#!/usr/bin/env ruby

$us = File.basename $0

require 'getoptlong'
require 'fileutils'
require 'json'

# ----------------------------------------------------------------
# This is used to run live code for Miller Sphinx docs.
# * Edit foo.rst.in
# * Run this script to generate foo.rst
# * The caller should chmod 400 the foo.rst file
# * See README.md for more information.

def main
  input_handle = $stdin
  output_handle = $stdout

  output_handle.puts("..")
  output_handle.puts("    PLEASE DO NOT EDIT DIRECTLY. EDIT THE .rst.in FILE PLEASE.")
  output_handle.puts("")

  input_handle.readlines.each do |content_line|

    if content_line =~ /POKI_INCLUDE_ESCAPED\(([^)]+)\)HERE/
      included_file_name = $1
      include_escaped(included_file_name, output_handle)

    elsif content_line =~ /POKI_INCLUDE_AND_RUN_ESCAPED\(([^)]+)\)HERE/
      included_file_name = $1
      cmd = File.readlines(included_file_name).join('')
      run_command(cmd, output_handle)

    elsif content_line =~ /POKI_RUN_CONTENT_GENERATOR\(([^)]+)\)HERE/
      cmd = $1
      run_content_generator(cmd, output_handle)

    elsif content_line =~ /POKI_RUN_COMMAND{{(.+)}}HERE/
       cmd = $1
       run_command(cmd, output_handle)

    elsif content_line =~ /POKI_RUN_COMMAND_TOLERATING_ERROR{{(.+)}}HERE/
      cmd = $1
      run_command_tolerating_error(cmd, output_handle)

    elsif content_line =~ /POKI/
      #raise "Unhandled poki line #{content_line}"
      $stderr.puts "Unhandled poki line <<#{content_line}>>"
      output_handle.write(content_line)
    else
      output_handle.write(content_line)
    end
  end
end

# ----------------------------------------------------------------
def include_escaped(included_file_name, output_handle)
  write_card(false, File.readlines(included_file_name), output_handle)
end

# ----------------------------------------------------------------
def run_command(cmd, output_handle)
  cmd_output = `#{cmd} 2>&1`
  status = $?.to_i
  if status != 0
    raise "\"#{cmd}\" exited with non-zero code #{status}."
  end
  # The command can be multi-line
  cmd_lines = cmd.split(/\n/)
  write_card(true, cmd_lines + cmd_output.split(/\n/), output_handle)
end

# ----------------------------------------------------------------
def run_command_tolerating_error(cmd, output_handle)
  cmd_output = `#{cmd} 2>&1`
  write_card(true, [cmd] + cmd_output.split(/\n/), output_handle)
end

# ----------------------------------------------------------------
def run_content_generator(cmd, output_handle)
  cmd_output = `#{cmd} 2>&1`
  status = $?.to_i
  if status != 0
    raise "\"#{cmd}\" exited with non-zero code #{status}."
  end
  output_handle.puts(cmd_output)
end

# ----------------------------------------------------------------
def write_card(highlight_first_line, content_lines, output_handle)
  output_handle.puts('.. code-block:: none')
  if highlight_first_line
    output_handle.puts('   :emphasize-lines: 1,1') # 'hll' in _static/*.css
  end
  output_handle.puts
  content_lines.each do |content_line|
    # The callsite should do the "::", blank line, then this, then blank line
    # in order to adhere to Sphinx code-block syntax. (Another option would be
    # us here doing the ::, blank line, , then the content line, then the other
    # blank line.)
    output_handle.write('    ') # four leading spaces for Sphinx, on each line
    output_handle.puts(content_line)
  end
end

# ================================================================
main()