Move wisski instance code to separate package

internal/wisski/prefix.go

@@ -0,0 +1,144 @@
+package wisski
+
+import (
+	"bufio"
+	"path/filepath"
+	"strings"
+
+	"github.com/FAU-CDI/wisski-distillery/internal/component/meta"
+	"github.com/FAU-CDI/wisski-distillery/pkg/fsx"
+	"github.com/tkw1536/goprogram/lib/collection"
+
+	_ "embed"
+)
+
+// NoPrefix checks if this WissKI instance is excluded from generating prefixes.
+// TODO: Move this to the database!
+func (wisski *WissKI) NoPrefix() bool {
+	return fsx.IsFile(wisski.Core.Environment, filepath.Join(wisski.FilesystemBase, "prefixes.skip"))
+}
+
+//go:embed php/list_uri_prefixes.php
+var listURIPrefixesPHP string
+
+// Prefixes returns the prefixes applying to this WissKI
+//
+// server is an optional server to fetch prefixes from.
+// server may be nil.
+func (wisski *WissKI) Prefixes(server *PHPServer) ([]string, error) {
+	prefixes, err := wisski.dbPrefixes(server)
+	if err != nil {
+		return nil, err
+	}
+
+	prefixes2, err := wisski.filePrefixes()
+	if err != nil {
+		return nil, err
+	}
+
+	return append(prefixes, prefixes2...), nil
+}
+
+func (wisski *WissKI) dbPrefixes(server *PHPServer) (prefixes []string, err error) {
+	// get all the ugly prefixes
+	err = wisski.ExecPHPScript(server, &prefixes, listURIPrefixesPHP, "list_prefixes")
+	if err != nil {
+		return nil, err
+	}
+
+	// filter out sequential prefixes
+	prefixes = collection.NonSequential(prefixes, func(prev, now string) bool {
+		return strings.HasPrefix(now, prev)
+	})
+
+	// load the list of blocked prefixes
+	blocks, err := wisski.blockedPrefixes()
+	if err != nil {
+		return nil, err
+	}
+
+	// filter out blocked prefixes
+	return collection.Filter(prefixes, func(uri string) bool { return !hasAnyPrefix(uri, blocks) }), nil
+}
+
+func (wisski *WissKI) blockedPrefixes() ([]string, error) {
+	// open the resolver block file
+	file, err := wisski.Core.Environment.Open(wisski.Core.Config.SelfResolverBlockFile)
+	if err != nil {
+		return nil, err
+	}
+
+	var lines []string
+
+	// read all the lines that aren't a comment!
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if line == "" || strings.HasPrefix(line, "//") || strings.HasPrefix(line, "#") {
+			continue
+		}
+		lines = append(lines, line)
+	}
+
+	// check if there was an error
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	// and done!
+	return lines, nil
+}
+
+func hasAnyPrefix(candidate string, prefixes []string) bool {
+	return collection.Any(
+		prefixes,
+		func(prefix string) bool {
+			return strings.HasPrefix(candidate, prefix)
+		},
+	)
+}
+
+func (wisski *WissKI) filePrefixes() (prefixes []string, err error) {
+	path := filepath.Join(wisski.FilesystemBase, "prefixes")
+	if !fsx.IsFile(wisski.Core.Environment, path) {
+		return nil, nil
+	}
+
+	file, err := wisski.Core.Environment.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if len(line) == 0 || line[0] == '#' {
+			continue
+		}
+		prefixes = append(prefixes, line)
+	}
+
+	if scanner.Err() != nil {
+		return nil, scanner.Err()
+	}
+	return prefixes, nil
+}
+
+// CACHING
+
+var prefix = meta.StorageFor[string]("prefix")
+
+// Prefixes returns the cached prefixes from the given instance
+func (wisski *WissKI) PrefixesCached() (results []string, err error) {
+	return prefix(wisski.storage()).GetAll()
+}
+
+// UpdatePrefixes updates the cached prefixes of this instance
+func (wisski *WissKI) UpdatePrefixes() error {
+	prefixes, err := wisski.Prefixes(nil)
+	if err != nil {
+		return err
+	}
+	return prefix(wisski.storage()).SetAll(prefixes...)
+}