known "+buildProvisionerLabel+"s: %v", p.ProvisionersSchemas.List()),
			Severity: hcl.DiagError,
		})
		return nil, diags
	}
	return provisioner, diags
}

func (p *Parser) startProvisioner(pb *ProvisionerBlock, ectx *hcl.EvalContext, generatedVars []string) (packer.Provisioner, hcl.Diagnostics) {
	var diags hcl.Diagnostics

	provisioner, err := p.ProvisionersSchemas.Start(pb.PType)
	if err != nil {
		diags = append(diags, &hcl.Diagnostic{
			Summary: fmt.Sprintf("failed loading %s", pb.PType),
			Subject: pb.HCL2Ref.LabelsRanges[0].Ptr(),
			Detail:  err.Error(),
		})
		return nil, diags
	}
	flatProvisionerCfg, moreDiags := decodeHCL2Spec(pb.HCL2Ref.Rest, ectx, provisioner)
	diags = append(diags, moreDiags...)
	if diags.HasErrors() {
		return nil, diags
	}
	// manipulate generatedVars from builder to add to the interfaces being
	// passed to the provisioner Prepare()

	// If the builder has provided a list of to-be-generated variables that
	// should be made accessible to provisioners, pass that list into
	// the provisioner prepare() so that the provisioner can appropriately
	// validate user input against what will become available. Otherwise,
	// only pass the default variables, using the basic placeholder data.
	generatedPlaceholderMap := packer.BasicPlaceholderData()
	if generatedVars != nil {
		for _, k := range generatedVars {
			generatedPlaceholderMap[k] = fmt.Sprintf("Generated_%s. "+
				common.PlaceholderMsg, k)
		}
	}
	// configs := make([]interface{}, 2)
	// configs = append(, flatProvisionerCfg)
	// configs = append(configs, generatedPlaceholderMap)
	err = provisioner.Prepare(flatProvisionerCfg, generatedPlaceholderMap)
	if err != nil {
		diags = append(diags, &hcl.Diagnostic{
			Severity: hcl.DiagError,
			Summary:  fmt.Sprintf("Failed preparing %s", pb),
			Detail:   err.Error(),
			Subject:  pb.HCL2Ref.DefRange.Ptr(),
		})
		return nil, diags
	}
	return provisioner, diags
}