formidable/internal/data/format/hcl/decoder_handler.go

166 lines
3.4 KiB
Go

package hcl
import (
"io"
"net/url"
"path"
"path/filepath"
"forge.cadoles.com/wpetit/formidable/internal/data/format"
"github.com/hashicorp/hcl/v2"
"github.com/hashicorp/hcl/v2/gohcl"
"github.com/hashicorp/hcl/v2/hclparse"
"github.com/pkg/errors"
"github.com/zclconf/go-cty/cty"
"github.com/zclconf/go-cty/cty/function"
"github.com/zclconf/go-cty/cty/gocty"
)
const (
ExtensionHCL = ".hcl"
FormatHCL = "hcl"
)
type DecoderHandler struct {
ctx *hcl.EvalContext
}
func (d *DecoderHandler) Match(url *url.URL) bool {
ext := filepath.Ext(path.Join(url.Host, url.Path))
return ext == ExtensionHCL ||
format.MatchURLQueryFormat(url, FormatHCL)
}
func (d *DecoderHandler) Decode(url *url.URL, reader io.Reader) (interface{}, error) {
data, err := io.ReadAll(reader)
if err != nil {
return nil, errors.WithStack(err)
}
ctx := d.ctx
if ctx == nil {
ctx = &hcl.EvalContext{
Variables: make(map[string]cty.Value),
Functions: make(map[string]function.Function),
}
}
parser := hclparse.NewParser()
file, diags := parser.ParseHCL(data, url.String())
if diags.HasErrors() {
return nil, errors.WithStack(diags)
}
var tree map[string]interface{}
diags = gohcl.DecodeBody(file.Body, ctx, &tree)
if diags.HasErrors() {
return nil, errors.WithStack(diags)
}
ctx = ctx.NewChild()
values, err := hclTreeToRawValues(ctx, tree)
if err != nil {
return nil, errors.WithStack(err)
}
return values, nil
}
func NewDecoderHandler(ctx *hcl.EvalContext) *DecoderHandler {
return &DecoderHandler{ctx}
}
func hclTreeToRawValues(ctx *hcl.EvalContext, tree map[string]interface{}) (map[string]interface{}, error) {
values := make(map[string]interface{})
for key, branch := range tree {
v, err := hclBranchToRawValue(ctx, branch)
if err != nil {
return nil, errors.WithStack(err)
}
values[key] = v
}
return values, nil
}
func hclBranchToRawValue(ctx *hcl.EvalContext, branch interface{}) (interface{}, error) {
switch typ := branch.(type) {
case *hcl.Attribute:
val, diags := typ.Expr.Value(ctx)
if diags.HasErrors() {
return nil, errors.WithStack(diags)
}
raw, err := ctyValueToRaw(ctx, val)
if err != nil {
return nil, errors.WithStack(err)
}
return raw, nil
default:
return nil, errors.Errorf("unexpected type '%T'", typ)
}
}
func ctyValueToRaw(ctx *hcl.EvalContext, val cty.Value) (interface{}, error) {
if val.Type().Equals(cty.Bool) {
var raw bool
if err := gocty.FromCtyValue(val, &raw); err != nil {
return nil, errors.WithStack(err)
}
return raw, nil
} else if val.Type().Equals(cty.Number) {
var raw float64
if err := gocty.FromCtyValue(val, &raw); err != nil {
return nil, errors.WithStack(err)
}
return raw, nil
} else if val.Type().Equals(cty.String) {
var raw string
if err := gocty.FromCtyValue(val, &raw); err != nil {
return nil, errors.WithStack(err)
}
return raw, nil
} else if val.Type().IsObjectType() {
obj := make(map[string]interface{})
for k, v := range val.AsValueMap() {
rv, err := ctyValueToRaw(ctx, v)
if err != nil {
return nil, errors.WithStack(err)
}
obj[k] = rv
}
return obj, nil
} else if val.Type().IsTupleType() {
sl := make([]interface{}, 0)
for _, v := range val.AsValueSlice() {
rv, err := ctyValueToRaw(ctx, v)
if err != nil {
return nil, errors.WithStack(err)
}
sl = append(sl, rv)
}
return sl, nil
}
return nil, errors.Errorf("unexpected cty.Type '%s'", val.Type().FriendlyName())
}