move providers into providers subdirectory

providers/staticjsonYahooFinance/providerImpl.go

@@ -0,0 +1,92 @@
+package staticjsonYahooFinance
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+)
+
+type security struct {
+	Symbol   string `json:"symbol"`
+	Quantity int    `json:"quantity"`
+}
+
+type account struct {
+	YnabAccountID string     `json:"ynabAccountId"`
+	Securities    []security `json:"securities"`
+}
+
+type inputData struct {
+	Accounts []account `json:"accounts"`
+}
+
+type Provider struct {
+	data   *inputData // Data stored on disk and loaded when program starts
+	client *client    // HTTP client for interacting with Finnhub API
+}
+
+func (p *Provider) Name() string {
+	return "Static JSON - Yahoo Finance"
+}
+
+// Configures the provider for usage via environment variables and inputData
+// If an error is returned, the provider will not be used
+func (p *Provider) Configure() error {
+	var err error
+
+	// Load input data from disk
+	p.data, err = loadInputData()
+	if err != nil {
+		return err
+	}
+
+	p.client, err = newClient()
+	if err != nil {
+		return fmt.Errorf("failed to create new client: %v", err)
+	}
+
+	return nil
+}
+
+// Returns slices of account balances and mapped YNAB account IDs, along with an error
+func (p *Provider) GetBalances() ([]int, []string, error) {
+	balances := make([]int, 0)
+	ynabAccountIDs := make([]string, 0)
+	for i := range p.data.Accounts {
+		balance := 0
+		for j := range p.data.Accounts[i].Securities {
+			price, err := p.client.getChart(p.data.Accounts[i].Securities[j].Symbol)
+			if err != nil {
+				return balances, ynabAccountIDs, fmt.Errorf("failed to get quote for security with symbol '%s': %v", p.data.Accounts[i].Securities[j].Symbol, err)
+			}
+			balance += price * p.data.Accounts[i].Securities[j].Quantity
+		}
+		balances = append(balances, balance)
+		ynabAccountIDs = append(ynabAccountIDs, p.data.Accounts[i].YnabAccountID)
+	}
+	return balances, ynabAccountIDs, nil
+}
+
+// Load input data from disk
+func loadInputData() (*inputData, error) {
+	data := &inputData{}
+
+	f, err := os.Open("data/staticjsonYahooFinance-data.json")
+	if errors.Is(err, os.ErrNotExist) {
+		return nil, fmt.Errorf("this account provider is not configured: missing data/staticjsonYahooFinance-data.json")
+	}
+	defer f.Close()
+	b, err := io.ReadAll(f)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read file data/staticjsonYahooFinance-data.json: %v", err)
+	}
+
+	err = json.Unmarshal(b, data)
+	if err != nil {
+		return nil, fmt.Errorf("failed to unmarshal data/staticjsonYahooFinance-data.json to inputData struct: %v", err)
+	}
+
+	return data, nil
+}