add marketman arbitrage engine provider

providers/marketman/marketman.go

@@ -0,0 +1,89 @@
+package marketman
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"math"
+	"net/http"
+	"os"
+	"path/filepath"
+	"time"
+)
+
+const cacheFilePath = "data/marketman.json"
+const cacheDuration = 6 * time.Hour
+
+type walletData struct {
+	Current struct {
+		TotalValueCad float64 `json:"total_value_cad"`
+	} `json:"current"`
+}
+
+type Provider struct {
+	serverURL   string
+	ynabAccount string
+}
+
+func (p *Provider) Name() string {
+	return "marketman"
+}
+
+func (p *Provider) Configure() error {
+	p.serverURL = os.Getenv("marketman_server")
+	if p.serverURL == "" {
+		return fmt.Errorf("marketman_server environment variable is not set")
+	}
+
+	p.ynabAccount = os.Getenv("marketman_ynab_account")
+	if p.ynabAccount == "" {
+		return fmt.Errorf("marketman_ynab_account environment variable is not set")
+	}
+
+	return nil
+}
+
+func (p *Provider) GetBalances() ([]int, []string, error) {
+	var data walletData
+
+	// Check if cache file exists and is recent enough
+	if stat, err := os.Stat(cacheFilePath); err == nil {
+		if time.Since(stat.ModTime()) < cacheDuration {
+			fileData, err := os.ReadFile(cacheFilePath)
+			if err == nil {
+				if err := json.Unmarshal(fileData, &data); err == nil {
+					cents := int(math.Round(data.Current.TotalValueCad * 100))
+					return []int{cents}, []string{p.ynabAccount}, nil
+				}
+			}
+		}
+	}
+
+	// Fetch fresh data
+	resp, err := http.Get(fmt.Sprintf("%s/api/wallet/data", p.serverURL))
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to fetch wallet data: %v", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, nil, fmt.Errorf("unexpected status code: %d", resp.StatusCode)
+	}
+
+	bodyBytes, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to read response body: %v", err)
+	}
+
+	if err := json.Unmarshal(bodyBytes, &data); err != nil {
+		return nil, nil, fmt.Errorf("failed to decode wallet data: %v", err)
+	}
+
+	// Save raw response to cache file
+	os.MkdirAll(filepath.Dir(cacheFilePath), 0755)
+	_ = os.WriteFile(cacheFilePath, bodyBytes, 0644)
+
+	cents := int(math.Round(data.Current.TotalValueCad * 100))
+
+	return []int{cents}, []string{p.ynabAccount}, nil
+}