feature: add Bambu Lab firmware version extractor

Extract firmware information from Bambu Lab's firmware download pages
by parsing the __NEXT_DATA__ JSON blob embedded in the page. Supports
all printer models (X1, P1, A1, A1 mini, H2D, H2S, P2S, X1E, H2D Pro).

Provides GetLatestFirmware() and GetAllFirmware() methods that return
version, release date, release notes, download URL, and MD5 checksum.

Closes #45

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

sites/bambulab/bambulab.go

@@ -0,0 +1,167 @@
+package bambulab
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log/slog"
+	"sort"
+	"strings"
+	"time"
+
+	"gitea.stevedudenhoeffer.com/steve/go-extractor"
+)
+
+// FirmwareInfo holds structured firmware information for a Bambu Lab printer.
+type FirmwareInfo struct {
+	Model        string // printer model slug (e.g. "x1", "p1", "a1-mini")
+	Version      string // firmware version (e.g. "01.11.02.00")
+	ReleaseDate  string // release date in YYYY-MM-DD format
+	ReleaseNotes string // English release notes (markdown)
+	DownloadURL  string // direct download URL for the firmware zip
+	MD5          string // MD5 checksum of the firmware file
+}
+
+// Config holds configuration for the Bambu Lab firmware extractor.
+type Config struct{}
+
+// DefaultConfig is the default Bambu Lab configuration.
+var DefaultConfig = Config{}
+
+func (c Config) validate() Config {
+	return c
+}
+
+// firmwarePageURL returns the firmware download page URL for a given printer model.
+func firmwarePageURL(model string) string {
+	return fmt.Sprintf("https://bambulab.com/en/support/firmware-download/%s", model)
+}
+
+// GetLatestFirmware returns the most recent firmware for a given printer model.
+func (c Config) GetLatestFirmware(ctx context.Context, b extractor.Browser, model string) (*FirmwareInfo, error) {
+	c = c.validate()
+
+	all, err := c.GetAllFirmware(ctx, b, model)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(all) == 0 {
+		return nil, fmt.Errorf("no firmware found for model %q", model)
+	}
+
+	return &all[0], nil
+}
+
+// GetLatestFirmware is a convenience function using DefaultConfig.
+func GetLatestFirmware(ctx context.Context, b extractor.Browser, model string) (*FirmwareInfo, error) {
+	return DefaultConfig.GetLatestFirmware(ctx, b, model)
+}
+
+// GetAllFirmware returns all available firmware versions for a given printer model,
+// sorted by release date descending (newest first).
+func (c Config) GetAllFirmware(ctx context.Context, b extractor.Browser, model string) ([]FirmwareInfo, error) {
+	c = c.validate()
+
+	u := firmwarePageURL(model)
+
+	slog.Info("fetching bambulab firmware", "url", u, "model", model)
+	doc, err := b.Open(ctx, u, extractor.OpenPageOptions{})
+	if err != nil {
+		return nil, fmt.Errorf("failed to open bambulab page: %w", err)
+	}
+	defer extractor.DeferClose(doc)
+
+	timeout := 10 * time.Second
+	if err := doc.WaitForNetworkIdle(&timeout); err != nil {
+		slog.Warn("WaitForNetworkIdle failed", "err", err)
+	}
+
+	return extractAllFirmware(doc, model)
+}
+
+// GetAllFirmware is a convenience function using DefaultConfig.
+func GetAllFirmware(ctx context.Context, b extractor.Browser, model string) ([]FirmwareInfo, error) {
+	return DefaultConfig.GetAllFirmware(ctx, b, model)
+}
+
+// nextData represents the top-level __NEXT_DATA__ JSON structure.
+type nextData struct {
+	Props struct {
+		PageProps struct {
+			PrinterMap map[string]printerEntry `json:"printerMap"`
+		} `json:"pageProps"`
+	} `json:"props"`
+}
+
+// printerEntry represents a single printer in the printerMap.
+type printerEntry struct {
+	Key      string           `json:"key"`
+	DevModel string           `json:"devModel"`
+	Name     string           `json:"name"`
+	Versions []firmwareVersion `json:"versions"`
+}
+
+// firmwareVersion represents a single firmware version entry.
+type firmwareVersion struct {
+	Version        string `json:"version"`
+	URL            string `json:"url"`
+	MD5            string `json:"md5"`
+	ReleaseTime    string `json:"release_time"`
+	ReleaseNotesEN string `json:"release_notes_en"`
+}
+
+func extractAllFirmware(doc extractor.Node, model string) ([]FirmwareInfo, error) {
+	scripts := doc.Select("script#__NEXT_DATA__")
+	if len(scripts) == 0 {
+		return nil, fmt.Errorf("no __NEXT_DATA__ script found")
+	}
+
+	txt, err := scripts[0].Text()
+	if err != nil {
+		return nil, fmt.Errorf("failed to read __NEXT_DATA__: %w", err)
+	}
+
+	var data nextData
+	if err := json.Unmarshal([]byte(txt), &data); err != nil {
+		return nil, fmt.Errorf("failed to parse __NEXT_DATA__: %w", err)
+	}
+
+	printer, ok := data.Props.PageProps.PrinterMap[model]
+	if !ok {
+		return nil, fmt.Errorf("model %q not found in printer map", model)
+	}
+
+	var results []FirmwareInfo
+	for _, v := range printer.Versions {
+		info := FirmwareInfo{
+			Model:        model,
+			Version:      v.Version,
+			ReleaseDate:  formatReleaseDate(v.ReleaseTime),
+			ReleaseNotes: strings.TrimSpace(v.ReleaseNotesEN),
+			DownloadURL:  v.URL,
+			MD5:          v.MD5,
+		}
+		results = append(results, info)
+	}
+
+	// Sort by release date descending (newest first)
+	sort.Slice(results, func(i, j int) bool {
+		return results[i].ReleaseDate > results[j].ReleaseDate
+	})
+
+	return results, nil
+}
+
+// formatReleaseDate converts an ISO 8601 timestamp to YYYY-MM-DD.
+func formatReleaseDate(isoTime string) string {
+	t, err := time.Parse(time.RFC3339, isoTime)
+	if err != nil {
+		// Try date-only format
+		t, err = time.Parse("2006-01-02", isoTime)
+		if err != nil {
+			return isoTime
+		}
+	}
+	return t.Format("2006-01-02")
+}