#!/usr/bin/python

# Interactively prompts for variable values
# expected arguments are
# command -d [default-xml [custom-xml [ consolidated-xml ]]]
#
# -d is for the myplc-devel package

# we use 3 instances of PLCConfiguration throughout:
# cdef : models the defaults, from plc_default.xml
# cread : merged from plc_default & configs/site.xml
# cwrite : site.xml + pending changes

import sys
import os
import re
import readline
import getopt

from plc_config import PLCConfiguration

####################
release_id = "$Id: plc-config-tty,v 1.8 2006/08/18 14:34:45 thierry Exp $"
release_rev = "$Revision: 1.8 $"

def init_flavour (flavour):
    global service
    global common_variables
    if (flavour == "devel"):
        service="plc-devel"
        common_variables=("PLC_DEVEL_FEDORA_URL",
                          "PLC_DEVEL_CVSROOT")
        config_dir = "/plc/devel/data/etc/planetlab"
    else:
        service="plc"
        common_variables=("PLC_NAME",
                          "PLC_ROOT_USER",
                          "PLC_ROOT_PASSWORD",
                          "PLC_MAIL_SUPPORT_ADDRESS",
                          "PLC_DB_HOST",
                          "PLC_API_HOST",
                          "PLC_WWW_HOST",
                          "PLC_BOOT_HOST",
                          "PLC_NET_DNS1",
                          "PLC_NET_DNS2")
        config_dir = "/etc/planetlab"
    global def_default_config
    def_default_config= "%s/default_config.xml" % config_dir
    global def_site_config
    def_site_config = "%s/configs/site.xml" % config_dir
    global def_consolidated_config
    def_consolidated_config = "%s/plc_config.xml" % config_dir

    global mainloop_usage
    mainloop_usage= """Available commands:
 Uppercase versions give variables comments, when available
-u/U\t\t\tEdit usual variables
-w\t\t\tWrite & consolidate
-r\t\t\tRestart %s service
-q\t\t\tQuit (without saving)
-h/?\t\t\tThis help
---
l/L [<cat>|<var>]\tShow Locally modified variables/values
-s/S [<cat>|<var>]\tShow variables/values (all, in category, single)
-e/E [<cat>|<var>]\tEdit variables (all, in category, single)
---
-c\t\t\tList categories
-v/V [<cat>|<var>]List Variables (all, in category, single)
---
Typical usage involves: u, [l,] w, r, q
""" % service

def usage ():
    command_usage="Usage: %s [-d] [-v] [default-xml [site-xml [consolidated-xml]]]"% sys.argv[0]
    init_flavour ("boot")
    command_usage +="""
  -v shows version and exits
\t default-xml defaults to %s
\t site-xml defaults to %s
\t consolidated-xml defaults to %s""" % (def_default_config,def_site_config, def_consolidated_config)
    command_usage += """
  Unless you specify the -d option, meaning you want to configure
  myplc-devel instead of regular myplc, in which case""" 
    init_flavour ("devel")
    command_usage +="""
\t default-xml defaults to %s
\t site-xml defaults to %s
\t consolidated-xml defaults to %s""" % (def_default_config,def_site_config, def_consolidated_config)
    print(command_usage)
    sys.exit(1)

####################
variable_usage= """Edit Commands :
#\tShow variable comments
.\tStops prompting, return to mainloop
/\tCleans any site-defined value, reverts to default
=\tShows default value
>\tSkips to next category
?\tThis help
"""

####################
def get_value (config,  category_id, variable_id):
    (category, variable) = config.get (category_id, variable_id)
    return variable['value']

def get_current_value (cread, cwrite, category_id, variable_id):
    # the value stored in cwrite, if present, is the one we want
    try:
        result=get_value (cwrite,category_id,variable_id)
    except:
        result=get_value (cread,category_id,variable_id)
    return result

# refrain from using plc_config's _sanitize 
def get_varname (config,  category_id, variable_id):
    (category, variable) = config.get (category_id, variable_id)
    return (category_id+"_"+variable['id']).upper()

# could not avoid using _sanitize here..
def get_name_comments (config, cid, vid):
    try:
        (category, variable) = config.get (cid, vid)
        (id, name, value, comments) = config._sanitize_variable (cid,variable)
        return (name,comments)
    except:
        return (None,[])

def print_name_comments (config, cid, vid):
    (name,comments)=get_name_comments(config,cid,vid)
    if name:
        print "### %s" % name
    if comments:
        for line in comments:
            print "# %s" % line
    else:
        print "!!! No comment associated to %s_%s" % (cid,vid)

####################
def list_categories (config):
    result=[]
    for (category_id, (category, variables)) in config.variables().iteritems():
        result += [category_id]
    return result

def print_categories (config):
    print "Known categories"
    for cid in list_categories(config):
        print "%s" % (cid.upper())

####################
def list_category (config, cid):
    result=[]
    for (category_id, (category, variables)) in config.variables().iteritems():
        if (cid == category_id):
            for variable in variables.values():
                result += ["%s_%s" %(cid,variable['id'])]
    return result
    
def print_category (config, cid, show_comments=True):
    cid=cid.lower()
    CID=cid.upper()
    vids=list_category(config,cid)
    if (len(vids) == 0):
        print "%s : no such category"%CID
    else:
        print "Category %s contains" %(CID)
        for vid in vids:
            print vid.upper()

####################
def consolidate (default_config, site_config, consolidated_config):
    try:
        conso = PLCConfiguration (default_config)
        conso.load (site_config)
        conso.save (consolidated_config)
    except Exception, inst:
        print "Could not consolidate, %s" % (str(inst))
        return
    print ("Merged\n\t%s\nand\t%s\ninto\t%s"%(default_config,site_config,
                                              consolidated_config))
        
####################
def restart_plc ():
    print ("==================== Stopping %s" % service)
    os.system("service %s stop" % service)
    print ("==================== Starting %s" % service)
    os.system("service %s start" % service)

####################
def prompt_variable (cdef, cread, cwrite, category, variable,
                     show_comments, support_next=False):

    assert category.has_key('id')
    assert variable.has_key('id')

    category_id = category ['id']
    variable_id = variable['id']

    while True:
        default_value = get_value(cdef,category_id,variable_id)
        current_value = get_current_value(cread,cwrite,category_id, variable_id)
        varname = get_varname (cread,category_id, variable_id)
        
        if show_comments :
            print_name_comments (cdef, category_id, variable_id)
        prompt = "== %s : [%s] " % (varname,current_value)
        try:
            answer = raw_input(prompt).strip()
        except EOFError :
            raise Exception ('BailOut')

        # no change
        if (answer == "") or (answer == current_value):
            return None
        elif (answer == "."):
            raise Exception ('BailOut')
        elif (answer == "#"):
            print_name_comments(cread,category_id,variable_id)
        elif (answer == "?"):
            print variable_usage.strip()
        elif (answer == "="):
            print ("%s defaults to %s" %(varname,default_value))
        # revert to default : remove from cwrite (i.e. site-config)
        elif (answer == "/"):
            cwrite.delete(category_id,variable_id)
            print ("%s reverted to %s" %(varname,default_value))
            return
        elif (answer == ">"):
            if support_next:
                raise Exception ('NextCategory')
            else:
                print "No support for next category"
        else:
            variable['value'] = answer
            cwrite.set(category,variable)
            return

def prompt_variables_all (cdef, cread, cwrite, show_comments):
    try:
        for (category_id, (category, variables)) in cread.variables().iteritems():
            print ("========== Category = %s" % category_id.upper())
            for variable in variables.values():
                try:
                    newvar = prompt_variable (cdef, cread, cwrite, category, variable,
                                              show_comments, True)
                except Exception, inst:
                    if (str(inst) == 'NextCategory'): break
                    else: raise
                    
    except Exception, inst:
        if (str(inst) == 'BailOut'): return
        else: raise

def prompt_variables_category (cdef, cread, cwrite, cid, show_comments):
    cid=cid.lower()
    CID=cid.upper()
    try:
        print ("========== Category = %s" % CID)
        for vid in list_category(cdef,cid):
            (category,variable) = cdef.locate_varname(vid.upper())
            newvar = prompt_variable (cdef, cread, cwrite, category, variable,
                                      show_comments, False)
    except Exception, inst:
        if (str(inst) == 'BailOut'): return
        else: raise

####################
def show_variable (cdef, cread, cwrite,
                   category, variable,show_value,show_comments):
    assert category.has_key('id')
    assert variable.has_key('id')

    category_id = category ['id']
    variable_id = variable['id']

    default_value = get_value(cdef,category_id,variable_id)
    current_value = get_current_value(cread,cwrite,category_id,variable_id)
    varname = get_varname (cread,category_id, variable_id)
    if show_comments :
        print_name_comments (cdef, category_id, variable_id)
    if show_value:
        print "%s = %s" % (varname,current_value)
    else:
        print "%s" % (varname)

def show_variables_all (cdef, cread, cwrite, show_value, show_comments):
    for (category_id, (category, variables)) in cread.variables().iteritems():
        print ("========== Category = %s" % category_id.upper())
        for variable in variables.values():
            show_variable (cdef, cread, cwrite,
                           category, variable,show_value,show_comments)

def show_variables_category (cdef, cread, cwrite, cid, show_value,show_comments):
    cid=cid.lower()
    CID=cid.upper()
    print ("========== Category = %s" % CID)
    for vid in list_category(cdef,cid):
        (category,variable) = cdef.locate_varname(vid.upper())
        show_variable (cdef, cread, cwrite, category, variable,
                       show_value,show_comments)

####################
re_mainloop_0arg="^(?P<command>[uUwrqlLsSeEcvVhH\?])[ \t]*$"
re_mainloop_1arg="^(?P<command>[sSeEvV])[ \t]+(?P<arg>\w+)$"
matcher_mainloop_0arg=re.compile(re_mainloop_0arg)
matcher_mainloop_1arg=re.compile(re_mainloop_1arg)

def mainloop (cdef, cread, cwrite, default_config, site_config, consolidated_config):
    while True:
        try:
            answer = raw_input("Enter command (u for usual changes, w to save, ? for help) ").strip()
        except EOFError:
            answer =""
        if (answer == "") or (answer in "?hH"):
            print mainloop_usage
            continue
        groups_parse = matcher_mainloop_0arg.match(answer)
        command=None
        if (groups_parse):
            command = groups_parse.group('command')
            arg=None
        else:
            groups_parse = matcher_mainloop_1arg.match(answer)
            if (groups_parse):
                command = groups_parse.group('command')
                arg=groups_parse.group('arg')
        if not command:
            print ("Unknown command >%s< -- use h for help" % answer)
            continue

        show_comments=command.isupper()
        command=command.lower()

        mode='ALL'
        if arg:
            mode=None
            arg=arg.lower()
            variables=list_category (cdef,arg)
            if len(variables):
                # category_id as the category name
                # variables as the list of variable names
                mode='CATEGORY'
                category_id=arg
            arg=arg.upper()
            (category,variable)=cdef.locate_varname(arg)
            if variable:
                # category/variable as output by locate_varname
                mode='VARIABLE'
            if not mode:
                print "%s: no such category or variable" % arg
                continue

        if (command in "qQ"):
            # todo check confirmation
            return
        elif (command in "wW"):
            try:
                cwrite.save(site_config)
            except:
                print ("Could not save -- fix write access on %s" % site_config)
                break
            print ("Wrote %s" % site_config)
            consolidate(default_config, site_config, consolidated_config)
            print ("You might want to type 'r' (restart plc) or 'q' (quit)")
        elif (command == "u"):
            try:
                for varname in common_variables:
                    (category,variable) = cdef.locate_varname(varname)
                    prompt_variable(cdef, cread, cwrite, category, variable, False)
            except Exception, inst:
                if (str(inst) != 'BailOut'):
                    raise
        elif (command == "r"):
            restart_plc()
        elif (command == "c"):
            print_categories(cread)
        elif (command in "eE"):
            if mode == 'ALL':
                prompt_variables_all(cdef, cread, cwrite,show_comments)
            elif mode == 'CATEGORY':
                prompt_variables_category(cdef,cread,cwrite,category_id,show_comments)
            elif mode == 'VARIABLE':
                try:
                    prompt_variable (cdef,cread,cwrite,category,variable,
                                     show_comments,False)
                except Exception, inst:
                    if (str(inst) != 'BailOut'):
                        raise
        elif (command in "vVsSlL"):
            show_value=(command in "sSlL")
            (c1,c2,c3) = (cdef, cread, cwrite)
            if (command in "lL"):
                (c1,c2,c3) = (cwrite,cwrite,cwrite)
            if mode == 'ALL':
                show_variables_all(c1,c2,c3,show_value,show_comments)
            elif mode == 'CATEGORY':
                show_variables_category(c1,c2,c3,category_id,show_value,show_comments)
            elif mode == 'VARIABLE':
                show_variable (c1,c2,c3,category,variable,show_value,show_comments)
        else:
            print ("Unknown command >%s< -- use h for help" % answer)

####################
def check_dir (config_file):
    dirname = os.path.dirname (config_file)
    if (not os.path.exists (dirname)):
        print "Config file %s located under a non-existing directory" % config_file
        answer=raw_input("Want to create %s [y]/n ? " % dirname)
        answer = answer.lower()
        if (answer == 'n'):
            print "Cannot proceed - good bye"
            sys.exit(1)
        else:
            os.makedirs(dirname,0755)
            if (not os.path.exists (dirname)):
                print "Cannot create dir %s - exiting" % dirname
                sys.exit(1)
            else:
                print "Created directory %s" % dirname

                
####################
def main ():

    command=sys.argv[0]
    argv = sys.argv[1:]

    save = True
    # default is myplc (non -devel) unless -d is specified
    init_flavour("boot")
    optlist,list = getopt.getopt(argv,":dhv")
    for opt in optlist:
        if opt[0] == "-h":
            usage()
        if opt[0] == "-v":
            print ("This is %s - %s" %(command,release_rev))
            sys.exit(1)
        if opt[0] == "-d":
            init_flavour("devel")
            argv=argv[1:]

    if len(argv) == 0:
        (default_config,site_config,consolidated_config) = (def_default_config, def_site_config, def_consolidated_config)
    elif len(argv) == 1:
        (default_config,site_config,consolidated_config) = (argv[0], def_site_config, def_consolidated_config)
    elif len(argv) == 2:
        (default_config, site_config,consolidated_config)  = (argv[0], argv[1], def_consolidated_config)
    elif len(argv) == 3:
        (default_config, site_config,consolidated_config)  = argv
    else:
        usage()

    for c in (default_config,site_config,consolidated_config):
        check_dir (c)

    try:
        # the default settings only - read only
        cdef = PLCConfiguration(default_config)

        # in effect : default settings + local settings - read only
        cread = PLCConfiguration(default_config)

    except:
        print ("default config files not found, is myplc installed ?")
        return 1

    # local settings only, will be modified & saved
    cwrite=PLCConfiguration()
    
    try:
        cread.load(site_config)
        cwrite.load(site_config)
    except:
        cwrite = PLCConfiguration()

    mainloop (cdef, cread, cwrite,default_config, site_config, consolidated_config)
    return 0

if __name__ == '__main__':
    main()