refactor: js plugin api

parsers/js/js.go

@@ -0,0 +1,172 @@
+package js
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sync"
+
+	"github.com/charmbracelet/log"
+	"github.com/dop251/goja"
+	"github.com/krau/SaveAny-Bot/config"
+	"github.com/krau/SaveAny-Bot/pkg/parser"
+)
+
+type jsParser struct {
+	meta  PluginMeta
+	vm    *goja.Runtime
+	reqCh chan jsParserReq
+}
+
+type jsParserReq struct {
+	method ParserMethod
+	url    string
+	respCh chan jsParserResp
+}
+
+type jsParserResp struct {
+	item *parser.Item
+	ok   bool
+	err  error
+}
+
+func (p *jsParser) CanHandle(url string) bool {
+	respCh := make(chan jsParserResp, 1)
+	p.reqCh <- jsParserReq{method: ParserMethodCanHandle, url: url, respCh: respCh}
+	resp := <-respCh
+	return resp.ok && resp.err == nil
+}
+
+func (p *jsParser) Parse(ctx context.Context, url string) (*parser.Item, error) {
+	respCh := make(chan jsParserResp, 1)
+	p.reqCh <- jsParserReq{method: ParserMethodParse, url: url, respCh: respCh}
+	select {
+	case resp := <-respCh:
+		return resp.item, resp.err
+	case <-ctx.Done():
+		return nil, ctx.Err()
+	}
+}
+
+func newJSParser(vm *goja.Runtime, canHandleFunc, parseFunc goja.Value, metadata PluginMeta) *jsParser {
+	p := &jsParser{
+		vm:    vm,
+		reqCh: make(chan jsParserReq, 10),
+		meta:  metadata,
+	}
+
+	go func() {
+		for req := range p.reqCh {
+			switch req.method {
+			case ParserMethodCanHandle:
+				fn, _ := goja.AssertFunction(canHandleFunc)
+				res, err := fn(goja.Undefined(), p.vm.ToValue(req.url))
+				if err != nil {
+					req.respCh <- jsParserResp{ok: false, err: err}
+					continue
+				}
+				req.respCh <- jsParserResp{ok: res.ToBoolean()}
+			case ParserMethodParse:
+				fn, _ := goja.AssertFunction(parseFunc)
+				result, err := fn(goja.Undefined(), p.vm.ToValue(req.url))
+				if err != nil {
+					req.respCh <- jsParserResp{err: err}
+					continue
+				}
+
+				var item parser.Item
+				if exported := result.Export(); exported != nil {
+					data, err := json.Marshal(exported)
+					if err != nil {
+						req.respCh <- jsParserResp{err: fmt.Errorf("failed to marshal result to JSON: %w", err)}
+						continue
+					}
+
+					if err := json.Unmarshal(data, &item); err != nil {
+						req.respCh <- jsParserResp{err: fmt.Errorf("failed to unmarshal JSON to Item: %w", err)}
+						continue
+					}
+				} else {
+					req.respCh <- jsParserResp{err: fmt.Errorf("JS function returned null or undefined")}
+					continue
+				}
+				req.respCh <- jsParserResp{item: &item}
+			}
+		}
+	}()
+
+	return p
+}
+
+// 加载指定文件夹下的所有 JS 解析器插件
+func LoadPlugins(ctx context.Context, dir string) error {
+	entries, err := os.ReadDir(dir)
+	if err != nil {
+		return err
+	}
+
+	for _, e := range entries {
+		if filepath.Ext(e.Name()) != ".js" {
+			continue
+		}
+		scriptPath := filepath.Join(dir, e.Name())
+		code, err := os.ReadFile(scriptPath)
+		if err != nil {
+			return err
+		}
+
+		vm := goja.New()
+		vm.Set("registerParser", jsRegisterParser(vm))
+		// Inject some utils to vm
+		logger := log.FromContext(ctx).WithPrefix(fmt.Sprintf("[plugin|parser]/%s", e.Name()))
+		vm.Set("console", jsConsole(logger))
+		// http fetch funcs
+		vm.Set("ghttp", jsGhttp(vm))
+		// playwright fetch func
+		vm.Set("playwright", jsPlaywright(vm, logger))
+
+		if _, err := vm.RunString(string(code)); err != nil {
+			return fmt.Errorf("error loading plugin %s: %w", e.Name(), err)
+		}
+	}
+	return nil
+}
+
+var (
+	pluginNameMu sync.Map
+)
+
+func AddPlugin(ctx context.Context, code string, name string) error {
+	value, _ := pluginNameMu.LoadOrStore(name, &sync.Mutex{})
+	mu := value.(*sync.Mutex)
+	mu.Lock()
+	defer mu.Unlock()
+
+	return addPlugin(ctx, code, name)
+}
+
+func addPlugin(ctx context.Context, code string, name string) error {
+	logger := log.FromContext(ctx).WithPrefix(fmt.Sprintf("[plugin|parser]/%s", name))
+	vm := goja.New()
+	vm.Set("registerParser", jsRegisterParser(vm))
+	vm.Set("console", jsConsole(logger))
+	vm.Set("ghttp", jsGhttp(vm))
+	vm.Set("playwright", jsPlaywright(vm, logger))
+	if _, err := vm.RunString(code); err != nil {
+		return fmt.Errorf("error loading plugin %s: %w", name, err)
+	}
+	dir := "plugins"
+	configuredDirs := config.C().Parser.PluginDirs
+	if len(configuredDirs) > 0 {
+		dir = configuredDirs[0]
+	}
+	if err := os.MkdirAll(dir, 0755); err == nil {
+		pluginPath := filepath.Join(dir, name)
+		if err := os.WriteFile(pluginPath, []byte(code), 0644); err != nil {
+			logger.Warn("Failed to save plugin file: " + err.Error())
+		}
+	}
+	return nil
+}