Add `notebook` configuration to set default notebook path

docs/config-notebook.md

@@ -0,0 +1,13 @@
+# Notebook configuration
+
+The `[notebook]` section from the [configuration file](config.md) is used to set the default notebook directory.
+If the path starts with _~_ it will be replaced with the user home directory (_$HOME_), this configuration also supports any environment variable.
+```toml
+[notebook]
+dir = "~/notebook" # same as "$HOME/notebook"
+```
+
+ The following properties are customizable:
+
+* `dir` (string)
+    * Path of the default notebook.

docs/config.md

@@ -2,6 +2,7 @@
 
 Each [notebook](notebook.md) contains a configuration file used to customize your experience with `zk`. This file is located at `.zk/config.toml` and uses the [TOML format](https://github.com/toml-lang/toml). It is composed of several optional sections:
 
+* `[notebook]` configures the [default notebook](config-notebook.md)
 * `[note]` sets the [note creation rules](config-note.md)
 * `[extra]` contains free [user variables](config-extra.md) which can be expanded in templates
 * `[group]` defines [note groups](config-group.md) with custom rules
@@ -26,6 +27,10 @@ Notebook configuration files will inherit the settings defined in the global con
 Here's an example of a complete configuration file:
 
 ```toml
+# NOTEBOOK SETTINGS
+[notebook]
+dir = "~/notebook"
+
 # NOTE SETTINGS
 [note]
 

docs/notebook.md

@@ -6,6 +6,8 @@ To create a new notebook, simply run `zk init [<directory>]`.
 
 Most `zk` commands are operating "Git-style" on the notebook containing the current working directory (or one of its parents). However, you can explicitly set which notebook to use with `--notebook-dir` or the `ZK_NOTEBOOK_DIR` environment variable. Setting `ZK_NOTEBOOK_DIR` in your shell configuration (e.g. `~/.profile`) can be used to define a default notebook which `zk` commands will use when the working directory is not in another notebook.
 
+If the [default notebook](config-notebook.md) is set it will be used as `ZK_NOTEBOOK_DIR`, unless this environment variable is not already set.
+
 ## Anatomy of a notebook
 
 Similarly to Git, a notebook is identified by the presence of a `.zk` directory at its root. This directory contains the only `zk`-specific files in your notebook:

internal/cli/container.go

@@ -4,6 +4,7 @@ import (
 	"io"
 	"os"
 	"path/filepath"
+	"strings"
 
 	"github.com/mickael-menu/zk/internal/adapter/editor"
 	"github.com/mickael-menu/zk/internal/adapter/fs"
@@ -71,6 +72,21 @@ func NewContainer(version string) (*Container, error) {
 		}
 	}
 
+	// Set the default notebook if not already set
+	// might be overrided if --notebook-dir flag is present
+	if osutil.GetOptEnv("ZK_NOTEBOOK_DIR").IsNull() && !config.Notebook.Dir.IsNull() {
+		// Expand in case there are environment variables on the path
+		notebookDir := os.Expand(config.Notebook.Dir.Unwrap(), os.Getenv)
+		if strings.HasPrefix(notebookDir, "~") {
+			dirname, err := os.UserHomeDir()
+			if err != nil {
+				return nil, wrap(err)
+			}
+			notebookDir = filepath.Join(dirname, notebookDir[1:])
+		}
+		os.Setenv("ZK_NOTEBOOK_DIR", notebookDir)
+	}
+
 	// Set the default shell if not already set
 	if osutil.GetOptEnv("ZK_SHELL").IsNull() && !config.Tool.Shell.IsEmpty() {
 		os.Setenv("ZK_SHELL", config.Tool.Shell.Unwrap())

internal/core/config.go

@@ -12,19 +12,23 @@ import (
 
 // Config holds the user configuration.
 type Config struct {
-	Note    NoteConfig
-	Groups  map[string]GroupConfig
-	Format  FormatConfig
-	Tool    ToolConfig
-	LSP     LSPConfig
-	Filters map[string]string
-	Aliases map[string]string
-	Extra   map[string]string
+	Notebook NotebookConfig
+	Note     NoteConfig
+	Groups   map[string]GroupConfig
+	Format   FormatConfig
+	Tool     ToolConfig
+	LSP      LSPConfig
+	Filters  map[string]string
+	Aliases  map[string]string
+	Extra    map[string]string
 }
 
 // NewDefaultConfig creates a new Config with the default settings.
 func NewDefaultConfig() Config {
 	return Config{
+		Notebook: NotebookConfig{
+			Dir: opt.NullString,
+		},
 		Note: NoteConfig{
 			FilenameTemplate: "{{id}}",
 			Extension:        "md",
@@ -192,6 +196,11 @@ const (
 	LSPDiagnosticHint    LSPDiagnosticSeverity = 4
 )
 
+// NotebookConfig holds configuration about the default notebook
+type NotebookConfig struct {
+	Dir opt.String
+}
+
 // NoteConfig holds the user configuration used when generating new notes.
 type NoteConfig struct {
 	// Handlebars template used when generating a new filename.
@@ -280,6 +289,12 @@ func ParseConfig(content []byte, path string, parentConfig Config) (Config, erro
 		return config, wrap(err)
 	}
 
+	// Notebook
+	notebook := tomlConf.Notebook
+	if notebook.Dir != "" {
+		config.Notebook.Dir = opt.NewNotEmptyString(notebook.Dir)
+	}
+
 	// Note
 	note := tomlConf.Note
 	if note.Filename != "" {
@@ -472,14 +487,19 @@ func (c GroupConfig) merge(tomlConf tomlGroupConfig, name string) GroupConfig {
 
 // tomlConfig holds the TOML representation of Config
 type tomlConfig struct {
-	Note    tomlNoteConfig
-	Groups  map[string]tomlGroupConfig `toml:"group"`
-	Format  tomlFormatConfig
-	Tool    tomlToolConfig
-	LSP     tomlLSPConfig
-	Extra   map[string]string
-	Filters map[string]string `toml:"filter"`
-	Aliases map[string]string `toml:"alias"`
+	Notebook tomlNotebookConfig
+	Note     tomlNoteConfig
+	Groups   map[string]tomlGroupConfig `toml:"group"`
+	Format   tomlFormatConfig
+	Tool     tomlToolConfig
+	LSP      tomlLSPConfig
+	Extra    map[string]string
+	Filters  map[string]string `toml:"filter"`
+	Aliases  map[string]string `toml:"alias"`
+}
+
+type tomlNotebookConfig struct {
+	Dir string
 }
 
 type tomlNoteConfig struct {

internal/core/config_test.go

@@ -14,6 +14,9 @@ func TestParseDefaultConfig(t *testing.T) {
 
 	assert.Nil(t, err)
 	assert.Equal(t, conf, Config{
+		Notebook: NotebookConfig{
+			Dir: opt.NullString,
+		},
 		Note: NoteConfig{
 			FilenameTemplate: "{{id}}",
 			Extension:        "md",
@@ -66,6 +69,9 @@ func TestParseComplete(t *testing.T) {
 	conf, err := ParseConfig([]byte(`
 		# Comment
 
+		[notebook]
+		dir = "~/notebook"
+
 		[note]
 		filename = "{{id}}.note"
 		extension = "txt"
@@ -142,6 +148,9 @@ func TestParseComplete(t *testing.T) {
 
 	assert.Nil(t, err)
 	assert.Equal(t, conf, Config{
+		Notebook: NotebookConfig{
+			Dir: opt.NewString("~/notebook"),
+		},
 		Note: NoteConfig{
 			FilenameTemplate: "{{id}}.note",
 			Extension:        "txt",