porting - part 4 done

garmin_session.json

@@ -1,5 +1,5 @@
 {
   "domain": "garmin.com",
   "username": "fbleagh",
-  "auth_token": "bearer eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCIsImtpZCI6ImRpLW9hdXRoLXNpZ25lci1wcm9kLTIwMjQtcTEifQ.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.X6aPeccjXy1bjmIuwRKf0V1Owo7EaiUbICO99Ae1JAoKDPHczswttd1Oo64wFg0DhGVstRMv9tx5OOZ4UUgA4Asj3NO8npkC17clIUeQQU7SCLM2FtiDT5FuMyLC7Ad2TA1PndWzCCov3cUouhDXXJkfnsve7On4vgDugV-v4nNzrKv3ro9wpVgZ331fzGs6pJ19eZJSdj6r_g30VD3qEjx3spCu9VBZZdgRRyuTnYqwHlbX2OwM8V6NZ0s-1A_YFgOZu8x7bW-Ndvh6u3v4TGi5LSk4Gjtua1f4eGC0R565ZuqtS84tddLxPoItYxqT69Ixw5DEfTisrBZsAdTXIQ"
+  "auth_token": "bearer eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCIsImtpZCI6ImRpLW9hdXRoLXNpZ25lci1wcm9kLTIwMjQtcTEifQ.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.cdgNSDtkYnySkPdHTHxvck3BZXVZ0H6mGcqU0fJqqRO5cuh0_exgGM_VBLxoos_MqEYeryZqkw__UfwA1dvamoClooPpUFZIcPmsTl_uSILd8IIiWFjhgXJnTybE3mI_hPEaILzWnVDzQX4lv1K_oTzCVx0I7moonRAk3mbccKpj_kWcIm-CFVbuGbApTCJzRoOr46yFPUnbOxeA0eJl8BbPFmPWK0z_FvcLS8q7ZKuksBWW2gorQovqesIG63k-wK1PFOvm2EDosSFW0RTCFY7cBMx3nz_f7jFG9E5qt971z8EcKCq83pWs2CHIqy64KkVoub3CD0LQRKIjilNsEA"
 }

garmin_session.jsonold

@@ -0,0 +1,5 @@
+{
+  "domain": "garmin.com",
+  "username": "fbleagh",
+  "auth_token": "bearer eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCIsImtpZCI6ImRpLW9hdXRoLXNpZ25lci1wcm9kLTIwMjQtcTEifQ.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.aHN1exAr4j-_rjZ06OS9D7o4CpDYR1l09geAK6jh-NmJl4dsy3vWM1sv6c-9yiIO8FmuKhvBA44yKAhFCWOTNIJ3yUG-t8IFbYRMrPxBW4WZ4zqMN8XgVPI9Z_iLR0cEP6AaaAtzpVMWcwHn8wLhDUrpLMeCz7n8jMU0S-caXkByCa4zF1PhVs69hYH89Yn48lA_bFiJtbgx0aINnuu-0JHCj22NRjBTKPGBDcQg2fNapCrHoqZ1y-5BOfyB96u6VFXZZ6JNd-ar1EaVOw4G7zUhQCCDeilqjwQB68yIvbWoOhAyda93yB-_AcBU3wHrGHUaYqULEPSRex8zPxYH7A"
+}

garth/client/auth.go

@@ -0,0 +1,37 @@
+package client
+
+import (
+	"time"
+)
+
+// OAuth1Token represents OAuth 1.0a credentials
+type OAuth1Token struct {
+	Token       string
+	TokenSecret string
+	CreatedAt   time.Time
+}
+
+// Expired checks if token is expired (OAuth1 tokens typically don't expire but we'll implement for consistency)
+func (t *OAuth1Token) Expired() bool {
+	return false // OAuth1 tokens don't typically expire
+}
+
+// OAuth2Token represents OAuth 2.0 credentials
+type OAuth2Token struct {
+	AccessToken  string
+	RefreshToken string
+	TokenType    string
+	ExpiresIn    int
+	ExpiresAt    time.Time
+}
+
+// Expired checks if token is expired
+func (t *OAuth2Token) Expired() bool {
+	return time.Now().After(t.ExpiresAt)
+}
+
+// RefreshIfNeeded refreshes token if expired (implementation pending)
+func (t *OAuth2Token) RefreshIfNeeded(client *Client) error {
+	// Placeholder for token refresh logic
+	return nil
+}

garth/client/client.go

@@ -52,11 +52,16 @@ func NewClient(domain string) (*Client, error) {
 // Login authenticates to Garmin Connect using SSO
 func (c *Client) Login(email, password string) error {
 	ssoClient := sso.NewClient(c.Domain)
-	oauth2Token, err := ssoClient.Login(email, password)
+	oauth2Token, mfaContext, err := ssoClient.Login(email, password)
 	if err != nil {
 		return fmt.Errorf("SSO login failed: %w", err)
 	}
 
+	// Handle MFA required
+	if mfaContext != nil {
+		return fmt.Errorf("MFA required - not implemented yet")
+	}
+
 	c.OAuth2Token = oauth2Token
 	c.AuthToken = fmt.Sprintf("%s %s", oauth2Token.TokenType, oauth2Token.AccessToken)
 

garth/data/base.go

@@ -0,0 +1,142 @@
+package data
+
+import (
+	"errors"
+	"sync"
+	"time"
+
+	"garmin-connect/garth/client"
+)
+
+// Data defines the interface for Garmin Connect data types.
+// Concrete data types (BodyBattery, HRV, Sleep, etc.) must implement this interface.
+//
+// The Get method retrieves data for a single day.
+// The List method concurrently retrieves data for a range of days.
+type Data interface {
+	Get(day time.Time, c *client.Client) (interface{}, error)
+	List(end time.Time, days int, c *client.Client, maxWorkers int) ([]interface{}, error)
+}
+
+// BaseData provides a reusable implementation for data types to embed.
+// It handles the concurrent List() implementation while allowing concrete types
+// to focus on implementing the Get() method for their specific data structure.
+//
+// Usage:
+//
+//	type BodyBatteryData struct {
+//	    data.BaseData
+//	    // ... additional fields
+//	}
+//
+//	func NewBodyBatteryData() *BodyBatteryData {
+//	    bb := &BodyBatteryData{}
+//	    bb.GetFunc = bb.get // Assign the concrete Get implementation
+//	    return bb
+//	}
+//
+//	func (bb *BodyBatteryData) get(day time.Time, c *client.Client) (interface{}, error) {
+//	    // Implementation specific to body battery data
+//	}
+type BaseData struct {
+	// GetFunc must be set by concrete types to implement the Get method.
+	// This function pointer allows BaseData to call the concrete implementation.
+	GetFunc func(day time.Time, c *client.Client) (interface{}, error)
+}
+
+// Get implements the Data interface by calling the configured GetFunc.
+// Returns an error if GetFunc is not set.
+func (b *BaseData) Get(day time.Time, c *client.Client) (interface{}, error) {
+	if b.GetFunc == nil {
+		return nil, errors.New("GetFunc not implemented for this data type")
+	}
+	return b.GetFunc(day, c)
+}
+
+// List implements concurrent data fetching using a worker pool pattern.
+// This method efficiently retrieves data for multiple days by distributing
+// work across a configurable number of workers (goroutines).
+//
+// Parameters:
+//
+//	end: The end date of the range (inclusive)
+//	days: Number of days to fetch (going backwards from end date)
+//	c: Client instance for API access
+//	maxWorkers: Maximum concurrent workers (minimum 1)
+//
+// Returns:
+//
+//	[]interface{}: Slice of results (order matches date range)
+//	error: First error encountered during processing, if any
+func (b *BaseData) List(end time.Time, days int, c *client.Client, maxWorkers int) ([]interface{}, error) {
+	if maxWorkers < 1 {
+		maxWorkers = 1
+	}
+
+	// Generate date range (end backwards for 'days' days)
+	dates := make([]time.Time, days)
+	for i := 0; i < days; i++ {
+		dates[i] = end.AddDate(0, 0, -i)
+	}
+
+	var wg sync.WaitGroup
+	workCh := make(chan time.Time, days)
+	resultsCh := make(chan interface{}, days)
+	errCh := make(chan error, 1)
+	done := make(chan bool)
+
+	// Worker function
+	worker := func() {
+		defer wg.Done()
+		for date := range workCh {
+			result, err := b.Get(date, c)
+			if err != nil {
+				select {
+				case errCh <- err:
+				default:
+				}
+				return
+			}
+			resultsCh <- result
+		}
+	}
+
+	// Start workers
+	wg.Add(maxWorkers)
+	for i := 0; i < maxWorkers; i++ {
+		go worker()
+	}
+
+	// Send work to channel
+	go func() {
+		for _, date := range dates {
+			workCh <- date
+		}
+		close(workCh)
+	}()
+
+	// Close results channel when all workers finish
+	go func() {
+		wg.Wait()
+		close(resultsCh)
+		done <- true
+	}()
+
+	// Collect results
+	var results []interface{}
+	var err error
+
+collect:
+	for {
+		select {
+		case result := <-resultsCh:
+			results = append(results, result)
+		case err = <-errCh:
+			break collect
+		case <-done:
+			break collect
+		}
+	}
+
+	return results, err
+}

garth/data/base_test.go

@@ -0,0 +1,74 @@
+package data
+
+import (
+	"errors"
+	"testing"
+	"time"
+
+	"garmin-connect/garth/client"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// MockData implements Data interface for testing
+type MockData struct {
+	BaseData
+}
+
+// MockClient simulates API client for tests
+type MockClient struct{}
+
+func (mc *MockClient) Get(endpoint string) (interface{}, error) {
+	if endpoint == "error" {
+		return nil, errors.New("mock API error")
+	}
+	return "data for " + endpoint, nil
+}
+
+func TestBaseData_List(t *testing.T) {
+	// Setup mock data type
+	mockData := &MockData{}
+	mockData.GetFunc = func(day time.Time, c *client.Client) (interface{}, error) {
+		return "data for " + day.Format("2006-01-02"), nil
+	}
+
+	// Test parameters
+	end := time.Date(2023, 6, 15, 0, 0, 0, 0, time.UTC)
+	days := 5
+	c := &client.Client{}
+	maxWorkers := 3
+
+	// Execute
+	results, err := mockData.List(end, days, c, maxWorkers)
+
+	// Verify
+	assert.NoError(t, err)
+	assert.Len(t, results, days)
+	assert.Contains(t, results, "data for 2023-06-15")
+	assert.Contains(t, results, "data for 2023-06-11")
+}
+
+func TestBaseData_List_ErrorHandling(t *testing.T) {
+	// Setup mock data type that returns error on specific date
+	mockData := &MockData{}
+	mockData.GetFunc = func(day time.Time, c *client.Client) (interface{}, error) {
+		if day.Day() == 13 {
+			return nil, errors.New("bad luck day")
+		}
+		return "data for " + day.Format("2006-01-02"), nil
+	}
+
+	// Test parameters
+	end := time.Date(2023, 6, 15, 0, 0, 0, 0, time.UTC)
+	days := 5
+	c := &client.Client{}
+	maxWorkers := 2
+
+	// Execute
+	results, err := mockData.List(end, days, c, maxWorkers)
+
+	// Verify
+	assert.Error(t, err)
+	assert.Equal(t, "bad luck day", err.Error())
+	assert.Len(t, results, 4) // Should have some results before error
+}

garth/oauth/oauth.go

@@ -145,8 +145,10 @@ func ExchangeToken(oauth1Token *types.OAuth1Token) (*types.OAuth2Token, error) {
 		return nil, fmt.Errorf("failed to decode OAuth2 token: %w", err)
 	}
 
-	// Set creation time for expiration tracking
-	oauth2Token.CreatedAt = time.Now()
+	// Set expiration time
+	if oauth2Token.ExpiresIn > 0 {
+		oauth2Token.ExpiresAt = time.Now().Add(time.Duration(oauth2Token.ExpiresIn) * time.Second)
+	}
 
 	return &oauth2Token, nil
 }

garth/sso/sso.go

@@ -19,6 +19,13 @@ var (
 	ticketRegex = regexp.MustCompile(`embed\?ticket=([^"]+)"`)
 )
 
+// MFAContext preserves state for resuming MFA login
+type MFAContext struct {
+	SigninURL string
+	CSRFToken string
+	Ticket    string
+}
+
 // Client represents an SSO client
 type Client struct {
 	Domain     string
@@ -34,7 +41,7 @@ func NewClient(domain string) *Client {
 }
 
 // Login performs the SSO authentication flow
-func (c *Client) Login(email, password string) (*types.OAuth2Token, error) {
+func (c *Client) Login(email, password string) (*types.OAuth2Token, *MFAContext, error) {
 	fmt.Printf("Logging in to Garmin Connect (%s) using SSO flow...\n", c.Domain)
 
 	// Step 1: Set up SSO parameters
@@ -62,13 +69,13 @@ func (c *Client) Login(email, password string) (*types.OAuth2Token, error) {
 	embedURL := fmt.Sprintf("https://sso.%s/sso/embed?%s", c.Domain, ssoEmbedParams.Encode())
 	req, err := http.NewRequest("GET", embedURL, nil)
 	if err != nil {
-		return nil, fmt.Errorf("failed to create embed request: %w", err)
+		return nil, nil, fmt.Errorf("failed to create embed request: %w", err)
 	}
 	req.Header.Set("User-Agent", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36")
 
 	resp, err := c.HTTPClient.Do(req)
 	if err != nil {
-		return nil, fmt.Errorf("failed to initialize SSO: %w", err)
+		return nil, nil, fmt.Errorf("failed to initialize SSO: %w", err)
 	}
 	resp.Body.Close()
 
@@ -77,26 +84,26 @@ func (c *Client) Login(email, password string) (*types.OAuth2Token, error) {
 	signinURL := fmt.Sprintf("https://sso.%s/sso/signin?%s", c.Domain, signinParams.Encode())
 	req, err = http.NewRequest("GET", signinURL, nil)
 	if err != nil {
-		return nil, fmt.Errorf("failed to create signin request: %w", err)
+		return nil, nil, fmt.Errorf("failed to create signin request: %w", err)
 	}
 	req.Header.Set("User-Agent", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36")
 	req.Header.Set("Referer", embedURL)
 
 	resp, err = c.HTTPClient.Do(req)
 	if err != nil {
-		return nil, fmt.Errorf("failed to get signin page: %w", err)
+		return nil, nil, fmt.Errorf("failed to get signin page: %w", err)
 	}
 	defer resp.Body.Close()
 
 	body, err := io.ReadAll(resp.Body)
 	if err != nil {
-		return nil, fmt.Errorf("failed to read signin response: %w", err)
+		return nil, nil, fmt.Errorf("failed to read signin response: %w", err)
 	}
 
 	// Extract CSRF token
 	csrfToken := extractCSRFToken(string(body))
 	if csrfToken == "" {
-		return nil, fmt.Errorf("failed to find CSRF token")
+		return nil, nil, fmt.Errorf("failed to find CSRF token")
 	}
 	fmt.Printf("Found CSRF token: %s\n", csrfToken[:10]+"...")
 
@@ -111,7 +118,7 @@ func (c *Client) Login(email, password string) (*types.OAuth2Token, error) {
 
 	req, err = http.NewRequest("POST", signinURL, strings.NewReader(formData.Encode()))
 	if err != nil {
-		return nil, fmt.Errorf("failed to create login request: %w", err)
+		return nil, nil, fmt.Errorf("failed to create login request: %w", err)
 	}
 	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
 	req.Header.Set("User-Agent", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36")
@@ -119,50 +126,110 @@ func (c *Client) Login(email, password string) (*types.OAuth2Token, error) {
 
 	resp, err = c.HTTPClient.Do(req)
 	if err != nil {
-		return nil, fmt.Errorf("failed to submit login: %w", err)
+		return nil, nil, fmt.Errorf("failed to submit login: %w", err)
 	}
 	defer resp.Body.Close()
 
 	body, err = io.ReadAll(resp.Body)
 	if err != nil {
-		return nil, fmt.Errorf("failed to read login response: %w", err)
+		return nil, nil, fmt.Errorf("failed to read login response: %w", err)
 	}
 
 	// Check login result
 	title := extractTitle(string(body))
 	fmt.Printf("Login response title: %s\n", title)
 
+	// Handle MFA requirement
 	if strings.Contains(title, "MFA") {
-		return nil, fmt.Errorf("MFA required - not implemented yet")
+		fmt.Println("MFA required - returning context for ResumeLogin")
+		ticket := extractTicket(string(body))
+		return nil, &MFAContext{
+			SigninURL: signinURL,
+			CSRFToken: csrfToken,
+			Ticket:    ticket,
+		}, nil
 	}
 
 	if title != "Success" {
-		return nil, fmt.Errorf("login failed, unexpected title: %s", title)
+		return nil, nil, fmt.Errorf("login failed, unexpected title: %s", title)
 	}
 
 	// Step 5: Extract ticket for OAuth flow
 	fmt.Println("Extracting OAuth ticket...")
 	ticket := extractTicket(string(body))
 	if ticket == "" {
-		return nil, fmt.Errorf("failed to find OAuth ticket")
+		return nil, nil, fmt.Errorf("failed to find OAuth ticket")
 	}
 	fmt.Printf("Found ticket: %s\n", ticket[:10]+"...")
 
 	// Step 6: Get OAuth1 token
 	oauth1Token, err := oauth.GetOAuth1Token(c.Domain, ticket)
 	if err != nil {
-		return nil, fmt.Errorf("failed to get OAuth1 token: %w", err)
+		return nil, nil, fmt.Errorf("failed to get OAuth1 token: %w", err)
 	}
 	fmt.Println("Got OAuth1 token")
 
 	// Step 7: Exchange for OAuth2 token
 	oauth2Token, err := oauth.ExchangeToken(oauth1Token)
 	if err != nil {
-		return nil, fmt.Errorf("failed to exchange for OAuth2 token: %w", err)
+		return nil, nil, fmt.Errorf("failed to exchange for OAuth2 token: %w", err)
 	}
 	fmt.Printf("Got OAuth2 token: %s\n", oauth2Token.TokenType)
 
-	return oauth2Token, nil
+	return oauth2Token, nil, nil
+}
+
+// ResumeLogin completes authentication after MFA challenge
+func (c *Client) ResumeLogin(mfaCode string, ctx *MFAContext) (*types.OAuth2Token, error) {
+	fmt.Println("Resuming login with MFA code...")
+
+	// Submit MFA form
+	formData := url.Values{
+		"mfa-code": {mfaCode},
+		"embed":    {"true"},
+		"_csrf":    {ctx.CSRFToken},
+	}
+
+	req, err := http.NewRequest("POST", ctx.SigninURL, strings.NewReader(formData.Encode()))
+	if err != nil {
+		return nil, fmt.Errorf("failed to create MFA request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	req.Header.Set("User-Agent", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36")
+	req.Header.Set("Referer", ctx.SigninURL)
+
+	resp, err := c.HTTPClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to submit MFA: %w", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read MFA response: %w", err)
+	}
+
+	// Verify MFA success
+	title := extractTitle(string(body))
+	if title != "Success" {
+		return nil, fmt.Errorf("MFA failed, unexpected title: %s", title)
+	}
+
+	// Continue with ticket flow
+	fmt.Println("Extracting OAuth ticket after MFA...")
+	ticket := extractTicket(string(body))
+	if ticket == "" {
+		return nil, fmt.Errorf("failed to find OAuth ticket after MFA")
+	}
+
+	// Get OAuth1 token
+	oauth1Token, err := oauth.GetOAuth1Token(c.Domain, ticket)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get OAuth1 token: %w", err)
+	}
+
+	// Exchange for OAuth2 token
+	return oauth.ExchangeToken(oauth1Token)
 }
 
 // extractCSRFToken extracts CSRF token from HTML

garth/types/types.go

@@ -72,7 +72,8 @@ type OAuth2Token struct {
 	ExpiresIn    int       `json:"expires_in"`
 	RefreshToken string    `json:"refresh_token"`
 	Scope        string    `json:"scope"`
-	CreatedAt    time.Time // Added for expiration tracking
+	CreatedAt    time.Time // Used for expiration tracking
+	ExpiresAt    time.Time // Computed expiration time
 }
 
 // OAuthConsumer represents OAuth consumer credentials

garth/utils/utils.go

@@ -143,3 +143,12 @@ func Min(a, b int) int {
 	}
 	return b
 }
+
+// DateRange generates a date range from end date backwards for n days
+func DateRange(end time.Time, days int) []time.Time {
+	dates := make([]time.Time, days)
+	for i := 0; i < days; i++ {
+		dates[i] = end.AddDate(0, 0, -i)
+	}
+	return dates
+}

go.mod

@@ -2,6 +2,6 @@ module garmin-connect
 
 go 1.24.2
 
-require (
-	github.com/joho/godotenv v1.5.1
-)
+require github.com/joho/godotenv v1.5.1
+
+require github.com/stretchr/testify v1.11.1 // indirect

go.sum

@@ -1,2 +1,4 @@
 github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
 github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=
+github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=