package internal

import tea "charm.land/bubbletea/v2"

// --- 按键分发 ---

func (m *Model) handleKey(s string) (*Model, tea.Cmd) {
	// 编辑标题时优先走输入处理，避免 q/1/2/u 等被全局拦截
	if m.editTitleMode {
		return m.handleEditTitleInput(s)
	}

	switch s {
	case "q", "ctrl+c":
		return m, tea.Quit
	case "u":
		if m.update.Available && !m.update.Updating {
			m.update.Updating = true
			return m, SelfUpdateCmd(m.update.DownloadURL, m.update.SHA256, m.update.NewVersion)
		}
	}

	// Tab 快捷切换: 1=工作空间 2=历史对话 3=技能
	if s == "1" {
		m.editTitleMode = false
		m.editTitleBuf = ""
		if m.IsHistoryTab() || m.IsSkillsTab() {
			m.activeGroup = 0
			m.resetCursor()
			m.wsFocus = 1
		}
		return m, nil
	}
	if s == "2" {
		if !m.IsHistoryTab() {
			m.activeGroup = len(Groups) // HISTORY
			m.resetCursor()
			m.wsFocus = 1
			return m, m.onTabSwitch()
		}
		return m, nil
	}
	if s == "3" {
		if !m.IsSkillsTab() {
			m.activeGroup = len(Groups) + 1 // SKILLS
			m.resetCursor()
			m.wsFocus = 1
			return m, m.onSkillsTabSwitch()
		}
		return m, nil
	}

	if m.IsSkillsTab() {
		return m.handleSkillsKey(s)
	}
	if m.IsHistoryTab() {
		return m.handleHistoryKey(s)
	}
	return m.handleWorkspaceKey(s)
}

func (m *Model) onTabSwitch() tea.Cmd {
	if !m.IsHistoryTab() || m.history.Scanning {
		return nil
	}
	m.history.Scanning = true
	return ScanSessionsCmd()
}

func (m *Model) onSkillsTabSwitch() tea.Cmd {
	if m.Skills.Loaded {
		return nil
	}
	m.Skills.Scanning = true
	return ScanSkillsCmd()
}

// --- 技能 tab 按键 ---

func (m *Model) handleSkillsKey(s string) (*Model, tea.Cmd) {
	switch s {
	case "up", "k":
		switch m.Skills.FocusPanel {
		case 0:
			m.moveSkillsSkill(-1)
		case 1:
			m.moveSkillsFile(-1)
		case 2:
			m.scrollSkillContent(-1)
		}
	case "down", "j":
		switch m.Skills.FocusPanel {
		case 0:
			m.moveSkillsSkill(1)
		case 1:
			m.moveSkillsFile(1)
		case 2:
			m.scrollSkillContent(1)
		}
	case "pgup":
		if m.Skills.FocusPanel == 2 {
			m.scrollSkillContent(-10)
		}
	case "pgdown":
		if m.Skills.FocusPanel == 2 {
			m.scrollSkillContent(10)
		}
	case "tab", "right", "l":
		// 进内容面板需已加载内容
		if m.Skills.FocusPanel < 1 {
			m.Skills.FocusPanel = 1
			m.autoLoadCurrentFile()
		} else if m.Skills.FocusPanel == 1 && m.Skills.ContentPath != "" {
			m.Skills.FocusPanel = 2
		}
	case "shift+tab", "left", "h":
		if m.Skills.FocusPanel > 0 {
			m.Skills.FocusPanel--
		}
	case "enter":
		switch m.Skills.FocusPanel {
		case 0:
			m.Skills.FocusPanel = 1
			m.Skills.FileCur = 0
			m.autoLoadCurrentFile()
		case 1:
			fn := m.currentFlatNode()
			if fn != nil {
				if fn.IsDir {
					fn.Expanded = !fn.Expanded
					flat := m.skillsFlattened()
					if m.Skills.FileCur >= len(flat) {
						m.Skills.FileCur = len(flat) - 1
					}
				} else {
					m.loadSkillContent(fn.Path)
					m.Skills.FocusPanel = 2 // 打开文件即聚焦内容，便于滚动
				}
			}
		}
	case "r", "f5":
		m.Skills.Loaded = false
		m.Skills.Scanning = true
		return m, ScanSkillsCmd()
	}
	return m, nil
}

// scrollSkillContent 滚动内容面板，边界由 View 层按实际高度再夹紧
func (m *Model) scrollSkillContent(dir int) {
	m.Skills.ContentScroll += dir
	if m.Skills.ContentScroll < 0 {
		m.Skills.ContentScroll = 0
	}
}

// autoLoadCurrentFile 若当前文件树光标停在文件上，自动加载其内容
func (m *Model) autoLoadCurrentFile() {
	if fn := m.currentFlatNode(); fn != nil && !fn.IsDir {
		m.loadSkillContent(fn.Path)
	}
}

func (m *Model) moveSkillsSkill(dir int) {
	if len(m.Skills.Skills) == 0 {
		return
	}
	m.Skills.SkillCur += dir
	if m.Skills.SkillCur < 0 {
		m.Skills.SkillCur = len(m.Skills.Skills) - 1
	}
	if m.Skills.SkillCur >= len(m.Skills.Skills) {
		m.Skills.SkillCur = 0
	}
	m.Skills.FileCur = 0
	m.Skills.Content = ""
	m.Skills.ContentPath = ""
}

func (m *Model) moveSkillsFile(dir int) {
	flat := m.skillsFlattened()
	if len(flat) == 0 {
		return
	}
	m.Skills.FileCur += dir
	if m.Skills.FileCur < 0 {
		m.Skills.FileCur = len(flat) - 1
	}
	if m.Skills.FileCur >= len(flat) {
		m.Skills.FileCur = 0
	}
	// 光标移到文件即自动加载内容；目录则清空内容区
	if fn := m.currentFlatNode(); fn != nil {
		if fn.IsDir {
			m.Skills.Content = ""
			m.Skills.ContentPath = ""
			m.Skills.ContentScroll = 0
		} else {
			m.loadSkillContent(fn.Path)
		}
	}
}

// --- Workspace 按键 ---

func (m *Model) handleWorkspaceKey(s string) (*Model, tea.Cmd) {
	switch s {
	case "left", "h":
		if m.wsFocus > 0 {
			m.wsFocus = 0
		}
	case "right", "l":
		if m.wsFocus < 1 {
			m.wsFocus = 1
		}
	case "tab", "shift+tab":
		m.wsFocus = (m.wsFocus + 1) % 2
	case "up", "k":
		if m.wsFocus == 0 {
			m.moveGroupCursor(-1)
		} else {
			m.moveCursor(-1)
		}
	case "down", "j":
		if m.wsFocus == 0 {
			m.moveGroupCursor(1)
		} else {
			m.moveCursor(1)
		}
	case "enter":
		if m.inputBuf != "" {
			return m.launchByInput()
		}
		if m.wsFocus == 0 {
			if m.wsTabCur == len(Groups) {
				m.activeGroup = len(Groups)
				m.resetCursor()
				return m, m.onTabSwitch()
			}
			if m.wsTabCur == len(Groups)+1 {
				m.activeGroup = len(Groups) + 1
				m.resetCursor()
				return m, m.onSkillsTabSwitch()
			}
			m.activeGroup = m.wsTabCur
			m.wsFocus = 1
		} else {
			return m.launchSelected()
		}
	default:
		if len(s) == 1 && s[0] >= '0' && s[0] <= '9' && len(m.inputBuf) < 4 {
			m.inputBuf += s
		}
	}
	return m, nil
}

func (m *Model) resetCursor() {
	m.cursor = 0
	m.inputBuf = ""
}

func (m *Model) moveGroupCursor(dir int) {
	total := len(Groups) + 2 // 含历史对话入口和技能入口
	m.wsTabCur = (m.wsTabCur + dir + total) % total
	if m.wsTabCur < len(Groups) {
		m.activeGroup = m.wsTabCur
	}
	m.resetCursor()
}

// --- HISTORY 按键 ---

func (m *Model) handleHistoryKey(s string) (*Model, tea.Cmd) {
	if m.forkMode {
		return m.handleForkInput(s)
	}
	if m.editTitleMode {
		return m.handleEditTitleInput(s)
	}

	switch s {
	case "up", "k":
		if m.history.FocusPanel == 0 {
			m.moveHistoryDir(-1)
		} else {
			m.moveHistorySess(-1)
		}
	case "down", "j":
		if m.history.FocusPanel == 0 {
			m.moveHistoryDir(1)
		} else {
			m.moveHistorySess(1)
		}
	case "tab", "right", "l":
		if m.history.FocusPanel < 1 {
			m.history.FocusPanel = 1
		}
	case "shift+tab", "left", "h":
		if m.history.FocusPanel > 0 {
			m.history.FocusPanel = 0
		}
	case "enter":
		if m.history.FocusPanel == 0 {
			if m.history.DirCursor == len(m.history.Projects)+2 {
				m.activeGroup = 0
				m.resetCursor()
				m.wsTabCur = 0
				m.wsFocus = 1
			}
			m.history.FocusPanel = 1
		} else {
			return m.resumeSelected()
		}
	case "n":
		return m.newSessionFromHistory()
	case "r", "f5":
		if cmd := m.onTabSwitch(); cmd != nil {
			return m, cmd
		}
	case "f":
		m.toggleFavorite()
	case "e", "E":
		if m.currentSession() != nil && !m.forkMode {
			s := m.currentSession()
			m.editTitleMode = true
			m.editTitleBuf = s.DisplayTitle()
			m.editTitleCursor = len([]rune(m.editTitleBuf))
			m.history.FocusPanel = 1
		}
	case "c":
		if m.currentSession() != nil && m.history.FocusPanel == 1 {
			m.forkMode = true
			m.forkBuf = ""
		}
	}
	return m, nil
}

func (m *Model) handleEditTitleInput(s string) (*Model, tea.Cmd) {
	switch s {
	case "enter":
		return m.confirmEditTitle()
	case "esc":
		m.editTitleMode = false
		m.editTitleBuf = ""
		m.editTitleCursor = 0
	case "backspace":
		m.backspaceTitle()
	case "delete":
		m.deleteTitleChar()
	case "left", "h":
		if m.editTitleCursor > 0 {
			m.editTitleCursor--
		}
	case "right", "l":
		r := []rune(m.editTitleBuf)
		if m.editTitleCursor < len(r) {
			m.editTitleCursor++
		}
	case "home", "ctrl+a":
		m.editTitleCursor = 0
	case "end", "ctrl+e":
		m.editTitleCursor = len([]rune(m.editTitleBuf))
	case "space":
		m.insertTitleRune(' ')
	default:
		switch s {
		case "up", "down", "tab", "shift+tab":
		default:
			if len(s) == 1 && s[0] >= 32 {
				m.insertTitleRune(rune(s[0]))
			} else if len(s) > 1 {
				m.insertTitleString(s)
			}
		}
	}
	return m, nil
}

func (m *Model) insertTitleRune(r rune) {
	buf := []rune(m.editTitleBuf)
	pos := m.editTitleCursor
	if pos > len(buf) {
		pos = len(buf)
	}
	buf = append(buf[:pos], append([]rune{r}, buf[pos:]...)...)
	m.editTitleBuf = string(buf)
	m.editTitleCursor = pos + 1
}

func (m *Model) insertTitleString(s string) {
	buf := []rune(m.editTitleBuf)
	pos := m.editTitleCursor
	if pos > len(buf) {
		pos = len(buf)
	}
	ins := []rune(s)
	buf = append(buf[:pos], append(ins, buf[pos:]...)...)
	m.editTitleBuf = string(buf)
	m.editTitleCursor = pos + len(ins)
}

func (m *Model) backspaceTitle() {
	buf := []rune(m.editTitleBuf)
	if m.editTitleCursor > 0 && len(buf) > 0 {
		pos := m.editTitleCursor - 1
		if pos > len(buf) {
			pos = len(buf) - 1
		}
		buf = append(buf[:pos], buf[pos+1:]...)
		m.editTitleBuf = string(buf)
		m.editTitleCursor--
	}
}

func (m *Model) deleteTitleChar() {
	buf := []rune(m.editTitleBuf)
	pos := m.editTitleCursor
	if len(buf) > 0 && pos < len(buf) {
		buf = append(buf[:pos], buf[pos+1:]...)
		m.editTitleBuf = string(buf)
	}
}

func (m *Model) handleForkInput(s string) (*Model, tea.Cmd) {
	switch s {
	case "enter":
		return m.executeFork()
	case "esc":
		m.forkMode = false
		m.forkBuf = ""
	case "backspace":
		if len(m.forkBuf) > 0 {
			m.forkBuf = m.forkBuf[:len(m.forkBuf)-1]
		}
	default:
		if len(s) == 1 && s[0] >= 32 && s[0] < 127 {
			m.forkBuf += s
		} else if len(s) > 1 {
			m.forkBuf += s
		}
	}
	return m, nil
}

// --- 光标移动 ---

func (m *Model) moveHistoryDir(dir int) {
	if len(m.history.Projects) == 0 {
		return
	}
	m.history.DirCursor += dir
	maxDir := len(m.history.Projects) + 3
	if m.history.DirCursor < 0 {
		m.history.DirCursor = maxDir - 1
	}
	if m.history.DirCursor >= maxDir {
		m.history.DirCursor = 0
	}
	m.history.SessCursor = 0
}

func (m *Model) moveHistorySess(dir int) {
	sessions := m.currentSessions()
	if len(sessions) == 0 {
		return
	}
	m.history.SessCursor += dir
	if m.history.SessCursor < 0 {
		m.history.SessCursor = len(sessions) - 1
	}
	if m.history.SessCursor >= len(sessions) {
		m.history.SessCursor = 0
	}
}

func (m *Model) currentSessions() []*Session {
	if m.history.DirCursor == 0 {
		if m.allSessionsDirty || m.allSessionsCache == nil {
			total := 0
			for _, pd := range m.history.Projects {
				total += len(pd.Sessions)
			}
			all := make([]*Session, 0, total)
			for _, pd := range m.history.Projects {
				all = append(all, pd.Sessions...)
			}
			m.allSessionsCache = all
			m.allSessionsDirty = false
		}
		return m.allSessionsCache
	}
	if m.history.DirCursor == 1 {
		return collectFavorites(m.history.Projects, m.history.Favorites)
	}
	idx := m.history.DirCursor - 2
	if idx >= len(m.history.Projects) {
		return nil
	}
	return m.history.Projects[idx].Sessions
}

func (m *Model) currentSession() *Session {
	sessions := m.currentSessions()
	if len(sessions) == 0 {
		return nil
	}
	if m.history.SessCursor >= len(sessions) {
		m.history.SessCursor = len(sessions) - 1
	}
	return sessions[m.history.SessCursor]
}

func (m *Model) currentDirCwd() string {
	if m.history.DirCursor <= 1 {
		return ""
	}
	idx := m.history.DirCursor - 2
	if idx >= len(m.history.Projects) {
		return ""
	}
	return m.history.Projects[idx].Dir
}

func (m *Model) moveCursor(dir int) {
	svcs := WorkspacesByGroup(Groups[m.activeGroup].Label)
	if len(svcs) == 0 {
		return
	}
	m.cursor += dir
	if m.cursor < 0 {
		m.cursor = len(svcs) - 1
	}
	if m.cursor >= len(svcs) {
		m.cursor = 0
	}
}

func (m *Model) toggleMultiSelect() {
	svcs := WorkspacesByGroup(Groups[m.activeGroup].Label)
	if m.cursor < len(svcs) {
		idx := svcs[m.cursor].Index
		if m.selected[idx] {
			delete(m.selected, idx)
		} else {
			m.selected[idx] = true
		}
	}
}