TUI

lib/bbs/flow.rb

@@ -118,6 +118,10 @@ module BBS
     def output(&block)
       @steps << { type: :output, block: block }
     end
+
+    def tui(definition)
+      @steps << { type: :tui, definition: definition }
+    end
   end
 
   class MenuBuilder

lib/bbs/flow_runner.rb

@@ -70,6 +70,7 @@ module BBS
       when :pick          then run_pick(step)
       when :body          then run_body(step)
       when :output        then run_output(step)
+      when :tui           then run_tui(step)
       end
     end
 
@@ -341,6 +342,13 @@ module BBS
       nil
     end
 
+    def run_tui(step)
+      TUIRunner.new(@session, @session_id, step[:definition]).run
+      nil
+    rescue IOError, Errno::EPIPE, Errno::ECONNRESET
+      :halt
+    end
+
     # ── helpers ────────────────────────────────────────────────────────────────
 
     def strip_md(text)

lib/bbs/telnet.rb

@@ -19,6 +19,27 @@ module BBS
       send_raw [IAC, DO,   SGA_OPT].pack('C*')
     end
 
+    def readkey
+      loop do
+        raw  = @client.read(1)
+        return nil if raw.nil?
+        byte = raw.ord
+
+        if byte == IAC
+          absorb_iac
+          next
+        end
+
+        case byte
+        when 13, 10  then return :enter
+        when 27      then return read_escape_sequence
+        when 8, 127  then return :backspace
+        when 3       then return :interrupt
+        when 32..126 then return raw
+        end
+      end
+    end
+
     def readline
       line    = +""
       last_cr = false
@@ -70,6 +91,22 @@ module BBS
 
     private
 
+    def read_escape_sequence
+      b1 = @client.read(1)
+      return :escape if b1.nil? || b1 != '['
+
+      b2 = @client.read(1)
+      return :escape if b2.nil?
+
+      case b2
+      when 'A' then :up
+      when 'B' then :down
+      when 'C' then :right
+      when 'D' then :left
+      else          :escape
+      end
+    end
+
     def absorb_iac
       cmd = @client.read(1)
       return if cmd.nil?

lib/bbs/tui.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+module BBS
+  class TUI
+    attr_reader :init_block, :render_block, :key_bindings
+
+    def self.define(&block)
+      tui = new
+      tui.instance_eval(&block)
+      tui.freeze
+    end
+
+    def initialize
+      @key_bindings = {}
+    end
+
+    def init(&block)
+      @init_block = block
+    end
+
+    def render(&block)
+      @render_block = block
+    end
+
+    def key(k, action = nil, &block)
+      @key_bindings[k] = action || block
+    end
+  end
+end

lib/bbs/tui_runner.rb

@@ -0,0 +1,103 @@
+# frozen_string_literal: true
+
+module BBS
+  class TUIRunner
+    def initialize(session, session_id, tui)
+      @session    = session
+      @session_id = session_id
+      @tui        = tui
+    end
+
+    def run
+      ctx = Context.new(@session, @session_id)
+      ctx.instance_eval(&@tui.init_block) if @tui.init_block
+
+      loop do
+        ctx.do_render(@tui.render_block) if @tui.render_block
+
+        key = @session.readkey
+        break if key.nil?
+
+        handler = @tui.key_bindings[key]
+        next unless handler
+
+        result = handler.is_a?(Symbol) ? handler : ctx.instance_eval(&handler)
+        break if result == :halt
+      end
+    rescue IOError, Errno::EPIPE, Errno::ECONNRESET
+      nil
+    ensure
+      @session.write("\e[?25h\e[2J\e[H")
+    end
+
+    class Context
+      STYLES = FlowRunner::STYLES
+
+      def initialize(session, session_id)
+        @session    = session
+        @session_id = session_id
+        @buf        = +""
+      end
+
+      def do_render(block)
+        @buf = +"\e[?25l"
+        instance_eval(&block)
+        @buf << "\e[?25h"
+        @session.write(@buf)
+      end
+
+      # ── drawing primitives ────────────────────────────────────────────────
+
+      def clear
+        @buf << "\e[2J\e[H"
+      end
+
+      def at(col, row)
+        @buf << "\e[#{row};#{col}H"
+      end
+
+      def text(content, x: nil, y: nil, style: nil)
+        at(x, y) if x && y
+        color = STYLES[style]
+        @buf << (color ? "#{color}#{content}\e[0m" : content.to_s)
+      end
+
+      def bar(y:, content:, width: 80, style: :muted)
+        text content.to_s.ljust(width), x: 1, y: y, style: style
+      end
+
+      def list(items, x:, y:, selected: nil, style: :muted, highlight: :success)
+        norm = STYLES.fetch(style, STYLES[:muted])
+        hi   = STYLES.fetch(highlight, STYLES[:success])
+        items.each_with_index do |item, i|
+          at x, y + i
+          @buf << (i == selected ? "#{hi}▶ #{item}\e[0m" : "#{norm}  #{item}\e[0m")
+        end
+      end
+
+      def box(x:, y:, w:, h:, title: nil, style: :muted)
+        color = STYLES.fetch(style, STYLES[:muted])
+        inner = w - 2
+
+        at x, y
+        if title
+          prefix = "══ #{title} "
+          fill   = [inner - prefix.length, 0].max
+          @buf << "#{color}╔#{prefix}#{'═' * fill}╗\e[0m"
+        else
+          @buf << "#{color}╔#{'═' * inner}╗\e[0m"
+        end
+
+        (1...h - 1).each do |dy|
+          at x, y + dy
+          @buf << "#{color}║\e[0m#{' ' * inner}#{color}║\e[0m"
+        end
+
+        at x, y + h - 1
+        @buf << "#{color}╚#{'═' * inner}╝\e[0m"
+
+        yield x + 1, y + 1, inner, h - 2 if block_given?
+      end
+    end
+  end
+end