package tui

import (
	"os"
	"os/exec"
	"regexp"
	"strings"
	"time"

	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/lipgloss"
)

var dangerousPatterns = []*regexp.Regexp{
	regexp.MustCompile(`(?i)\brm\s+(-[a-zA-Z]*f[a-zA-Z]*\s+|/)`),
	regexp.MustCompile(`(?i)\bmkfs\b`),
	regexp.MustCompile(`(?i)\bdd\s+if=`),
	regexp.MustCompile(`(?i)\b(format\s+[A-Za-z]:)\b`),
	regexp.MustCompile(`(?i):\(\)\{.*\}`),
	regexp.MustCompile(`(?i)>(/dev/|/etc/|/boot/)`),
	regexp.MustCompile(`(?i)\bshutdown\b`),
	regexp.MustCompile(`(?i)\breboot\b`),
	regexp.MustCompile(`(?i)\bhalt\b`),
	regexp.MustCompile(`(?i)\bpoweroff\b`),
}

func isDangerousCommand(input string) bool {
	for _, pat := range dangerousPatterns {
		if pat.MatchString(input) {
			return true
		}
	}
	return false
}

func (m Model) renderShell() string {
	if m.termAIShow {
		aiWidth := 36
		termWidth := m.width - aiWidth - 2
		if termWidth < 20 {
			termWidth = 20
			aiWidth = m.width - termWidth - 2
		}

		termPanel := m.renderTermPanel(termWidth)
		aiPanel := m.renderAIPanel(aiWidth)

		return lipgloss.JoinHorizontal(lipgloss.Top, termPanel, aiPanel)
	}

	return m.renderTermPanel(m.width)
}

func (m Model) renderTermPanel(width int) string {
	var b strings.Builder

	cwdStyle := lipgloss.NewStyle().Foreground(dimColor).Render(m.termCwd)
	b.WriteString(renderSectionWithIcon("Terminal", "▶"))
	b.WriteString("  ")
	b.WriteString(cwdStyle)
	b.WriteString("\n\n")

	sep := lipgloss.NewStyle().Foreground(borderColor).Render(strings.Repeat("─", max(width-4, 10)))
	b.WriteString(" " + sep)
	b.WriteString("\n")

	for _, line := range m.termLog {
		b.WriteString(line + "\n")
	}

	return b.String()
}

func (m Model) renderAIPanel(width int) string {
	var b strings.Builder

	b.WriteString(renderSectionWithIcon("AI Assistant", "◈"))
	b.WriteString("\n\n")

	sep := lipgloss.NewStyle().Foreground(borderColor).Render(strings.Repeat("─", max(width-4, 10)))
	b.WriteString(" " + sep)
	b.WriteString("\n\n")

	for _, msg := range m.termAIChat {
		b.WriteString(msg)
		b.WriteString("\n\n")
	}

	if m.termAILoading {
		b.WriteString(lipgloss.NewStyle().Foreground(warmColor).Render(" " + getAnimFrame(m.animationFrame) + " thinking..."))
		b.WriteString("\n")
	}

	inputLabel := lipgloss.NewStyle().Foreground(roseColor).Render("⟩ ")
	b.WriteString(inputLabel)
	b.WriteString(m.termAIInput)

	return lipgloss.NewStyle().
		Background(bgPanel).
		Border(lipgloss.Border{Left: "│"}).
		BorderForeground(borderColor).
		Width(width).
		Padding(0, 1).
		Render(b.String())
}

func (m Model) handleShellKey(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
	switch msg.String() {
	case "ctrl+c":
		if m.termCmd != nil && m.termCmd.Process != nil {
			m.termCmd.Process.Kill()
			m.termRunning = false
			m.termLog = append(m.termLog, lipgloss.NewStyle().Foreground(errorColor).Render("^C"))
			m.termCmd = nil
			m.viewport.SetContent(m.renderContent())
			return m, nil
		}
		now := time.Now()
		if m.ctrlCCount > 0 && now.Sub(m.lastCtrlC) < 2*time.Second {
			return m, tea.Quit
		}
		m.ctrlCCount++
		m.lastCtrlC = now
		m.showingQuit = true
		m.confirmCursor = 1
		m.viewport.SetContent(m.renderContent())
		return m, nil
	case "ctrl+t":
		m.showingTabMenu = true
		m.tabMenuCursor = int(m.activeTab)
		return m, nil
	case "ctrl+a":
		m.termAIShow = !m.termAIShow
		m.viewport.SetContent(m.renderContent())
		return m, nil
	case "enter":
		if m.termRunning {
			return m, nil
		}
		input := strings.TrimSpace(m.termInput)
		m.termInput = ""
		if input == "" {
			return m, nil
		}
		if input == "exit" || input == "quit" {
			return m, nil
		}
		if input == "clear" {
			m.termLog = nil
			m.viewport.SetContent(m.renderContent())
			return m, nil
		}
		if isDangerousCommand(input) {
			m.termLog = append(m.termLog, errMsgStyle.Render(" blocked: potentially dangerous command"))
			m.viewport.SetContent(m.renderContent())
			m.viewport.GotoBottom()
			return m, nil
		}
		if strings.HasPrefix(input, "cd ") {
			dir := strings.TrimPrefix(input, "cd ")
			dir = strings.TrimSpace(dir)
			if dir == "~" {
				home, _ := os.UserHomeDir()
				dir = home
			}
			if err := os.Chdir(dir); err == nil {
				m.termCwd, _ = os.Getwd()
				m.termLog = append(m.termLog, lipgloss.NewStyle().Foreground(dimColor).Render(m.termCwd+" $ "+input))
			} else {
				m.termLog = append(m.termLog, errMsgStyle.Render(" cd: "+err.Error()))
			}
			m.viewport.SetContent(m.renderContent())
			m.viewport.GotoBottom()
			return m, nil
		}
		m.termLog = append(m.termLog, lipgloss.NewStyle().Foreground(dimColor).Render(m.termCwd+" $ ")+input)
		m.viewport.SetContent(m.renderContent())
		m.viewport.GotoBottom()
		return m, m.runTermCommand(input)
	case "backspace":
		if len(m.termInput) > 0 {
			m.termInput = m.termInput[:len(m.termInput)-1]
			m.viewport.SetContent(m.renderContent())
		}
		return m, nil
	default:
		if len(msg.String()) == 1 {
			m.termInput += msg.String()
			m.viewport.SetContent(m.renderContent())
		}
	}
	return m, nil
}

func (m Model) runTermCommand(input string) tea.Cmd {
	return tea.Cmd(func() tea.Msg {
		shell := os.Getenv("SHELL")
		if shell == "" {
			shell = "/bin/sh"
		}
		cmd := exec.Command(shell, "-c", input)
		cmd.Dir = m.termCwd
		out, err := cmd.CombinedOutput()
		if err != nil {
			return termOutputMsg{line: string(out) + errMsgStyle.Render(err.Error())}
		}
		return termOutputMsg{line: string(out)}
	})
}