@@ -0,0 +1,129 @@
+package manpages
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"time"
+
+	"gitlab.com/tozd/go/errors"
+	"go.alanpearce.eu/searchix/internal/config"
+	"go.alanpearce.eu/searchix/internal/fetcher/http"
+	"go.alanpearce.eu/x/log"
+)
+
+const basename = "manpage-urls.json"
+
+type URLMap struct {
+	path string
+
+	mtime  time.Time
+	logger *log.Logger
+	urlMap map[string]string
+}
+
+func New(cfg *config.Config, logger *log.Logger) *URLMap {
+	return &URLMap{
+		path:   filepath.Join(cfg.DataPath, basename),
+		logger: logger,
+	}
+}
+
+func (m *URLMap) Update(
+	ctx context.Context,
+	source *config.Source,
+) errors.E {
+	if !source.Manpages.Enable {
+		return errors.New("manpages not enabled for this source")
+	}
+
+	if source.Manpages.Path == "" {
+		return errors.New("manpages repo source path not configured")
+	}
+
+	url, err := makeManpageURL(source)
+	if err != nil {
+		return errors.WithMessage(err, "failed to join manpages URL")
+	}
+
+	m.logger.Debug("fetching manpages URL map", "url", url)
+	r, mtime, err := http.FetchFileIfNeeded(ctx, m.logger.Named("http"), m.mtime, url)
+	if err != nil {
+		return errors.WithMessage(err, "failed to fetch manpages")
+	}
+	defer r.Close()
+
+	if err := m.save(r); err != nil {
+		return errors.WithMessage(err, "failed to save manpages")
+	}
+
+	m.mtime = mtime
+
+	return nil
+}
+
+// Open loads the manpage URLs from the JSON file
+func (m *URLMap) Open() errors.E {
+	m.logger.Debug("opening manpages file", "path", m.path)
+
+	stat, err := os.Stat(m.path)
+	if err != nil {
+		return errors.WithMessagef(err, "failed to stat manpages file: %s", m.path)
+	}
+
+	data, err := os.ReadFile(m.path)
+	if err != nil {
+		return errors.WithMessage(err, "failed to read manpages file")
+	}
+
+	m.mtime = stat.ModTime()
+
+	m.urlMap = make(map[string]string)
+	if err := json.Unmarshal(data, &m.urlMap); err != nil {
+		return errors.WithMessage(err, "failed to parse manpages JSON")
+	}
+
+	m.logger.Debug("loaded manpages data", "urls", len(m.urlMap))
+
+	return nil
+}
+
+func (m *URLMap) save(r io.Reader) errors.E {
+	m.logger.Debug("saving manpages file", "path", m.path)
+
+	f, err := os.Create(m.path)
+	if err != nil {
+		return errors.WithMessage(err, "failed to create manpages file")
+	}
+	defer f.Close()
+
+	if _, err := io.Copy(f, r); err != nil {
+		return errors.WithMessage(err, "failed to write manpages file")
+	}
+
+	return nil
+}
+
+func (m *URLMap) Get(section string, page string) (string, bool) {
+	key := fmt.Sprintf("%s(%s)", page, section)
+
+	m.logger.Debug("getting manpage URL", "key", key)
+	url, ok := m.urlMap[key]
+	if !ok {
+		return "", false
+	}
+
+	return url, true
+}
+
+func makeManpageURL(source *config.Source) (string, errors.E) {
+	url, err := source.Repo.GetRawFileURL(source.Manpages.Path)
+	if err != nil {
+		return "", errors.WithMessage(err, "failed to join manpage URL")
+	}
+
+	return url, nil
+}