refmt: add env codec

format.go

@@ -13,7 +13,7 @@ import (
 	"strings"
 	"text/template"
 
-	"github.com/rjeczalik/refmt/object"
+	"rafal.dev/refmt/object"
 
 	"github.com/go-sql-driver/mysql"
 	"github.com/hashicorp/hcl"
@@ -27,10 +27,48 @@ var f = &Format{
 	Type: flag.String("t", "", "Output format type."),
 }
 
-var m = map[string]struct {
+type envCodec struct {
+	prefix *string
+}
+
+func (c *envCodec) codec() codec {
+	return codec{
+		marshal:   c.marshal,
+		unmarshal: c.unmarshal,
+	}
+}
+
+func (c *envCodec) marshal(v interface{}) ([]byte, error) {
+	m, ok := v.(map[string]interface{})
+	if !ok {
+		return nil, errors.New("envCoded: cannot marshal non-object value")
+	}
+
+	envs := object.Flatten(m, "_")
+
+	var (
+		p    = *c.prefix
+		keys = object.Keys(envs)
+		buf  bytes.Buffer
+	)
+
+	for _, k := range keys {
+		fmt.Fprintf(&buf, "%s%s=%v\n", p, strings.ToUpper(k), envs[k])
+	}
+
+	return buf.Bytes(), nil
+}
+
+func (c *envCodec) unmarshal([]byte) (interface{}, error) {
+	return nil, errors.New("envCodec: not implemented")
+}
+
+type codec struct {
 	marshal   func(interface{}) ([]byte, error)
 	unmarshal func([]byte) (interface{}, error)
-}{
+}
+
+var m = map[string]codec{
 	"json": {
 		marshal: jsonMarshal,
 		unmarshal: func(p []byte) (v interface{}, _ error) {
@@ -73,6 +111,9 @@ var m = map[string]struct {
 			return v, nil
 		},
 	},
+	"env": (&envCodec{
+		prefix: flag.String("p", "", "Prefix for keys when type is env."),
+	}).codec(),
 }
 
 func typ(file string) string {
@@ -94,7 +135,7 @@ func typ(file string) string {
 	}
 }
 
-var autoTryOrder = []string{"hcl", "json", "yaml"}
+var autoTryOrder = []string{"hcl", "json", "yaml", "env"}
 
 type Format struct {
 	Type   *string   // autodetect if nil or empty

go.mod

@@ -1,15 +1,18 @@
-module github.com/rjeczalik/refmt
+module rafal.dev/refmt
+
+go 1.18
 
 require (
-	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/go-sql-driver/mysql v1.4.0
 	github.com/hashicorp/hcl v0.0.0-20180404174102-ef8a98b0bbce
-	github.com/kr/pretty v0.1.0 // indirect
 	github.com/pkg/errors v0.9.1
 	github.com/savaki/jq v0.0.0-20161209013833-0e6baecebbf8
-	google.golang.org/appengine v1.2.0 // indirect
-	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
 	gopkg.in/yaml.v1 v1.0.0-20140924161607-9f9df34309c0
 )
 
-go 1.13
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/kr/pretty v0.1.0 // indirect
+	google.golang.org/appengine v1.2.0 // indirect
+	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
+)

go.sum

@@ -0,0 +1,24 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-sql-driver/mysql v1.4.0 h1:7LxgVwFb2hIQtMm87NdgAVfXjnt4OePseqT1tKx+opk=
+github.com/go-sql-driver/mysql v1.4.0/go.mod h1:zAC/RDZ24gD3HViQzih4MyKcchzm+sOG5ZlKdlhCg5w=
+github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/hashicorp/hcl v0.0.0-20180404174102-ef8a98b0bbce h1:xdsDDbiBDQTKASoGEZ+pEmF1OnWuu8AQ9I8iNbHNeno=
+github.com/hashicorp/hcl v0.0.0-20180404174102-ef8a98b0bbce/go.mod h1:oZtUIOe8dh44I2q6ScRibXws4Ajl+d+nod3AaR9vL5w=
+github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/savaki/jq v0.0.0-20161209013833-0e6baecebbf8 h1:ajJQhvqPSQFJJ4aV5mDAMx8F7iFi6Dxfo6y62wymLNs=
+github.com/savaki/jq v0.0.0-20161209013833-0e6baecebbf8/go.mod h1:Nw/CCOXNyF5JDd6UpYxBwG5WWZ2FOJ/d5QnXL4KQ6vY=
+golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+google.golang.org/appengine v1.2.0 h1:S0iUepdCWODXRvtE+gcRDd15L+k+k1AiHlMiMjefH24=
+google.golang.org/appengine v1.2.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v1 v1.0.0-20140924161607-9f9df34309c0 h1:POO/ycCATvegFmVuPpQzZFJ+pGZeX22Ufu6fibxDVjU=
+gopkg.in/yaml.v1 v1.0.0-20140924161607-9f9df34309c0/go.mod h1:WDnlLJ4WF5VGsH/HVa3CI79GS0ol3YnhVnKP89i0kNg=

object/merge.go

@@ -2,6 +2,7 @@ package object
 
 import (
 	"fmt"
+	"sort"
 	"strings"
 )
 
@@ -80,6 +81,64 @@ func Merge(in, out map[string]interface{}) error {
 	return nil
 }
 
+func Flatten(in map[string]interface{}, sep string) map[string]interface{} {
+	if len(in) == 0 {
+		return nil
+	}
+
+	root := make(map[string]interface{})
+
+	type elm struct {
+		parent map[string]interface{}
+		key    []string
+		left   []string
+	}
+
+	var (
+		it    elm
+		k     string
+		queue = []elm{{parent: in, left: Keys(in)}}
+	)
+
+	for len(queue) != 0 {
+		it, queue = queue[len(queue)-1], queue[:len(queue)-1]
+		k, it.left = it.left[0], it.left[1:]
+
+		key := clone(it.key, k)
+
+		if len(it.left) != 0 {
+			queue = append(queue, it)
+		}
+
+		switch v := it.parent[k].(type) {
+		case []interface{}:
+			m := make(map[string]interface{}, len(v))
+
+			for i, v := range v {
+				m[fmt.Sprint(i)] = v
+			}
+
+			queue = append(queue, elm{
+				parent: m,
+				key:    key,
+				left:   Keys(m),
+			})
+		case map[string]interface{}:
+			queue = append(queue, elm{
+				parent: v,
+				key:    key,
+				left:   Keys(v),
+			})
+		default:
+			if len(key) != 0 {
+				root[strings.Join(key, sep)] = v
+			}
+		}
+	}
+
+	return root
+}
+
 func SetFlatKeyValue(m map[string]interface{}, key, value string) error {
 	keys := strings.Split(key, ".")
 	it := m
@@ -106,3 +165,28 @@ func SetFlatKeyValue(m map[string]interface{}, key, value string) error {
 
 	return nil
 }
+
+func clone(s []string, vs ...string) []string {
+	sCopy := make([]string, len(s), len(s)+len(vs))
+	copy(sCopy, s)
+
+	for _, v := range vs {
+		if v != "" && v != "-" {
+			sCopy = append(sCopy, v)
+		}
+	}
+
+	return sCopy
+}
+
+func Keys(in map[string]interface{}) []string {
+	keys := make([]string, 0, len(in))
+
+	for k := range in {
+		keys = append(keys, k)
+	}
+
+	sort.Strings(keys)
+
+	return keys
+}