1 files changed, 281 insertions, 0 deletions
diff --git a/packages/tui/internal/components/fileviewer/fileviewer.go b/packages/tui/internal/components/fileviewer/fileviewer.go
new file mode 100644
index 000000000..6627bc3f0
--- /dev/null
+++ b/packages/tui/internal/components/fileviewer/fileviewer.go
@@ -0,0 +1,281 @@
+package fileviewer
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/charmbracelet/bubbles/v2/viewport"
+	tea "github.com/charmbracelet/bubbletea/v2"
+
+	"github.com/sst/opencode/internal/app"
+	"github.com/sst/opencode/internal/commands"
+	"github.com/sst/opencode/internal/components/dialog"
+	"github.com/sst/opencode/internal/components/diff"
+	"github.com/sst/opencode/internal/layout"
+	"github.com/sst/opencode/internal/styles"
+	"github.com/sst/opencode/internal/theme"
+	"github.com/sst/opencode/internal/util"
+)
+
+type DiffStyle int
+
+const (
+	DiffStyleSplit DiffStyle = iota
+	DiffStyleUnified
+)
+
+type Model struct {
+	app           *app.App
+	width, height int
+	viewport      viewport.Model
+	filename      *string
+	content       *string
+	isDiff        *bool
+	diffStyle     DiffStyle
+}
+
+type fileRenderedMsg struct {
+	content string
+}
+
+func New(app *app.App) Model {
+	vp := viewport.New()
+	m := Model{
+		app:       app,
+		viewport:  vp,
+		diffStyle: DiffStyleUnified,
+	}
+	if app.State.SplitDiff {
+		m.diffStyle = DiffStyleSplit
+	}
+	return m
+}
+
+func (m Model) Init() tea.Cmd {
+	return m.viewport.Init()
+}
+
+func (m Model) Update(msg tea.Msg) (Model, tea.Cmd) {
+	var cmds []tea.Cmd
+
+	switch msg := msg.(type) {
+	case fileRenderedMsg:
+		m.viewport.SetContent(msg.content)
+		return m, util.CmdHandler(app.FileRenderedMsg{
+			FilePath: *m.filename,
+		})
+	case dialog.ThemeSelectedMsg:
+		return m, m.render()
+	case tea.KeyMsg:
+		switch msg.String() {
+		// TODO
+		}
+	}
+
+	vp, cmd := m.viewport.Update(msg)
+	m.viewport = vp
+	cmds = append(cmds, cmd)
+
+	return m, tea.Batch(cmds...)
+}
+
+func (m Model) View() string {
+	if !m.HasFile() {
+		return ""
+	}
+
+	header := *m.filename
+	header = styles.NewStyle().
+		Padding(1, 2).
+		Width(m.width).
+		Background(theme.CurrentTheme().BackgroundElement()).
+		Foreground(theme.CurrentTheme().Text()).
+		Render(header)
+
+	t := theme.CurrentTheme()
+
+	close := m.app.Key(commands.FileCloseCommand)
+	diffToggle := m.app.Key(commands.FileDiffToggleCommand)
+	if m.isDiff == nil || *m.isDiff == false {
+		diffToggle = ""
+	}
+	layoutToggle := m.app.Key(commands.MessagesLayoutToggleCommand)
+
+	background := t.Background()
+	footer := layout.Render(
+		layout.FlexOptions{
+			Background: &background,
+			Direction:  layout.Row,
+			Justify:    layout.JustifyCenter,
+			Align:      layout.AlignStretch,
+			Width:      m.width - 2,
+			Gap:        5,
+		},
+		layout.FlexItem{
+			View: close,
+		},
+		layout.FlexItem{
+			View: layoutToggle,
+		},
+		layout.FlexItem{
+			View: diffToggle,
+		},
+	)
+	footer = styles.NewStyle().Background(t.Background()).Padding(0, 1).Render(footer)
+
+	return header + "\n" + m.viewport.View() + "\n" + footer
+}
+
+func (m *Model) Clear() (Model, tea.Cmd) {
+	m.filename = nil
+	m.content = nil
+	m.isDiff = nil
+	return *m, m.render()
+}
+
+func (m *Model) ToggleDiff() (Model, tea.Cmd) {
+	switch m.diffStyle {
+	case DiffStyleSplit:
+		m.diffStyle = DiffStyleUnified
+	default:
+		m.diffStyle = DiffStyleSplit
+	}
+	return *m, m.render()
+}
+
+func (m *Model) DiffStyle() DiffStyle {
+	return m.diffStyle
+}
+
+func (m Model) HasFile() bool {
+	return m.filename != nil && m.content != nil
+}
+
+func (m Model) Filename() string {
+	if m.filename == nil {
+		return ""
+	}
+	return *m.filename
+}
+
+func (m *Model) SetSize(width, height int) (Model, tea.Cmd) {
+	if m.width != width || m.height != height {
+		m.width = width
+		m.height = height
+		m.viewport.SetWidth(width)
+		m.viewport.SetHeight(height - 4)
+		return *m, m.render()
+	}
+	return *m, nil
+}
+
+func (m *Model) SetFile(filename string, content string, isDiff bool) (Model, tea.Cmd) {
+	m.filename = &filename
+	m.content = &content
+	m.isDiff = &isDiff
+	return *m, m.render()
+}
+
+func (m *Model) render() tea.Cmd {
+	if m.filename == nil || m.content == nil {
+		m.viewport.SetContent("")
+		return nil
+	}
+
+	return func() tea.Msg {
+		t := theme.CurrentTheme()
+		var rendered string
+
+		if m.isDiff != nil && *m.isDiff {
+			diffResult := ""
+			var err error
+			if m.diffStyle == DiffStyleSplit {
+				diffResult, err = diff.FormatDiff(
+					*m.filename,
+					*m.content,
+					diff.WithWidth(m.width),
+				)
+			} else if m.diffStyle == DiffStyleUnified {
+				diffResult, err = diff.FormatUnifiedDiff(
+					*m.filename,
+					*m.content,
+					diff.WithWidth(m.width),
+				)
+			}
+			if err != nil {
+				rendered = styles.NewStyle().
+					Foreground(t.Error()).
+					Render(fmt.Sprintf("Error rendering diff: %v", err))
+			} else {
+				rendered = strings.TrimRight(diffResult, "\n")
+			}
+		} else {
+			rendered = util.RenderFile(
+				*m.filename,
+				*m.content,
+				m.width,
+			)
+		}
+
+		rendered = styles.NewStyle().
+			Width(m.width).
+			Background(t.BackgroundPanel()).
+			Render(rendered)
+
+		return fileRenderedMsg{
+			content: rendered,
+		}
+	}
+}
+
+func (m *Model) ScrollTo(line int) {
+	m.viewport.SetYOffset(line)
+}
+
+func (m *Model) ScrollToBottom() {
+	m.viewport.GotoBottom()
+}
+
+func (m *Model) ScrollToTop() {
+	m.viewport.GotoTop()
+}
+
+func (m *Model) PageUp() (Model, tea.Cmd) {
+	m.viewport.ViewUp()
+	return *m, nil
+}
+
+func (m *Model) PageDown() (Model, tea.Cmd) {
+	m.viewport.ViewDown()
+	return *m, nil
+}
+
+func (m *Model) HalfPageUp() (Model, tea.Cmd) {
+	m.viewport.HalfViewUp()
+	return *m, nil
+}
+
+func (m *Model) HalfPageDown() (Model, tea.Cmd) {
+	m.viewport.HalfViewDown()
+	return *m, nil
+}
+
+func (m Model) AtTop() bool {
+	return m.viewport.AtTop()
+}
+
+func (m Model) AtBottom() bool {
+	return m.viewport.AtBottom()
+}
+
+func (m Model) ScrollPercent() float64 {
+	return m.viewport.ScrollPercent()
+}
+
+func (m Model) TotalLineCount() int {
+	return m.viewport.TotalLineCount()
+}
+
+func (m Model) VisibleLineCount() int {
+	return m.viewport.VisibleLineCount()
+}