tours

1 files changed, 214 insertions, 0 deletions

diff --git a/tour.go b/tour.go
new file mode 100644
index 0000000..d74bef4
--- /dev/null
+++ b/tour.go
@@ -0,0 +1,214 @@
+package main
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"net/url"
+	"slices"
+	"strconv"
+	"strings"
+)
+
+var (
+	ErrEndOfTour      = errors.New("you've hit the end of the tour")
+	ErrStartOfTour    = errors.New("you're at the start of the tour")
+	ErrInvalidTourPos = errors.New("that's not a valid tour link")
+)
+
+type Tour struct {
+	Index int
+	Links []*url.URL
+}
+
+func parseURLs(state *BrowserState, defaultScheme, str string) ([]*url.URL, error) {
+	urls := []*url.URL{}
+
+	if str == "*" {
+		for _, link := range state.Links {
+			urls = append(urls, state.Url.ResolveReference(link.Target))
+		}
+		return urls, nil
+	}
+
+	if i := strings.IndexByte(str, '-'); i > 0 {
+		start, e1 := strconv.Atoi(str[:i])
+		end, e2 := strconv.Atoi(str[i+1:])
+		if e1 == nil && e2 == nil && end >= start && start >= 0 && start < len(state.Links) && end < len(state.Links) {
+			for _, link := range state.Links[start : end+1] {
+				urls = append(urls, state.Url.ResolveReference(link.Target))
+			}
+			return urls, nil
+		}
+	}
+
+	u, _, err := parseURL(str, state, defaultScheme)
+	if err != nil {
+		return nil, err
+	}
+	return []*url.URL{u}, nil
+}
+
+func TourAdd(state *BrowserState, conf *Config, targets []string) error {
+	newurls := []*url.URL{}
+	for _, target := range targets {
+		urls, err := parseURLs(state, conf.DefaultScheme, target)
+		if err != nil {
+			return err
+		}
+		newurls = append(newurls, urls...)
+	}
+
+	state.CurrentTour.Links = append(state.CurrentTour.Links, newurls...)
+
+	if state.CurrentTour != &state.DefaultTour {
+		return saveTours(state.NamedTours)
+	}
+	return nil
+}
+
+func TourAddNext(state *BrowserState, conf *Config, targets []string) error {
+	newurls := []*url.URL{}
+	for _, target := range targets {
+		urls, err := parseURLs(state, conf.DefaultScheme, target)
+		if err != nil {
+			return err
+		}
+		newurls = append(newurls, urls...)
+	}
+
+	state.CurrentTour.Links = slices.Insert(
+		state.CurrentTour.Links,
+		state.CurrentTour.Index,
+		newurls...,
+	)
+
+	if state.CurrentTour != &state.DefaultTour {
+		return saveTours(state.NamedTours)
+	}
+	return nil
+}
+
+func TourShow(state *BrowserState) error {
+	tour := state.CurrentTour
+	buf := &bytes.Buffer{}
+	for i, link := range tour.Links {
+		mark := ""
+		if i == tour.Index-1 {
+			mark = "* "
+		}
+		if _, err := fmt.Fprintf(buf, "%s%d %s\n", mark, i, link.String()); err != nil {
+			return err
+		}
+	}
+
+	state.Modal = buf.Bytes()
+	if len(state.Modal) == 0 {
+		state.Modal = []byte("(empty)\n")
+	}
+	return Print(state)
+}
+
+func TourNext(state *BrowserState, conf *Config) error {
+	tour := state.CurrentTour
+	if tour.Index >= len(tour.Links) || len(tour.Links) == 0 {
+		return ErrEndOfTour
+	}
+	page := tour.Links[tour.Index]
+	tour.Index += 1
+
+	return Navigate(state, page, -1, conf)
+}
+
+func TourPrevious(state *BrowserState, conf *Config) error {
+	tour := state.CurrentTour
+	if tour.Index <= 0 {
+		return ErrStartOfTour
+	}
+	tour.Index -= 1
+	if tour.Index <= 0 {
+		return ErrStartOfTour
+	}
+	page := tour.Links[tour.Index-1]
+
+	return Navigate(state, page, -1, conf)
+}
+
+func TourClear(state *BrowserState) error {
+	state.CurrentTour.Index = 0
+	state.CurrentTour.Links = nil
+
+	if state.CurrentTour != &state.DefaultTour {
+		return saveTours(state.NamedTours)
+	}
+	return nil
+}
+
+func TourList(state *BrowserState) error {
+	buf := &bytes.Buffer{}
+	mark := ""
+	if state.CurrentTour == &state.DefaultTour {
+		mark = "* "
+	}
+	if _, err := fmt.Fprintf(buf, "%s(default): %d links\n", mark, len(state.DefaultTour.Links)); err != nil {
+		return err
+	}
+	for name, tour := range state.NamedTours {
+		mark = ""
+		if tour == state.CurrentTour {
+			mark = "* "
+		}
+		if _, err := fmt.Fprintf(buf, "%s%s: %d links\n", mark, name, len(tour.Links)); err != nil {
+			return err
+		}
+	}
+
+	state.Modal = buf.Bytes()
+	return Print(state)
+}
+
+func TourGo(state *BrowserState, conf *Config, pos string) error {
+	tour := state.CurrentTour
+
+	i, _ := strconv.Atoi(pos)
+	if i < 0 || i >= len(tour.Links) {
+		return ErrInvalidTourPos
+	}
+
+	tour.Index = i + 1
+	return Navigate(state, tour.Links[i], -1, conf)
+}
+
+func TourSet(state *BrowserState, name string) error {
+	tour, err := findTour(state, name)
+	if err == nil {
+		state.CurrentTour = tour
+	}
+	return err
+}
+
+func findTour(state *BrowserState, prefix string) (*Tour, error) {
+	if prefix == "" {
+		return &state.DefaultTour, nil
+	}
+
+	found := 0
+	var value *Tour
+	for name, tour := range state.NamedTours {
+		if strings.HasPrefix(name, prefix) {
+			found += 1
+			value = tour
+		}
+	}
+
+	switch found {
+	case 0:
+		tour := &Tour{}
+		state.NamedTours[prefix] = tour
+		return tour, nil
+	case 1:
+		return value, nil
+	default:
+		return nil, fmt.Errorf("too ambiguous - found %d matching tours", found)
+	}
+}