gitlink-cli/cmd/interactive/repl.go

package interactive

import (
	"fmt"
	"strings"

	"github.com/charmbracelet/bubbles/spinner"
	"github.com/charmbracelet/bubbles/textinput"
	"github.com/charmbracelet/bubbles/viewport"
	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/lipgloss"

	"github.com/gitlink-org/gitlink-cli/shortcuts"
	"github.com/gitlink-org/gitlink-cli/shortcuts/common"
)

// replState tracks the current state of the REPL.
type replState int

const (
	stateInput    replState = iota // waiting for user text input
	statePalette                   // command palette is active
	stateForm                      // parameter form is active
	stateExecuting                 // executing a command
	stateError                     // showing an error
	stateOutput                    // scrolling through long command output
)

// execResultMsg is sent when command execution completes.
type execResultMsg struct {
	group    string
	shortcut *common.Shortcut
	args     map[string]string
	output   string
	err      error
}

// replModel is the main REPL state machine.
type replModel struct {
	state       replState
	input       textinput.Model
	palette     paletteModel
	form        formModel
	executor    Executor
	shortcuts   map[string][]*common.Shortcut
	descs       map[string]string
	lastOutput  string
	lastError   string
	spinner     spinner.Model
	viewport    viewport.Model // 可滚动查看器，用于浏览超出一屏的长输出
	owner       string
	repo        string
	width       int
	height      int
	quitting    bool
	showWelcome bool
}

var promptStyle = lipgloss.NewStyle().Bold(true).Foreground(lipgloss.Color("6"))
var successStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("10"))
var errorStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("9")).Bold(true)
var welcomeStyle = lipgloss.NewStyle().Faint(true)

// newReplModel creates a new REPL model.
func newReplModel(owner, repo string) replModel {
	ti := textinput.New()
	ti.Prompt = buildPrompt(owner, repo)
	ti.Focus()
	ti.Width = 60

	sp := spinner.New()
	sp.Spinner = spinner.Dot
	sp.Style = lipgloss.NewStyle().Foreground(lipgloss.Color("6"))

	return replModel{
		state:       stateInput,
		input:       ti,
		executor:    Executor{},
		shortcuts:   shortcuts.GetAllShortcuts(),
		descs:       shortcuts.GetDescriptions(),
		spinner:     sp,
		owner:       owner,
		repo:        repo,
		showWelcome: true,
	}
}

// buildPrompt creates the prompt string.
func buildPrompt(owner, repo string) string {
	if owner != "" && repo != "" {
		return fmt.Sprintf("gitlink (%s/%s)> ", owner, repo)
	}
	return "gitlink> "
}

// Init initializes the REPL.
func (m replModel) Init() tea.Cmd {
	return textinput.Blink
}

// Update is the main message dispatcher.
func (m replModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg.(type) {
	case tea.WindowSizeMsg:
		wmsg := msg.(tea.WindowSizeMsg)
		m.width = wmsg.Width
		m.height = wmsg.Height
		// 保持 viewport 尺寸与终端同步（底部留 2 行给提示符/帮助行）。
		m.viewport.Width = wmsg.Width
		m.viewport.Height = wmsg.Height - 2
		return m, nil
	}

	switch m.state {
	case stateInput:
		return m.updateInput(msg)
	case statePalette:
		return m.updatePalette(msg)
	case stateForm:
		return m.updateForm(msg)
	case stateExecuting:
		return m.updateExecuting(msg)
	case stateError:
		return m.updateError(msg)
	case stateOutput:
		return m.updateOutput(msg)
	}

	return m, nil
}

// updateInput handles the text input state.
func (m replModel) updateInput(msg tea.Msg) (tea.Model, tea.Cmd) {
	keyMsg, isKey := msg.(tea.KeyMsg)
	if isKey {
		switch keyMsg.Type {
		case tea.KeyRunes:
			// Trigger the command palette immediately when the user types "/"
			// as the first character of a fresh input — no Enter required.
			if m.input.Value() == "" && len(keyMsg.Runes) > 0 && keyMsg.Runes[0] == '/' {
				m.showWelcome = false
				m.input.SetValue("")
				m.palette = newPaletteModel(m.shortcuts, m.descs, m.width, m.height)
				// Carry any extra characters typed alongside "/" as the initial query.
				if len(keyMsg.Runes) > 1 {
					query := string(keyMsg.Runes[1:])
					m.palette.search.SetValue(query)
					m.palette.filterItems(query)
				}
				m.state = statePalette
				return m, nil
			}

		case tea.KeyEnter:
			val := strings.TrimSpace(m.input.Value())
			m.input.SetValue("")
			m.showWelcome = false

			if val == "" {
				return m, nil
			}

			// Exit commands
			if val == "exit" || val == "quit" {
				m.quitting = true
				return m, tea.Quit
			}

			// Palette mode (also reachable via "/query" + Enter)
			if strings.HasPrefix(val, "/") {
				m.palette = newPaletteModel(m.shortcuts, m.descs, m.width, m.height)
				if len(val) > 1 {
					query := val[1:]
					m.palette.search.SetValue(query)
					m.palette.filterItems(query)
				}
				m.state = statePalette
				return m, nil
			}

			// Direct command: "group +cmd ..."
			group, cmd, flagStr, ok := parseDirectCommand(val)
			if ok {
				s, found := findShortcut(m.shortcuts, group, cmd)
				if !found {
					m.lastError = fmt.Sprintf("Unknown command: %s +%s", group, cmd)
					m.state = stateError
					return m, nil
				}

				shortMap := buildShortMap(s)
				args := parseFlagString(flagStr, shortMap)
				missing := missingRequiredFlags(s, args)

				if len(missing) > 0 {
					// Show form with prefilled values
					m.form = newFormModel(group, s, m.width, m.height, args)
					m.state = stateForm
					return m, nil
				}

				// Execute directly
				m.state = stateExecuting
				return m, m.executeCommand(group, s, args)
			}

			// Unrecognized input
			m.lastError = fmt.Sprintf("Unknown input: %q\nType a command like \"issue +list\" or \"/\" to open the command palette.", val)
			m.state = stateError
			return m, nil

		case tea.KeyCtrlD, tea.KeyCtrlC:
			m.quitting = true
			return m, tea.Quit
		}
	}

	// Forward to text input
	var cmd tea.Cmd
	m.input, cmd = m.input.Update(msg)
	return m, cmd
}

// executeCommand returns a tea.Cmd that runs a shortcut asynchronously.
func (m replModel) executeCommand(group string, s *common.Shortcut, args map[string]string) tea.Cmd {
	return func() tea.Msg {
		output, err := m.executor.Execute(s, args)
		return execResultMsg{
			group:    group,
			shortcut: s,
			args:     args,
			output:   output,
			err:      err,
		}
	}
}

// updatePalette delegates to the palette sub-component.
func (m replModel) updatePalette(msg tea.Msg) (tea.Model, tea.Cmd) {
	var cmd tea.Cmd
	m.palette, cmd = m.palette.Update(msg)

	if m.palette.quitting {
		m.palette.quitting = false
		m.state = stateInput
		return m, textinput.Blink
	}

	if m.palette.result != nil {
		result := m.palette.result
		s := result.Shortcut

		// Open the form whenever the command has ANY flags — not just required
		// ones. Many commands have "at-least-one-of" parameters (e.g. branch
		// +batch-protect needs --names OR --from) that can't be marked Required
		// individually, so skipping the form for "optional-only" commands left
		// users unable to supply them and the command failed at runtime.
		// Commands with no flags at all execute directly.
		if len(s.Flags) > 0 {
			m.form = newFormModel(result.Group, s, m.width, m.height, nil)
			m.state = stateForm
			return m, nil
		}

		// No flags → execute directly
		m.state = stateExecuting
		return m, tea.Batch(m.executeCommand(result.Group, s, map[string]string{}), m.spinner.Tick)
	}

	return m, cmd
}

// updateForm delegates to the form sub-component.
func (m replModel) updateForm(msg tea.Msg) (tea.Model, tea.Cmd) {
	var cmd tea.Cmd
	m.form, cmd = m.form.Update(msg)

	if m.form.cancelled {
		m.form.cancelled = false
		m.state = stateInput
		return m, textinput.Blink
	}

	if m.form.submitted {
		args := m.form.values
		group := m.form.group
		s := m.form.shortcut
		m.form.submitted = false
		m.state = stateExecuting
		return m, m.executeCommand(group, s, args)
	}

	return m, cmd
}

// updateExecuting waits for the execResultMsg.
func (m replModel) updateExecuting(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case execResultMsg:
		if msg.err != nil {
			m.lastError = formatInteractiveError(msg.group, msg.shortcut, msg.err)
			m.lastOutput = ""
			m.state = stateError
			return m, nil
		}
		display := formatCommandDisplay(msg.group, msg.shortcut, msg.args)
		content := fmt.Sprintf("  ✓ 执行: %s\n\n%s", display, msg.output)
		// 输出超过可用高度（留 4 行给提示符与边距）时进入可滚动查看器，
		// 否则保持原行为：直接显示在输入状态。
		lineCount := strings.Count(content, "\n") + 1
		if m.height > 0 && lineCount > m.height-4 {
			m.viewport = viewport.New(m.width, m.height-2)
			m.viewport.SetContent(content)
			m.viewport.GotoTop()
			m.lastOutput = ""
			m.lastError = ""
			m.state = stateOutput
			return m, nil
		}
		m.lastOutput = content
		m.lastError = ""
		m.state = stateInput
		m.input.Focus()
		return m, textinput.Blink

	case spinner.TickMsg:
		var cmd tea.Cmd
		m.spinner, cmd = m.spinner.Update(msg)
		return m, cmd
	}

	return m, nil
}

// updateError waits for Enter to return to input state.
func (m replModel) updateError(msg tea.Msg) (tea.Model, tea.Cmd) {
	keyMsg, isKey := msg.(tea.KeyMsg)
	if isKey {
		switch keyMsg.Type {
		case tea.KeyEnter, tea.KeyEsc:
			m.lastError = ""
			m.state = stateInput
			m.input.Focus()
			return m, textinput.Blink
		case tea.KeyCtrlD, tea.KeyCtrlC:
			m.quitting = true
			return m, tea.Quit
		}
	}
	return m, nil
}

// updateOutput 处理输出查看器状态：用方向键/PageUp/PageDown 浏览长输出，
// 按 q 或 Esc 返回输入状态。
func (m replModel) updateOutput(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case tea.KeyMsg:
		switch msg.Type {
		case tea.KeyEsc, tea.KeyCtrlC:
			m.state = stateInput
			m.input.Focus()
			return m, textinput.Blink
		case tea.KeyRunes:
			// q / Q 返回输入
			if len(msg.Runes) > 0 && (msg.Runes[0] == 'q' || msg.Runes[0] == 'Q') {
				m.state = stateInput
				m.input.Focus()
				return m, textinput.Blink
			}
		}
	}
	// 其余按键（方向键、PageUp/Down、Home/End）转发给 viewport，
	// viewport 内置响应这些按键，无需手动处理。
	var cmd tea.Cmd
	m.viewport, cmd = m.viewport.Update(msg)
	return m, cmd
}

// View renders the REPL based on current state.
func (m replModel) View() string {
	if m.quitting {
		return ""
	}

	switch m.state {
	case stateInput:
		var sb strings.Builder
		if m.showWelcome {
			sb.WriteString(welcomeStyle.Render("Welcome to gitlink-cli interactive mode."))
			sb.WriteString("\n")
			sb.WriteString(welcomeStyle.Render("Type / to open the command palette, \"exit\" or Ctrl+D to quit."))
			sb.WriteString("\n\n")
		}
		if m.lastOutput != "" {
			sb.WriteString(successStyle.Render(m.lastOutput))
			sb.WriteString("\n")
		}
		sb.WriteString(m.input.View())
		return sb.String()

	case statePalette:
		return m.palette.View()

	case stateForm:
		return m.form.View()

	case stateExecuting:
		return fmt.Sprintf("\n  %s Executing command...\n", m.spinner.View())

	case stateError:
		var sb strings.Builder
		sb.WriteString("\n")
		sb.WriteString(errorStyle.Render(m.lastError))
		sb.WriteString("\n\n")
		sb.WriteString(formHelpStyle.Render("  Press Enter to continue"))
		sb.WriteString("\n")
		return sb.String()

	case stateOutput:
		return m.viewport.View() + "\n" +
			formHelpStyle.Render("  ↑↓/PgUp/PgDn 滚动  q/Esc 返回")
	}

	return ""
}

// Run starts the interactive REPL.
func Run(owner, repo string) error {
	m := newReplModel(owner, repo)
	p := tea.NewProgram(m, tea.WithAltScreen())
	_, err := p.Run()
	return err
}