#!/usr/bin/env python
#  -*- coding: iso-8859-1 -*-

###
# Command line tool to manage SALOME configuration.
# Usage: type "scfg help" to learn how to use tool.
###

import sys
import os
from sconfig.salome_config import CfgTool, defaultConfFile

###
# TODO
# 1. Improve parsing of command line: each command should be defined as:
#    - command:    name of the command
#    - help:       help string as appears in the short description of a command in a list
#                  of commands and as a first line of command's help
#    - options:    (dict) see below
#    - parameters: (list or dict) see below
#    Each option should be defined with:
#    - title:      one letter signature
#    - help:       help string
#    - parameter:  name of parameter if option requires a parameter
#    Each parameter should be defined with:
#    - title:      as appears in help information
#    - optional:   flag (boolean) showing if this parameter is optional
#    - help:       help description
#    
#    Parser of command line should then automatically check validity of the command,
#    its parameters and options.
#  
# 2. Usage and help information should be automaticall generated and formatted
#    from command description as described above.
# 
# 3. Protect from adding same named option to a command.
# 
# 4. Improve formatting help for command's parameters (see 1) - namely, wrapping
#    into a block.
###

##
# function: get_tool_name
# 
# gets a name of this command line tool (string)
##

def get_tool_name():
    return os.path.basename(sys.argv[0])

##
# function: verbose
# 
# returns True when in debug mode (env var VERBOSE is set to 1)
##

def verbose():
    return bool(os.getenv("VERBOSE", False))

##
# function: debug
# 
# prints debug information (for debug purposes)
#
# Parameters:
#   args: output data to be printed to the screen (any printable objects)
##

def debug(*args):
    if verbose():
        print("[DEBUG]", end=' ')
        for a in args: print(a, end=' ')
        print()
    pass

##
# function: error_exit
# 
# prints error information and exits with non-zero status
# 
# Parameters:
#   msg: error message (string)
##

def error_exit(msg):
    print("%s: %s" % (get_tool_name(), msg))
    sys.exit(1)
    pass

##
# function: get_commands
# 
# get supported commands
# 
# return value is a dictionary:
# { cmd : ( help, opt_map ) }
# here:
# - cmd is a command (string)
# - help is a command's general help information on a command (string)
# - opt_map is a disctionary of allowed command's options:
#   { opt: opt_help }, where 
#   - opt is option ("a:" if option requires a parameter or just "a" elsewhere, where
#                    "a" is any letter)
#   - opt_help is a help information on the option (string).
# 
# See also: add_command
##

def get_commands():
    if not globals().get("__commands__"): globals()["__commands__"] = {}
    return globals().get("__commands__")

##
# function: add_command
# 
# adds command to the tool
#
# Parameters:
#   cmd: command (string)
#   help_string: help information on the command (string)
#   options: options supported by the command (map {opt: opt_help}, see get_commands)
##

def add_command(cmd, help_string, options):
    if cmd in get_commands():
        debug("command %s already exists" % cmd)
    else:
        get_commands()[ cmd ] = ( help_string, options )
    pass

##
# function: get_opts
# 
# gets supported options for the command
# 
# Parameters:
#   cmd: command (string)
# 
# return value is map {opt: opt_help} (see get_commands)
##

def get_opts(cmd):
    if cmd is None: cmd = ""
    opts = {}
    try:
        opts = get_commands()[cmd][1]
    except:
        pass
    return opts

##
# function: get_help
# 
# gets help string for the command
# 
# Parameters:
#   cmd: command (string)
# 
# return value is unformatted string
##

def get_help(cmd):
    if cmd is None: cmd = ""
    help_string = ""
    try:
        help_string = get_commands()[cmd][0]
    except:
        pass
    return help_string

##
# function: format_string
# 
# formats string into block according to the given block width
# 
# Parameters:
#   s: string data
#   width: requested width of resulting string block
# 
# return formatted string block
##

def format_string(s, width):
    blocks = s.split("\n")
    result = []
    for block in blocks:
        block = block.replace("\t", " [[TAB]] ")
        words = block.split()
        current_string = ""
        for word in words:
            word = word if word != "[[TAB]]" else " "*2
            if not current_string:
                current_string = word
            else:
                if len(current_string + " " + word) <= width:
                    current_string += " " + word
                else:
                    result.append(current_string)
                    current_string = word
                    pass
                pass
            pass
        result.append(current_string)
        pass
    return "\n".join(result)

##
# function: format_commands
# 
# formats short help on all supported commands
# 
# return string that contains formatted help on commands
##

def format_commands():
    commands = get_commands()
    # filter out tool itself
    commands = sorted([a for a in commands if a != ""])
    # sort commands alphabetically
    # get max command's length
    max_length = max([ len(i) for i in commands])
    # generate formatting string
    prefix = "  "
    separator = "    "
    fmt_string = prefix + "%" + "-%ds" % max_length + separator
    def _format(_c):
        _h = get_help(_c).split("\n")[0]
        _h = format_string(_h, 80-(max_length+len(prefix)+len(separator)))
        _h = _h.split("\n")
        _t = prefix + " " * max_length + separator
        _r = []
        _r.append(_h[0])
        for _i in _h[1:]: _r.append(_t + _i)
        return "\n".join(_r)
    return "\n".join([ fmt_string % i + _format(i) for i in commands])

##
# function: format_list_options
# 
# formats short help on commands's options to be inserted into short help info on a command
# 
# Parameters:
#   cmd: command (string)
# 
# return string that contains formatted help
##

def format_list_options(cmd):
    opts = get_opts(cmd)
    return "".join([" [%s]" % i for i in opts])

##
# function: format_options
# 
# formats help on commands's options to be inserted after short help info on a command
# 
# Parameters:
#   cmd: command (string)
# 
# return string that contains formatted help
##

def format_options(cmd):
    opts = get_opts(cmd)
    opts_names = list(opts.keys())
    if not opts: return ""
    # get max command's length
    max_length = max([ len(i) for i in opts_names])
    # generate formatting string
    prefix = "  "
    separator = "    "
    fmt_string = prefix + "%" + "-%ds" % max_length + separator
    def _format(_o):
        _h = opts[_o]
        _h = format_string(_h, 80-(max_length+len(prefix)+len(separator)))
        _h = _h.split("\n")
        _t = prefix + " " * max_length + separator
        _r = []
        _r.append(_h[0])
        for _i in _h[1:]: _r.append(_t + _i)
        return "\n".join(_r)
    return "\n" + "\n".join([ fmt_string % i + _format(i) for i in opts_names]) + "\n"

##
# function: usage
# 
# prints help and exits with zero status
#
# Parameters:
#   cmd: command (string)
##

def usage(cmd=None):
    if cmd is None: cmd = ""
    if cmd not in get_commands(): error_exit("unknown command: %s" % cmd)
    fmt = {}
    fmt[ "prg" ] = get_tool_name()
    fmt[ "cmd" ] = get_tool_name() if not cmd else cmd
    fmt[ "cmd_list" ] = format_commands()
    fmt[ "opts" ] = format_list_options(cmd)
    fmt[ "opt_list" ] = format_options(cmd)
    help_string = get_help(cmd)
    help_string = help_string.replace("\t", "  ")
    print(help_string.format(**fmt))
    sys.exit(0)
    pass

##
# function: parse_cmd_line
# 
# parses command line; prints error and exits if unsupported command
# or option is specified
# 
# Parameters:
#   args: arguments being parsed (list of strings)
##

def parse_cmd_line(args):
    tool_opts, cmd, cmd_opts, tgt, params = {}, None, {}, None, []
    args.reverse()
    commands = get_commands()
    while args:
        a = args.pop()
        if a == "-":
            # empty option
            error_exit("empty option is not allowed")
        if a.startswith("-"):
            allowed_opts = list(get_opts(cmd).keys())
            allowed_opts = dict([(i[1], len(i)>2) for i in allowed_opts])
            processed_opts = tool_opts if cmd is None else cmd_opts
            cmd_descr = "" if cmd is None else " for command '%s'" % cmd
            opts = a[1:]
            while opts:
                o = opts[0]
                opts = opts[1:]
                if o == "-":
                    # "--" format is not supported
                    error_exit("invalid format of option")
                elif o in allowed_opts:
                    if allowed_opts[o]:
                        # supported option; requires parameter
                        if opts:
                            processed_opts[ o ] = opts
                            opts = []
                        elif args and not args[-1].startswith("-") and not args[-1] in commands:
                            processed_opts[ o ] = args.pop()
                        else:
                            error_exit("option %s%s requires argument" % (o, cmd_descr))
                    else:
                        # supported option; does not require parameter
                        processed_opts[ o ] = None
                        pass
                    pass
                else:
                    # unsupported option
                    error_exit("unknown option: -%s%s" % (o, cmd_descr))
                pass # while opts
            pass
        elif not cmd:
            cmd = a
            if cmd not in commands:
                # unsupported command
                error_exit("unknown command: %s" % cmd)
            pass
        elif not tgt:
            tgt = a
            pass
        else:
            params += [ a ]
    return tool_opts, cmd, cmd_opts, tgt, params

##
# function: main
# 
# main entry point of the tool
##

def main():
    # set-up commands

    # - tool itself
    help_string  = "Command line tool to manage SALOME configuration.\n\n"
    help_string += "Usage: {prg}{opts} COMMAND [ARGS]\n"
    help_string += "{opt_list}\n"
    help_string += "Supported commands:\n"
    help_string += "{cmd_list}\n\n"
    help_string += "See '{prg} help COMMAND' for more information on a specific command."
    options = {}
    options [ "-s FILE" ] = "Path to the configuration file; default: %s." % defaultConfFile()
    add_command("",
                help_string,
                options)

    # - help command
    help_string  = "Display help information about this tool.\n\n"
    help_string += "Usage: {prg} {cmd}{opts}\n"
    help_string += "{opt_list}"
    add_command("help",
                help_string,
                {})

    # - set command
    help_string  = "Create or modify configuration object.\n\n"
    help_string += "Usage: {prg} {cmd}{opts} TARGET [PARAM VALUE ...]\n\n"
    help_string += "\tTARGET: configuration object being created / modified\n"
    help_string += "\tPARAM: parameter of the target object\n"
    help_string += "\tVALUE: value to be assigned to the attribute of the target object\n"
    help_string += "{opt_list}"
    add_command("set",
                help_string,
                {})

    # - get command
    help_string  = "Get parameter of configuration object.\n\n"
    help_string += "Usage: {prg} {cmd}{opts} TARGET PARAM\n\n"
    help_string += "\tTARGET: configuration object being inspected\n"
    help_string += "\tPARAM: parameter of the target object\n"
    help_string += "{opt_list}"
    add_command("get",
                help_string,
                {})

    # - remove command
    help_string  = "Remove configuration object or its attribute(s).\n\n"
    help_string += "Usage: {prg} {cmd}{opts} TARGET [PARAM ...]\n\n"
    help_string += "\tTARGET: configuration object\n"
    help_string += "\tPARAM: attribute of the target object\n"
    help_string += "{opt_list}"
    add_command("remove",
                help_string,
                {})

    # - dump command
    help_string  = "Dump configuration.\n\n"
    help_string += "Usage: {prg} {cmd}{opts} [TARGET]\n\n"
    help_string += "\tTARGET: optional configuration object (if not specified,\n"
    help_string += "\t        all configuration is dumped).\n"
    help_string += "{opt_list}"
    add_command("dump",
                help_string,
                {})

    # - verify command
    help_string  = "Verify configuration.\n\n"
    help_string += "Usage: {prg} {cmd}{opts} [TARGET]\n\n"
    help_string += "\tTARGET: optional configuration object (if not specified,\n"
    help_string += "\t        all configuration is verified).\n"
    help_string += "{opt_list}"
    add_command("verify",
                help_string,
                {})

    # - clean command
    help_string  = "Clean configuration.\n\n"
    help_string += "Usage: {prg} {cmd}{opts}\n"
    help_string += "{opt_list}"
    add_command("clean",
                help_string,
                {})

    # parse command line

    opts, cmd, cmd_opts, tgt, params = parse_cmd_line(sys.argv[1:])
    debug("parse command line: options =", opts, "; command =", cmd, "; command options =", cmd_opts, "; target =", tgt, "; arguments =", params)

    # process command

    if not cmd or cmd == "help":
        # show help and exit
        usage(tgt)
        pass

    try:
        # check if custom source file is specified
        
        src_file = opts["s"] if "s" in opts else None
        debug("source file:", src_file)
        
        # create config tool

        cfg_tool = CfgTool(src_file)
        debug("cfg tool:", cfg_tool)

        # TODO: we should not check commands in a switch-like block below;
        # instead processing should be done automatically basing on the
        # predefined set of commands (TODO)

        if cmd == "get":
            if not tgt:
                error_exit("%s: target is not specified!" % cmd)
            if len(params) < 1:
                error_exit("%s: parameter of target %s is not specified!" % (cmd, tgt))
            # only one parameter can be read!
            if len(params) > 1:
                error_exit("%s: can't read more than one parameter at once!" % cmd)
            def _toString(v):
                if v is None: return ""
                elif isinstance(v, list): return " ".join(v)
                else: return v
            print(_toString(cfg_tool.get(tgt, params[0])))
            pass
        elif cmd == "set":
            if not tgt:
                error_exit("%s: target is not specified!" % cmd)
            # empty parameters list is allowed!
            cfg_tool.set(tgt, *params)
            pass
        elif cmd == "remove":
            if not tgt:
                error_exit("%s: target is not specified!" % cmd)
            # empty parameters list is allowed!
            cfg_tool.remove(tgt, *params)
            pass
        elif cmd == "dump":
            if len(params) > 0:
                error_exit("%s: command does not support parameters!" % cmd)
            # empty target is allowed!
            cfg_tool.dump(tgt)
            pass
        elif cmd == "verify":
            if len(params) > 0:
                error_exit("%s: command does not support parameters!" % cmd)
            # empty target is allowed!
            errors = []
            if cfg_tool.verify(tgt, errors):
                msg = " (no products found)" if not cfg_tool.get("cfg", "products") else ""
                print("Configuration is valid%s." % msg)
            else:
                raise Exception("Configuration is invalid:\n"+ "\n".join(errors))
            pass
        elif cmd == "clean":
            if tgt:
                error_exit("%s: command does not support target!" % cmd)
            if len(params) > 0:
                error_exit("%s: command does not support parameters!" % cmd)
            # empty target is allowed!
            cfg_tool.clean()
            pass
        else:
            # unknown command: normally we should not go here
            error_exit("unknown command: %s" % cmd)
            pass
        pass
    except Exception as e:
        error_exit(e)
    pass
    
if __name__ == "__main__":
    main()