File writing, index sorting

core/index.go

@@ -1,4 +1,12 @@
 package core
+import (
+	"io/ioutil"
+	"os"
+	"sort"
+
+	"github.com/BurntSushi/toml"
+)
+
 // Index is a representation of the index.toml file for referencing all the files in a pack.
 type Index struct {
 	HashFormat string `toml:"hash-format"`
@@ -8,6 +16,8 @@ type Index struct {
 		HashFormat string `toml:"hash-format,omitempty"`
 		Alias      string `toml:"alias,omitempty"`
 	} `toml:"files"`
+	flags     Flags
+	indexFile string
 }
 
 // LoadIndex loads the index file
@@ -17,8 +27,17 @@ func LoadIndex(flags Flags) (Index, error) {
 		return Index{}, err
 	}
 
-	_ = indexFile // TODO finish
-	return Index{}, nil
+	data, err := ioutil.ReadFile(indexFile)
+	if err != nil {
+		return Index{}, err
+	}
+	var index Index
+	if _, err := toml.Decode(string(data), &index); err != nil {
+		return Index{}, err
+	}
+	index.flags = flags
+	index.indexFile = indexFile
+	return index, nil
 }
 
 // RemoveFile removes a file from the index.
@@ -32,3 +51,40 @@ func (in Index) RemoveFile(path string) {
 	in.Files = newFiles
 }
 
+// resortIndex sorts Files by file name
+func (in Index) resortIndex() {
+	sort.SliceStable(in.Files, func(i, j int) bool {
+		// Compare by alias if names are equal?
+		// Remove duplicated entries? (compound key on file/alias?)
+		return in.Files[i].File < in.Files[j].File
+	})
+}
+
+// Refresh updates the hashes of all the files in the index, and adds new files to the index
+func (in Index) Refresh() error {
+	// TODO: implement
+	// process:
+	// enumerate files, exclude index and pack.toml
+	// hash them
+	// check if they exist in list
+	// if exists, modify existing entry(ies)
+	// if not exists, add new entry
+	// resort
+	in.resortIndex()
+	return nil
+}
+
+// Write saves the index file
+func (in Index) Write() error {
+	f, err := os.Create(in.indexFile)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	enc := toml.NewEncoder(f)
+	// Disable indentation
+	enc.Indent = ""
+	return enc.Encode(in)
+}
+