#!/usr/bin/env python
# -*- coding: utf-8 -*-

import getopt
import sys
import search

def show_book_or_person(ids, commit_format=False, tmp_file=False):
    pass

# def search_book():
#     pass

def search_person():
    pass

def commit(filename=None):
    pass

def edit_book_or_person(ids):
    filename = show_book_or_person(ids, commit_format=True, tmp_file=True)
#    run_editor(filename)
    commit(filename)

commands = { 'show':
             { 'args': [('ids', (1,None))],
               'options': ['commit_format', 'tmp_file'],
               'fun': show_book_or_person },
             'search':
             { 'args': [('search_strings', (1,None))],
               'options': ['search_description'],
               'fun': search.search_book_cmd },
             'search-person':
             { 'args': [('search_strings', (1,None))],
               'options': [],
               'fun': search_person },
             'commit':
             { 'args': [('filename', (0,1))],
               'options': [],
               'fun': commit },
             'edit':
             { 'args': [('ids', (1,None))],
               'options': [],
               'fun': edit_book_or_person }
             }

flags = { 'commit_format':
          { 'help': 'output data in the format expected by the commit command' },
          'tmp_file':
          { 'help': 'output data to a new temporary file instead of to stdout' },
          'search_description':
          { 'help': 'include description field when searching' }
        }

general_options = [] # options applicable to all commands

class BadCommandLine(Exception):
    def __init__(self, msg):
        Exception.__init__(self, 'Bad command line: ' + msg)

def check_command_args(args, command):
    cmd_decl = commands[command]
    min_num_args = sum(map(lambda a: a[1][0], cmd_decl['args']))
    unlimited = any(map(lambda a: a[1][1] == None, cmd_decl['args']))
    if not unlimited:
        max_num_args = sum(map(lambda a: a[1][1], cmd_decl['args']))
    if len(args) < min_num_args:
        raise BadCommandLine('Too few arguments for command %s (expects at least %d, %d given).'
                             % (command, min_num_args, len(args)))
    if (not unlimited) and (len(args) < max_num_args):
        raise BadCommandLine('Too many arguments for command %s (expects at most %d, %d given).'
                             % (command, max_num_args, len(args)))

def check_command_opts(opts, command):
    cmd_decl = commands[command]
    for opt,val in opts:
        if ((opt not in cmd_decl['options']) and
            (opt not in general_options)):
            raise BadCommandLine('Option %s not applicable to command %s.'
                                 % (opt, command))

def assign_command_args(args, command):
    cmd_decl = commands[command]
    d = {}
    i = 0
    for param in cmd_decl['args']:
        pname = param[0]
        pmin = param[1][0]
        pmax = param[1][1]
        if pmax == 1:
            if i < len(args):
                d[pname] = args[i]
                i += 1
            else:
                d[pname] = None
        else:
            d[pname] = []
            j = 0
            while i + j < len(args) and (pmax == None or j < pmax):
                d[pname].append(args[i + j])
                j += 1
            i = i + j
    return d

def assign_command_opts(opts, command):
    d = {}
    for option, value in opts:
        if option in flags:
            d[option] = True
        else:
            d[option] = value
    return d

def parse_cmdline(args):
    def getopt_option_name(internal_name):
        return internal_name.replace('_', '-')
    def internal_option_name(getopt_ret_name):
        return getopt_ret_name[2:].replace('-', '_')

    option_names = map(getopt_option_name, flags)

    options, args = getopt.getopt(args, '', option_names)
    
    if len(args) == 0:
        raise BadCommandLine('No command specified.')
    cmd_name = args[0]
    if cmd_name not in commands:
        raise BadCommandLine('Nonexisting command %s.' % cmd_name)
    cmd_decl = commands[cmd_name]
    cmd_args = args[1:]
    cmd_opts = map(lambda (opt,val): (internal_option_name(opt), val),
                   options)

    check_command_args(cmd_args, cmd_name)
    check_command_opts(cmd_opts, cmd_name)

    return { 'command': cmd_name,
             'args': combine_dicts(assign_command_args(cmd_args, cmd_name),
                                   assign_command_opts(cmd_opts, cmd_name)) }

def invoke_command(command, args):
    cmd_decl = commands[command]
    cmd_decl['fun'](**args)

def combine_dicts(*dicts):
    res = {}
    for d in dicts:
        res.update(d)
    return res


cmdline_parsed = parse_cmdline(sys.argv[1:])
print 'command line parsed to:', cmdline_parsed
invoke_command(cmdline_parsed['command'],
               cmdline_parsed['args'])