Add Yahoo Finance module (#1066)

* Move finnhub to a stocks folder

As I am preparing an other stocks data provider, let's move `finnhub` to
a stocks folder that will host the others providers.

* Use go-pretty v6

Will be used by the new stock provider module, so let's just upgrade
this one to reduce the number of dependencies.

* Add Yahoo Finance module

Yahoo Finance provides an API for which `piquette/finance-go` is a
powerful client. This new module leverages this module to integrate all
indices provided by Yahoo Finance (international stocks, crypto,
options, currencies...)

Sample config:
```yaml
    yfinance:
      title: "Stocks 🚀"
      symbols:
        - "MSFT"
        - "GC=F"
        - "ORA.PA"
      sort: true
      enabled: true
      refreshInterval: 60
      position:
        top: 1
        left: 0
        height: 1
        width: 1
```

modules/stocks/finnhub/client.go

@@ -0,0 +1,80 @@
+package finnhub
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+)
+
+// Client ..
+type Client struct {
+	symbols []string
+	apiKey  string
+}
+
+// NewClient ..
+func NewClient(symbols []string, apiKey string) *Client {
+	client := Client{
+		symbols: symbols,
+		apiKey:  apiKey,
+	}
+
+	return &client
+}
+
+// Getquote ..
+func (client *Client) Getquote() ([]Quote, error) {
+	quotes := []Quote{}
+
+	for _, s := range client.symbols {
+		resp, err := client.finnhubRequest(s)
+		if err != nil {
+			return quotes, err
+		}
+
+		var quote Quote
+		quote.Stock = s
+		err = json.NewDecoder(resp.Body).Decode(&quote)
+		if err != nil {
+			return quotes, err
+		}
+		quotes = append(quotes, quote)
+	}
+
+	return quotes, nil
+}
+
+/* -------------------- Unexported Functions -------------------- */
+
+var (
+	finnhubURL = &url.URL{Scheme: "https", Host: "finnhub.io", Path: "/api/v1/quote"}
+)
+
+func (client *Client) finnhubRequest(symbol string) (*http.Response, error) {
+	params := url.Values{}
+	params.Add("symbol", symbol)
+	params.Add("token", client.apiKey)
+
+	url := finnhubURL.ResolveReference(&url.URL{RawQuery: params.Encode()})
+
+	req, err := http.NewRequest("GET", url.String(), nil)
+	req.Header.Add("Accept", "application/json")
+	req.Header.Add("Content-Type", "application/json")
+	if err != nil {
+		return nil, err
+	}
+
+	httpClient := &http.Client{}
+	resp, err := httpClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode < 200 || resp.StatusCode > 299 {
+		return nil, fmt.Errorf(resp.Status)
+	}
+
+	return resp, nil
+}

modules/stocks/finnhub/quote.go

@@ -0,0 +1,12 @@
+package finnhub
+
+type Quote struct {
+	C  float64 `json:"c"`
+	H  float64 `json:"h"`
+	L  float64 `json:"l"`
+	O  float64 `json:"o"`
+	Pc float64 `json:"pc"`
+	T  int     `json:"t"`
+
+	Stock string
+}

modules/stocks/finnhub/settings.go

@@ -0,0 +1,37 @@
+package finnhub
+
+import (
+	"os"
+
+	"github.com/olebedev/config"
+	"github.com/wtfutil/wtf/cfg"
+	"github.com/wtfutil/wtf/utils"
+)
+
+const (
+	defaultFocusable = true
+	defaultTitle     = "📈 Stocks Price"
+)
+
+// Settings defines the configuration properties for this module
+type Settings struct {
+	*cfg.Common
+
+	apiKey  string   `help:"Your finnhub API token."`
+	symbols []string `help:"An array of stocks symbols (i.e. AAPL, MSFT)"`
+}
+
+// NewSettingsFromYAML creates a new settings instance from a YAML config block
+func NewSettingsFromYAML(name string, ymlConfig *config.Config, globalConfig *config.Config) *Settings {
+
+	settings := Settings{
+		Common: cfg.NewCommonSettingsFromModule(name, defaultTitle, defaultFocusable, ymlConfig, globalConfig),
+
+		apiKey:  ymlConfig.UString("apiKey", ymlConfig.UString("apikey", os.Getenv("WTF_FINNHUB_API_KEY"))),
+		symbols: utils.ToStrs(ymlConfig.UList("symbols")),
+	}
+
+	cfg.ModuleSecret(name, globalConfig, &settings.apiKey).Load()
+
+	return &settings
+}

modules/stocks/finnhub/widget.go

@@ -0,0 +1,61 @@
+package finnhub
+
+import (
+	"fmt"
+
+	"github.com/jedib0t/go-pretty/v6/table"
+	"github.com/rivo/tview"
+	"github.com/wtfutil/wtf/view"
+)
+
+// Widget ..
+type Widget struct {
+	view.TextWidget
+	*Client
+
+	settings *Settings
+}
+
+// NewWidget ..
+func NewWidget(tviewApp *tview.Application, settings *Settings) *Widget {
+	widget := Widget{
+		Client:     NewClient(settings.symbols, settings.apiKey),
+		TextWidget: view.NewTextWidget(tviewApp, nil, settings.Common),
+
+		settings: settings,
+	}
+
+	return &widget
+}
+
+/* -------------------- Exported Functions -------------------- */
+
+func (widget *Widget) Refresh() {
+	if widget.Disabled() {
+		return
+	}
+
+	widget.Redraw(widget.content)
+}
+
+/* -------------------- Unexported Functions -------------------- */
+
+func (widget *Widget) content() (string, string, bool) {
+	quotes, err := widget.Client.Getquote()
+
+	title := widget.CommonSettings().Title
+	t := table.NewWriter()
+	t.AppendHeader(table.Row{"#", "Stock", "Current Price", "Open Price", "Change"})
+	wrap := false
+	if err != nil {
+		wrap = true
+	} else {
+		for idx, q := range quotes {
+			t.AppendRows([]table.Row{
+				{idx, q.Stock, q.C, q.O, fmt.Sprintf("%.4f", (q.C-q.O)/q.C)},
+			})
+		}
+	}
+
+	return title, t.Render(), wrap
+}