view.go

package main

import (
	"context"
	"fmt"
	"strconv"

	"github.com/gdamore/tcell/v2"
	"github.com/mhutchinson/woodpecker/model"
	"github.com/rivo/tview"
)

type Callbacks interface {
	RefreshCheckpoint()
	GetLeaf(size, index uint64)
	PrevLeaf()
	NextLeaf()
	SelectLog(o string)
	IncWitnesses()
	DecWitnesses()
}

type View struct {
	Model     *model.ViewModel
	Callbacks Callbacks

	app        *tview.Application
	cpArea     *tview.TextView
	witArea    *tview.TextView
	mainArea   *tview.Pages
	leafPage   *tview.TextView
	logsPage   *tview.List
	errPage    *tview.TextView
	jumpPage   *tview.InputField
	bottomArea *tview.Pages
}

func NewView(cb Callbacks, m *model.ViewModel) View {
	app := tview.NewApplication()
	grid := tview.NewGrid()
	grid.SetRows(15, 0, 5).SetColumns(0)
	cpArea := tview.NewTextView()
	cpArea.SetBorder(true).SetTitle("Log Checkpoint")
	witnessedArea := tview.NewTextView()
	witnessedArea.SetBorder(true).SetTitle("Witnessed Checkpoint")

	mainArea := tview.NewPages()
	leafPage := tview.NewTextView()
	leafPage.SetBorder(true).SetTitle("No leaf loaded")
	logsPage := tview.NewList()
	logsPage.SetBorder(true).SetTitle("Choose a log to investigate")
	for i, o := range m.GetLogOrigins() {
		logsPage.AddItem(o, "", rune('a'+i), func() {
			cb.SelectLog(o)
		})
	}
	exitLogSelector := func() {
		mainArea.SwitchToPage("leaf")
		app.SetFocus(mainArea)
	}
	logsPage.AddItem("eXit", "eXplore the selected log", rune('x'), exitLogSelector)
	logsPage.SetInputCapture(func(event *tcell.EventKey) *tcell.EventKey {
		switch event.Key() {
		case tcell.KeyEnter:
			exitLogSelector()
			return nil
		case tcell.KeyEscape:
			exitLogSelector()
			return nil
		}
		return event
	})
	mainArea.AddPage("logs", logsPage, true, true)
	mainArea.AddPage("leaf", leafPage, true, true)

	bottomArea := tview.NewPages()
	errPage := tview.NewTextView()
	jumpPage := tview.NewInputField()
	jumpPage.SetLabel("Jump to index").SetFieldWidth(10).SetAcceptanceFunc(tview.InputFieldInteger).SetDoneFunc(func(key tcell.Key) {
		t := jumpPage.GetText()
		i, err := strconv.Atoi(t)
		if err != nil {
			return
		}
		cb.GetLeaf(m.GetCheckpoint().Size, uint64(i))
		bottomArea.SwitchToPage("errors")
		app.SetFocus(mainArea)
	})
	bottomArea.AddPage("jump", jumpPage, true, true)
	bottomArea.AddPage("errors", errPage, true, true)
	app.SetRoot(grid, true)

	cpFlex := tview.NewFlex()
	cpFlex.AddItem(cpArea, 0, 1, false)
	cpFlex.AddItem(witnessedArea, 0, 1, false)
	grid.AddItem(cpFlex, 0, 0, 1, 1, 0, 0, false)
	grid.AddItem(mainArea, 1, 0, 1, 1, 0, 0, false)
	grid.AddItem(bottomArea, 2, 0, 1, 1, 0, 0, false)

	v := View{
		Model:      m,
		Callbacks:  cb,
		app:        app,
		cpArea:     cpArea,
		witArea:    witnessedArea,
		mainArea:   mainArea,
		leafPage:   leafPage,
		logsPage:   logsPage,
		bottomArea: bottomArea,
		errPage:    errPage,
		jumpPage:   jumpPage,
	}
	return v
}

func (v View) Run(ctx context.Context) error {
	v.app.SetInputCapture(func(event *tcell.EventKey) *tcell.EventKey {
		switch event.Key() {
		case tcell.KeyLeft:
			v.Callbacks.PrevLeaf()
			return nil
		case tcell.KeyRight:
			v.Callbacks.NextLeaf()
			return nil
		}
		switch event.Rune() {
		case 'l':
			v.mainArea.SwitchToPage("logs")
			v.app.SetFocus(v.logsPage)
			return nil
		case 'W':
			v.Callbacks.DecWitnesses()
			return nil
		case 'w':
			v.Callbacks.IncWitnesses()
			return nil
		case 'g':
			v.bottomArea.SwitchToPage("jump")
			v.app.SetFocus(v.jumpPage)
			return nil
		case 'q':
			v.app.Stop()
		}
		return event
	})
	go func() {
		for {
			select {
			case <-ctx.Done():
				return
			case <-v.Model.Dirty:
				v.refreshFromModel()
				v.app.Draw()
			}
		}
	}()
	return v.app.Run()
}

func (v View) refreshFromModel() {
	cp := v.Model.GetCheckpoint()
	if cp != nil {
		text := string(cp.Raw)
		v.cpArea.SetText(text)
	}
	v.witArea.SetTitle(fmt.Sprintf("Witnessed Checkpoint (N=%d)", v.Model.GetWitnessN()))
	wit := v.Model.GetWitnessed()
	if wit != nil {
		text := fmt.Sprintf("Size: %d | Hash: %x", wit.Size, wit.Hash)
		wits := wit.Note.Sigs[1:]
		for _, w := range wits {
			text = fmt.Sprintf("%s\n%s", text, w.Name)
		}
		v.witArea.SetText(text)
	}

	v.leafPage.SetTitle(fmt.Sprintf("Leaf %d", v.Model.GetLeaf().Index))
	v.leafPage.SetText(string(v.Model.GetLeaf().Contents))

	if v.Model.GetError() != nil {
		v.errPage.SetText(fmt.Sprintf("Error: %v", v.Model.GetError()))
	} else {
		v.errPage.SetText("")
	}
}