package internal

import (
	"charm.land/bubbletea/v2"
)

// --- 按键分发 ---

func (m *Model) handleKey(s string) (*Model, tea.Cmd) {
	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
	if s == "1" {
		if m.IsHistoryTab() {
			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 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()
}

// --- 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()
			}
			m.activeGroup = m.wsTabCur
			m.wsFocus = 1
		} else {
			return m.launchSelected()
		}
	default:
		if len(s) == 1 && s[0] >= '0' && s[0] <= '9' {
			m.inputBuf += s
		}
	}
	return m, nil
}

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

func (m *Model) moveGroupCursor(dir int) {
	total := len(Groups) + 1 // 含历史入口
	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)
	}

	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 "c":
		if m.currentSession() != nil && m.history.FocusPanel == 1 {
			m.forkMode = true
			m.forkBuf = ""
		}
	}
	return m, nil
}

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
		}
	}
	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 {
		var all []*Session
		for _, pd := range m.history.Projects {
			all = append(all, pd.Sessions...)
		}
		return all
	}
	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
		}
	}
}