"""sqlpyPlus - extra features (inspired by Oracle SQL*Plus) for Luca Canali's sqlpython.py

Features include:
 - SQL*Plus-style bind variables
 - Query result stored in special bind variable ":_" if one row, one item
 - SQL buffer with list, run, ed, get, etc.; unlike SQL*Plus, buffer stores session's full history
 - @script.sql loads and runs (like SQL*Plus)
 - ! runs operating-system command
 - show and set to control sqlpython parameters
 - SQL*Plus-style describe, spool
 - write sends query result directly to file
 - comments shows table and column comments
 - compare ... to ... graphically compares results of two queries
 - commands are case-insensitive
 - context-sensitive tab-completion for table names, column names, etc.

Use 'help' within sqlpython for details.

Set bind variables the hard (SQL*Plus) way
exec :b = 3
or with a python-like shorthand
:b = 3

- catherinedevlin.blogspot.com  May 31, 2006
"""
# note in cmd.cmd about supporting emacs commands?

descQueries = {
'TABLE': ("""
          atc.column_name,
CASE atc.nullable WHEN 'Y' THEN 'NULL' ELSE 'NOT NULL' END "Null?",
atc.data_type ||
CASE atc.data_type WHEN 'DATE' THEN ''
ELSE '(' ||
CASE atc.data_type WHEN 'NUMBER' THEN TO_CHAR(atc.data_precision) ||
CASE atc.data_scale WHEN 0 THEN ''
ELSE ',' || TO_CHAR(atc.data_scale) END
ELSE TO_CHAR(atc.data_length) END 
END ||
CASE atc.data_type WHEN 'DATE' THEN '' ELSE ')' END
data_type
FROM all_tab_columns atc
WHERE atc.table_name = :object_name
AND      atc.owner = :owner
ORDER BY atc.column_id;""",),
'PROCEDURE': ("""
              NVL(argument_name, 'Return Value') argument_name,             
data_type,
in_out,
default_value
FROM all_arguments
WHERE object_name = :object_name
AND      owner = :owner
AND      package_name IS NULL
ORDER BY sequence;""",),    
'PackageObjects':("""
SELECT DISTINCT object_name
FROM all_arguments
WHERE package_name = :package_name
AND      owner = :owner""",),
'PackageObjArgs':("""
                  object_name,
argument_name,             
data_type,
in_out,
default_value
FROM all_arguments
WHERE package_name = :package_name
AND      object_name = :object_name
AND      owner = :owner
AND      argument_name IS NOT NULL
ORDER BY sequence""",),
'TRIGGER':("""
           description
FROM   all_triggers
WHERE  owner = :owner
AND    trigger_name = :object_name
""",
"""
table_owner,
base_object_type,
table_name,
column_name,
when_clause,
status,
action_type,
crossedition
FROM   all_triggers
WHERE  owner = :owner
AND    trigger_name = :object_name
\\t
""",
),
'INDEX':("""
index_type,
table_owner,
table_name,
table_type,
uniqueness,
compression,
partitioned,
temporary,
generated,
secondary,
dropped,
visibility
FROM   all_indexes
WHERE  owner = :owner
AND    index_name = :object_name
\\t
""",)
}
descQueries['VIEW'] = descQueries['TABLE']
descQueries['FUNCTION'] = descQueries['PROCEDURE'] 

queries = {
'resolve': """
SELECT object_type, object_name, owner FROM (
SELECT object_type, object_name, user owner, 1 priority
FROM   user_objects
WHERE object_name = :objName
UNION ALL
SELECT ao.object_type, ao.object_name, ao.owner, 2 priority
FROM    all_objects ao
JOIN      user_synonyms us ON (us.table_owner = ao.owner AND us.table_name = ao.object_name)
WHERE us.synonym_name = :objName
AND   ao.object_type != 'SYNONYM'
UNION ALL
SELECT ao.object_type, ao.object_name, ao.owner, 3 priority
FROM    all_objects ao
JOIN      all_synonyms asyn ON (asyn.table_owner = ao.owner AND asyn.table_name = ao.object_name)
WHERE asyn.synonym_name = :objName
AND   ao.object_type != 'SYNONYM'
AND      asyn.owner = 'PUBLIC'
UNION ALL 
SELECT 'DIRECTORY' object_type, dir.directory_name, dir.owner, 6 priority
FROM   all_directories dir
WHERE  dir.directory_name = :objName
UNION ALL 
SELECT 'DATABASE LINK' object_type, db_link, owner, 7 priority
FROM   all_db_links dbl
WHERE  dbl.db_link = :objName
) ORDER BY priority ASC,
           length(object_type) ASC,
           object_type DESC""", # preference: PACKAGE before PACKAGE BODY, TABLE before INDEX
'tabComments': """
SELECT comments
FROM    all_tab_comments
WHERE owner = :owner
AND      table_name = :table_name""",
'colComments': """
atc.column_name,
acc.comments             
FROM all_tab_columns atc
JOIN all_col_comments acc ON (atc.owner = acc.owner and atc.table_name = acc.table_name and atc.column_name = acc.column_name)
WHERE atc.table_name = :object_name
AND      atc.owner = :owner
ORDER BY atc.column_id;""",
#thanks to Senora.pm for "refs"
'refs': """
NULL               referenced_by, 
c2.table_name      references, 
c1.constraint_name constraint
FROM
user_constraints c1,
user_constraints c2
WHERE
c1.table_name = :object_name
and c1.constraint_type ='R'
and c1.r_constraint_name = c2.constraint_name
and c1.r_owner = c2.owner
and c1.owner = :owner
UNION
SELECT c1.table_name      referenced_by, 
NULL               references, 
c1.constraint_name constraint
FROM
user_constraints c1,
user_constraints c2
WHERE
c2.table_name = :object_name
and c1.constraint_type ='R'
and c1.r_constraint_name = c2.constraint_name
and c1.r_owner = c2.owner
and c1.owner = :owner       
"""
}

import sys, os, re, sqlpython, cx_Oracle, pyparsing, re, completion
from cmd2 import Cmd, make_option, options, Statekeeper

if float(sys.version[:3]) < 2.3:
    def enumerate(lst):
        return zip(range(len(lst)), lst)

class SoftwareSearcher(object):
    def __init__(self, softwareList, purpose):
        self.softwareList = softwareList
        self.purpose = purpose
        self.software = None
    def invoke(self, *args):
        if not self.software:
            (self.software, self.invokeString) = self.find()            
        argTuple = tuple([self.software] + list(args))
        os.system(self.invokeString % argTuple)
    def find(self):
        if self.purpose == 'text editor':
            software = os.environ.get('EDITOR')
            if software:
                return (software, '%s %s')
        for (n, (software, invokeString)) in enumerate(self.softwareList):
            if os.path.exists(software):
                if n > (len(self.softwareList) * 0.7):
                    print """

                          Using %s.  Note that there are better options available for %s,
                          but %s couldn't find a better one in your PATH.
                          Feel free to open up %s
                          and customize it to find your favorite %s program.

                          """ % (software, self.purpose, __file__, __file__, self.purpose)
                return (software, invokeString)
            stem = os.path.split(software)[1]
            for p in os.environ['PATH'].split(os.pathsep):
                if os.path.exists(os.sep.join([p, stem])):
                    return (stem, invokeString)
        raise (OSError, """Could not find any %s programs.  You will need to install one,
               or customize %s to make it aware of yours.
Looked for these programs:
%s""" % (self.purpose, __file__, "\n".join([s[0] for s in self.softwareList])))
    #v2.4: %s""" % (self.purpose, __file__, "\n".join(s[0] for s in self.softwareList)))

softwareLists = {
    'diff/merge': [  
        ('/usr/bin/meld',"%s %s %s"),
        ('/usr/bin/kdiff3',"%s %s %s"),
        (r'C:\Program Files\Araxis\Araxis Merge v6.5\Merge.exe','"%s" %s %s'),                
        (r'C:\Program Files\TortoiseSVN\bin\TortoiseMerge.exe', '"%s" /base:"%s" /mine:"%s"'),
        ('FileMerge','%s %s %s'),        
        ('kompare','%s %s %s'),   
        ('WinMerge','%s %s %s'),         
        ('xxdiff','%s %s %s'),        
        ('fldiff','%s %s %s'),
        ('gtkdiff','%s %s %s'),        
        ('tkdiff','%s %s %s'),         
        ('gvimdiff','%s %s %s'),        
        ('diff',"%s %s %s"),
        (r'c:\windows\system32\comp.exe',"%s %s %s")],
        'text editor': [
            ('gedit', '%s %s'),
            ('textpad', '%s %s'),
            ('notepad.exe', '%s %s'),
            ('pico', '%s %s'),
            ('emacs', '%s %s'),
            ('vim', '%s %s'),
            ('vi', '%s %s'),
            ('ed', '%s %s'),
            ('edlin', '%s %s')
        ]
}

diffMergeSearcher = SoftwareSearcher(softwareLists['diff/merge'],'diff/merge')
editSearcher = SoftwareSearcher(softwareLists['text editor'], 'text editor')
editor = os.environ.get('EDITOR')
if editor:
    editSearcher.find = lambda: (editor, "%s %s")

class CaselessDict(dict):
    """dict with case-insensitive keys.

    Posted to ASPN Python Cookbook by Jeff Donner - http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/66315"""
    def __init__(self, other=None):
        if other:
            # Doesn't do keyword args
            if isinstance(other, dict):
                for k,v in other.items():
                    dict.__setitem__(self, k.lower(), v)
            else:
                for k,v in other:
                    dict.__setitem__(self, k.lower(), v)
    def __getitem__(self, key):
        return dict.__getitem__(self, key.lower())
    def __setitem__(self, key, value):
        dict.__setitem__(self, key.lower(), value)
    def __contains__(self, key):
        return dict.__contains__(self, key.lower())
    def has_key(self, key):
        return dict.has_key(self, key.lower())
    def get(self, key, def_val=None):
        return dict.get(self, key.lower(), def_val)
    def setdefault(self, key, def_val=None):
        return dict.setdefault(self, key.lower(), def_val)
    def update(self, other):
        for k,v in other.items():
            dict.__setitem__(self, k.lower(), v)
    def fromkeys(self, iterable, value=None):
        d = CaselessDict()
        for k in iterable:
            dict.__setitem__(d, k.lower(), value)
        return d
    def pop(self, key, def_val=None):
        return dict.pop(self, key.lower(), def_val)

class Parser(object):
    comment_def = "--" + pyparsing.ZeroOrMore(pyparsing.CharsNotIn("\n"))    
    def __init__(self, scanner, retainSeparator=True):
        self.scanner = scanner
        self.scanner.ignore(pyparsing.sglQuotedString)
        self.scanner.ignore(pyparsing.dblQuotedString)
        self.scanner.ignore(self.comment_def)
        self.scanner.ignore(pyparsing.cStyleComment)
        self.retainSeparator = retainSeparator
    def separate(self, txt):
        itms = []
        for (sqlcommand, start, end) in self.scanner.scanString(txt):
            if sqlcommand:
                if type(sqlcommand[0]) == pyparsing.ParseResults:
                    if self.retainSeparator:
                        itms.append("".join(sqlcommand[0]))
                    else:
                        itms.append(sqlcommand[0][0])
                else:
                    if sqlcommand[0]:
                        itms.append(sqlcommand[0])
        return itms

bindScanner = Parser(pyparsing.Literal(':') + pyparsing.Word( pyparsing.alphanums + "_$#" ))   
    
def findBinds(target, existingBinds, givenBindVars = {}):
    result = givenBindVars
    for finding, startat, endat in bindScanner.scanner.scanString(target):
        varname = finding[1]
        try:
            result[varname] = existingBinds[varname]
        except KeyError:
            if not givenBindVars.has_key(varname):
                print 'Bind variable %s not defined.' % (varname)                
    return result

class sqlpyPlus(sqlpython.sqlpython):
    defaultExtension = 'sql'
    sqlpython.sqlpython.shortcuts.update({':': 'setbind', '\\': 'psql', '@': '_load'})
    multilineCommands = '''select insert update delete tselect
                      create drop alter'''.split()
    defaultFileName = 'afiedt.buf'
    def __init__(self):
        sqlpython.sqlpython.__init__(self)
        self.binds = CaselessDict()
        self.sqlBuffer = []
        self.settable = ['maxtselctrows', 'maxfetch', 'autobind', 
                         'failover', 'timeout', 'commit_on_exit'] # settables must be lowercase
        self.stdoutBeforeSpool = sys.stdout
        self.spoolFile = None
        self.autobind = False
        self.failover = False
    def default(self, arg, do_everywhere=False):
        sqlpython.sqlpython.default(self, arg, do_everywhere)
        self.sqlBuffer.append(self.query)            

    # overrides cmd's parseline
    def parseline(self, line):
        """Parse the line into a command name and a string containing
        the arguments.  Returns a tuple containing (command, args, line).
        'command' and 'args' may be None if the line couldn't be parsed.        
        Overrides cmd.cmd.parseline to accept variety of shortcuts.."""

        cmd, arg, line = sqlpython.sqlpython.parseline(self, line)
        if cmd in ('select', 'sleect', 'insert', 'update', 'delete', 'describe',
                   'desc', 'comments', 'pull', 'refs', 'desc', 'triggers', 'find') \
           and not hasattr(self, 'curs'):
            print 'Not connected.'
            return '', '', ''
        return cmd, arg, line
    
    do__load = Cmd.do_load

    def onecmd_plus_hooks(self, line):                          
        line = self.precmd(line)
        stop = self.onecmd(line)
        stop = self.postcmd(stop, line)

    def do_shortcuts(self,arg):
        """Lists available first-character shortcuts
        (i.e. '!dir' is equivalent to 'shell dir')"""
        for (scchar, scto) in self.shortcuts.items():
            print '%s: %s' % (scchar, scto)

    def colnames(self):
        return [d[0] for d in curs.description]

    def sql_format_itm(self, itm, needsquotes):
        if itm is None:
            return 'NULL'
        if needsquotes:
            return "'%s'" % str(itm)
        return str(itm)
    def str_or_empty(self, itm):
        if itm is None:
            return ''
        return str(itm)
    def output_as_insert_statements(self):
        usequotes = [d[1] != cx_Oracle.NUMBER for d in self.curs.description]
        def formatRow(row):
            return ','.join(self.sql_format_itm(itm, useq)
                            for (itm, useq) in zip(row, usequotes))
        result = ['INSERT INTO %s (%s) VALUES (%s);' %
                  (self.tblname, ','.join(self.colnames), formatRow(row))
                  for row in self.rows]
        return '\n'.join(result)

    def output_row_as_xml(self, row):
        result = ['  <%s>\n    %s\n  </%s>' %
                  (colname.lower(), self.str_or_empty(itm), colname.lower()) 
                  for (itm, colname) in zip(row, self.colnames)]
        return '\n'.join(result)        
    def output_as_xml(self):
        result = ['<%s>\n%s\n</%s>' %
                  (self.tblname, self.output_row_as_xml(row), self.tblname)
                  for row in self.rows]
        return '\n'.join(result)

    html_template = """<html>
  <head>
    <title py:content="tblname">Table Name</title>
  </head>
  <body>
    <table py:attr="{'id':tblname}">
      <tr>
        <th py:for="colname in colnames">
          <span py:replace="colname">Column Name</span>
        </th>
      </tr>
      <tr py:for="row in rows">
        <td py:for="itm in row">
          <span py:replace="str_or_empty(itm)">Value</span>
        </td>
      </tr>
    </table>
  </body>
</html>"""
    def output_as_html_table(self):
        result = ''.join('<th>%s</th>' % c for c in self.colnames)
        result = ['  <tr>\n    %s\n  </tr>' % result]
        for row in self.rows:
            result.append('  <tr>\n    %s\n  </tr>' %
                          (''.join('<td>%s</td>' %
                                   self.str_or_empty(itm)
                                   for itm in row)))                
        result = '''<table id="%s">
%s
</table>''' % (self.tblname, '\n'.join(result))
        return result

    #TODO: use serious templating to make these user-tweakable

    def output_as_markup(self, genshi_template):
        return None
        #self.tblname, self.colnames, self.rows
            
    def output_as_list(self, align):
        result = []
        colnamelen = max(len(colname) for colname in self.colnames) + 1        
        for (idx, row) in enumerate(self.rows):
            result.append('\n**** Row: %d' % (idx+1))
            for (itm, colname) in zip(row, self.colnames):
                if align:
                    colname = colname.ljust(colnamelen)
                result.append('%s: %s' % (colname, itm))
        return '\n'.join(result)

    tableNameFinder = re.compile(r'from\s+([\w$#_"]+)', re.IGNORECASE | re.MULTILINE | re.DOTALL)          
    def output(self, outformat, rowlimit):
        self.tblname = self.tableNameFinder.search(self.curs.statement).group(1)
        self.colnames = [d[0] for d in self.curs.description]
        if outformat == '\\i':
            result = self.output_as_insert_statements()
        elif outformat ==  '\\x':
            result = self.output_as_xml()
        elif outformat == '\\g':
            result = self.output_as_list(align=False)
        elif outformat == '\\G':
            result = self.output_as_list(align=True)            
        elif outformat in ('\\s', '\\S', '\\c', '\\C'): #csv
            result = []
            if outformat in ('\\s', '\\c'):
                result.append(','.join('"%s"' % colname for colname in self.colnames))
            for row in self.rows:
                result.append(','.join('"%s"' % self.str_or_empty(itm) for itm in row))
            result = '\n'.join(result)
        elif outformat == '\\h':
            result = self.output_as_html_table()
        elif outformat == '\\t':
            rows = [self.colnames]
            rows.extend(list(self.rows))
            transpr = [[rows[y][x] for y in range(len(rows))]for x in range(len(rows[0]))] # matrix transpose
            newdesc = [['ROW N.'+str(y),10] for y in range(len(rows))]
            for x in range(len(self.curs.description)):
                if str(self.curs.description[x][1]) == "<type 'cx_Oracle.BINARY'>":  # handles RAW columns
                    rname = transpr[x][0]
                    transpr[x] = map(binascii.b2a_hex, transpr[x])
                    transpr[x][0] = rname
            newdesc[0][0] = 'COLUMN NAME'
            result = '\n' + sqlpython.pmatrix(transpr,newdesc)            
        else:
            result = sqlpython.pmatrix(self.rows, self.curs.description, self.maxfetch)
        return result

    legalOracle = re.compile('[a-zA-Z_$#]')

    def select_scalar_list(self, sql, binds={}):
        self.curs.execute(sql, binds)
        return [r[0] for r in self.curs.fetchall()]
    
    columnNameRegex = re.compile(
        r'select\s+(.*)from',
        re.IGNORECASE | re.DOTALL | re.MULTILINE)        
    def completedefault(self, text, line, begidx, endidx):
        segment = completion.whichSegment(line)
        text = text.upper()
        completions = []
        if segment == 'select':
            stmt = "SELECT column_name FROM user_tab_columns WHERE column_name LIKE '%s%%'"
            completions = self.select_scalar_list(stmt % (text))
            if not completions:
                stmt = "SELECT column_name FROM all_tab_columns WHERE column_name LIKE '%s%%'"            
                completions = self.select_scalar_list(stmt % (text))
        if segment == 'from':
            columnNames = self.columnNameRegex.search(line)
            if columnNames:
                columnNames = columnNames.group(1)
                columnNames = [c.strip().upper() for c in columnNames.split(',')]
                stmt1 = "SELECT table_name FROM all_tab_columns WHERE column_name = '%s' AND table_name LIKE '%s%%'"
                for columnName in columnNames:
                    # and if columnName is * ?
                    completions.extend(self.select_scalar_list(stmt1 % (columnName, text)))                    
        if segment in ('from', 'update', 'insert into') and (not completions):
            stmt = "SELECT table_name FROM user_tables WHERE table_name LIKE '%s%%'"
            completions = self.select_scalar_list(stmt % (text))
            if not completions:
                stmt = """SELECT table_name FROM user_tables WHERE table_name LIKE '%s%%'
                      UNION
                      SELECT DISTINCT owner FROM all_tables WHERE owner LIKE '%%%s'"""
                completions = self.select_scalar_list(stmt % (text, text))
        if segment in ('where', 'group by', 'order by', 'having', 'set'):
            tableNames = completion.tableNamesFromFromClause(line)
            if tableNames:
                stmt = """SELECT column_name FROM all_tab_columns
                          WHERE table_name IN (%s)""" % \
                       (','.join("'%s'" % (t) for t in tableNames))
            stmt = "%s AND column_name LIKE '%s%%'" % (stmt, text)
            completions = self.select_scalar_list(stmt)
        if not segment:
            stmt = "SELECT object_name FROM all_objects WHERE object_name LIKE '%s%%'"
            completions = self.select_scalar_list(stmt % (text))
        return completions
    
    rowlimitPattern = pyparsing.Word(pyparsing.nums)('rowlimit')
    terminatorPattern = (pyparsing.oneOf('; \\s \\S \\c \\C \\t \\x \\h')    
                        ^ pyparsing.Literal('\n/') ^ \
                        (pyparsing.Literal('\nEOF') + pyparsing.stringEnd)) \
                        ('terminator') + \
                        pyparsing.Optional(rowlimitPattern)
    def do_select(self, arg, bindVarsIn=None, override_terminator=None):
        """Fetch rows from a table.

        Limit the number of rows retrieved by appending
        an integer after the terminator
        (example: SELECT * FROM mytable;10 )

        Output may be formatted by choosing an alternative terminator
        ("help terminators" for details)
        """
        bindVarsIn = bindVarsIn or {}
        statement = self.parsed('select ' + arg)
        self.query = statement.unterminated
        if override_terminator:
            statement['terminator'] = override_terminator
        statement['rowlimit'] = int(statement.rowlimit or 0)
        try:
            self.varsUsed = findBinds(self.query, self.binds, bindVarsIn)
            self.curs.execute(self.query, self.varsUsed)
            self.rows = self.curs.fetchmany(min(self.maxfetch, (statement.rowlimit or self.maxfetch)))
            self.desc = self.curs.description
            self.rc = self.curs.rowcount
            if self.rc > 0:
                self.stdout.write('\n%s\n' % (self.output(statement.terminator, statement.rowlimit)))
            if self.rc == 0:
                print '\nNo rows Selected.\n'
            elif self.rc == 1: 
                print '\n1 row selected.\n'
                if self.autobind:
                    self.binds.update(dict(zip([''.join(l for l in d[0] if l.isalnum()) for d in self.desc], self.rows[0])))
                    if len(self.desc) == 1:
                        self.binds['_'] = self.rows[0][0]
            elif self.rc < self.maxfetch:
                print '\n%d rows selected.\n' % self.rc
            else:
                print '\nSelected Max Num rows (%d)' % self.rc
        except Exception, e:
            print e
            import traceback
            traceback.print_exc(file=sys.stdout)
        self.sqlBuffer.append(self.query)

        
    @options([make_option('-f', '--full', action='store_true', help='get dependent objects as well')])
    def do_pull(self, arg, opts):
        """Displays source code."""

        arg = self.parsed(arg).unterminated        
        object_type, owner, object_name = self.resolve(arg.upper())
        if not object_type:
            return
        self.stdout.write("%s %s.%s\n" % (object_type, owner, object_name))
        self.stdout.write(str(self.curs.callfunc('DBMS_METADATA.GET_DDL', cx_Oracle.CLOB,
                                                 [object_type, object_name, owner])))
        if opts.full:
            for dependent_type in ('OBJECT_GRANT', 'CONSTRAINT', 'TRIGGER'):        
                try:
                    self.stdout.write(str(self.curs.callfunc('DBMS_METADATA.GET_DEPENDENT_DDL', cx_Oracle.CLOB,
                                                             [dependent_type, object_name, owner])))
                except cx_Oracle.DatabaseError:
                    pass

    @options([make_option('-a','--all',action='store_true', help='Find in all schemas (not just my own)'),
              make_option('-i', '--insensitive', action='store_true', help='case-insensitive search'),
              make_option('-c', '--col', action='store_true', help='find column'),
              make_option('-t', '--table', action='store_true', help='find table')])                    
    def do_find(self, arg, opts):
        """Finds argument in source code or (with -c) in column definitions."""

        arg = self.parsed(arg).unterminated.upper()     
        
        if opts.col:
            sql = "owner, table_name, column_name from all_tab_columns where column_name like '%%%s%%'" % (arg)
        elif opts.table:
            sql = "owner, table_name from all_tables where table_name like '%%%s%%'" % (arg)
        else:
            if opts.insensitive:
                searchfor = "LOWER(text)"
                arg = arg.lower()
            else:
                searchfor = "text"
            sql = "* from all_source where %s like '%%%s%%'" % (searchfor, arg)
        if not opts.all:
            sql = '%s and owner = user' % (sql)
        self.do_select(sql)

    @options([make_option('-a','--all',action='store_true',
                          help='Describe all objects (not just my own)')])
    def do_describe(self, arg, opts):
        "emulates SQL*Plus's DESCRIBE"

        arg = self.parsed(arg).unterminated.upper()
        if opts.all:
            which_view = (', owner', 'all')
        else:
            which_view = ('', 'user')

        if not arg:
            self.do_select("""object_name, object_type%s FROM %s_objects WHERE object_type IN ('TABLE','VIEW','INDEX') ORDER BY object_name""" % which_view)
            return
        object_type, owner, object_name = self.resolve(arg)
        if not object_type:
            self.do_select("""object_name, object_type%s FROM %s_objects
                           WHERE object_type IN ('TABLE','VIEW','INDEX')
                           AND   object_name LIKE '%%%s%%'
                           ORDER BY object_name""" %
                           (which_view[0], which_view[1], arg.upper()) )
            return                    
        self.stdout.write("%s %s.%s\n" % (object_type, owner, object_name))
        descQ = descQueries.get(object_type)
        if descQ:
            for q in descQ:
                self.do_select(q,bindVarsIn={'object_name':object_name, 'owner':owner})
        elif object_type == 'PACKAGE':
            packageContents = self.select_scalar_list(descQueries['PackageObjects'][0], {'package_name':object_name, 'owner':owner})
            for packageObj_name in packageContents:
                self.stdout.write('Arguments to %s\n' % (packageObj_name))
                self.do_select(descQueries['PackageObjArgs'][0],bindVarsIn={'package_name':object_name, 'owner':owner, 'object_name':packageObj_name})
    do_desc = do_describe

    def do_deps(self, arg):
        arg = self.parsed(arg).unterminated.upper()        
        object_type, owner, object_name = self.resolve(arg)
        if object_type == 'PACKAGE BODY':
            q = "and (type != 'PACKAGE BODY' or name != :object_name)'"
            object_type = 'PACKAGE'
        else:
            q = ""
        q = """         name,
          type
          from user_dependencies
          where
          referenced_name like :object_name
          and	referenced_type like :object_type
          and	referenced_owner like :owner
          %s""" % (q)
        self.do_select(q, {'object_name':object_name, 'object_type':object_type, 'owner':owner})

    def do_comments(self, arg):
        'Prints comments on a table and its columns.'
        arg = self.parsed(arg).unterminated.upper()        
        object_type, owner, object_name = self.resolve(arg)
        if object_type:
            self.curs.execute(queries['tabComments'],{'table_name':object_name, 'owner':owner})
            self.stdout.write("%s %s.%s: %s\n" % (object_type, owner, object_name, self.curs.fetchone()[0]))
            self.do_select(queries['colComments'],bindVarsIn={'owner':owner, 'object_name': object_name})

    def resolve(self, identifier):
        """Checks (my objects).name, (my synonyms).name, (public synonyms).name
        to resolve a database object's name. """
        parts = identifier.split('.')
        try:
            if len(parts) == 2:
                owner, object_name = parts
                object_type = self.select_scalar_list('SELECT object_type FROM all_objects WHERE owner = :owner AND object_name = :object_name',
                                  {'owner': owner, 'object_name': object_name}
                                  )[0]
            elif len(parts) == 1:
                object_name = parts[0]
                self.curs.execute(queries['resolve'], {'objName':object_name})
                object_type, object_name, owner = self.curs.fetchone()
        except TypeError:
            print 'Could not resolve object %s.' % identifier
            object_type, owner, object_name = '', '', ''
        return object_type, owner, object_name
        #todo: resolve not finding cwm$ table

    def do_resolve(self, arg):
        self.stdout.write(self.resolve(arg)+'\n')

    def spoolstop(self):
        if self.spoolFile:
            self.stdout = self.stdoutBeforeSpool
            print 'Finished spooling to ', self.spoolFile.name
            self.spoolFile.close()
            self.spoolFile = None

    def do_spool(self, arg):
        """spool [filename] - begins redirecting output to FILENAME."""
        self.spoolstop()
        arg = arg.strip()
        if not arg:
            arg = 'output.lst'
        if arg.lower() != 'off':
            if '.' not in arg:
                arg = '%s.lst' % arg
            print 'Sending output to %s (until SPOOL OFF received)' % (arg)
            self.spoolFile = open(arg, 'w')
            self.stdout = self.spoolFile

    def do_write(self, args):
        print 'Use (query) > outfilename instead.'
        return

    def do_compare(self, args):
        """COMPARE query1 TO query2 - uses external tool to display differences.

        Sorting is recommended to avoid false hits.
        Will attempt to use a graphical diff/merge tool like kdiff3, meld, or Araxis Merge, 
        if they are installed."""
        fnames = []
        args2 = args.split(' to ')
        if len(args2) < 2:
            print self.do_compare.__doc__
            return
        for n in range(len(args2)):
            query = args2[n]
            fnames.append('compare%s.txt' % n)
            #TODO: update this terminator-stripping
            if query.rstrip()[-1] != self.terminator: 
                query = '%s%s' % (query, self.terminator)
            self.onecmd_plus_hooks('%s > %s' % (query, fnames[n]))
        diffMergeSearcher.invoke(fnames[0], fnames[1])

    bufferPosPattern = re.compile('\d+')
    rangeIndicators = ('-',':')

    def do_psql(self, arg):
        '''Shortcut commands emulating psql's backslash commands.

        \c connect
        \d desc
        \e edit
        \g run
        \h help
        \i load
        \o spool
        \p list
        \q quit
        \w save
        \db _dir_tablespaces
        \dd comments
        \dn _dir_schemas
        \dt _dir_tables
        \dv _dir_views
        \di _dir_indexes
        \? help psql'''
        commands = {}
        for c in self.do_psql.__doc__.splitlines()[2:]:
            (abbrev, command) = c.split(None, 1)
            commands[abbrev[1:]] = command
        words = arg.split(None,1)
        try:
            abbrev = words[0]
        except IndexError:
            return
        try:
            args = words[1]
        except IndexError:
            args = ''
        try:
            return self.onecmd('%s %s' % (commands[abbrev], args))
        except KeyError:
            print 'psql command \%s not yet supported.' % abbrev

    @options([make_option('-a','--all',action='store_true',
                          help='Describe all objects (not just my own)')])
    def do__dir_tables(self, arg, opts):
        if opts.all:
            which_view = (', owner', 'all')
        else:
            which_view = ('', 'user')        
        self.do_select("""table_name, 'TABLE' as type%s FROM %s_tables WHERE table_name LIKE '%%%s%%'""" %
                       (which_view[0], which_view[1], arg.upper()))        

    @options([make_option('-a','--all',action='store_true',
                          help='Describe all objects (not just my own)')])
    def do__dir_views(self, arg, opts):
        if opts.all:
            which_view = (', owner', 'all')
        else:
            which_view = ('', 'user')        
        self.do_select("""view_name, 'VIEW' as type%s FROM %s_views WHERE view_name LIKE '%%%s%%'""" %
                       (which_view[0], which_view[1], arg.upper())) 

    @options([make_option('-a','--all',action='store_true',
                          help='Describe all objects (not just my own)')])
    def do__dir_indexes(self, arg, opts):
        if opts.all:
            which_view = (', owner', 'all')
        else:
            which_view = ('', 'user')        
        self.do_select("""index_name, index_type%s FROM %s_indexes WHERE index_name LIKE '%%%s%%' OR table_name LIKE '%%%s%%'""" %
                       (which_view[0], which_view[1], arg.upper(), arg.upper())) 

    def do__dir_tablespaces(self, arg):
        self.do_select("""tablespace_name, file_name from dba_data_files""") 

    def do__dir_schemas(self, arg):
        self.do_select("""owner, count(*) AS objects FROM all_objects GROUP BY owner ORDER BY owner""") 

    def do_head(self, arg):
        nrows = 10
        args = arg.split()
        if len(args) > 1:
            for a in args:
                if a[0] == '-':
                    try:
                        nrows = int(a[1:])
                        args.remove(a)
                    except:
                        pass
            arg = ' '.join(args)
        self.do_select('* from %s;%d' % (arg, nrows))

    def do_print(self, arg):
        'print VARNAME: Show current value of bind variable VARNAME.'
        if arg:
            if arg[0] == ':':
                arg = arg[1:]
            try:
                self.stdout.write(str(self.binds[arg])+'\n')
            except KeyError:
                self.stdout.write('No bind variable %s\n' % arg)
        else:
            for (var, val) in self.binds.items():
                print ':%s = %s' % (var, val)

    assignmentScanner = Parser(pyparsing.Literal(':=') ^ '=')
    def do_setbind(self, arg):
        arg = self.parsed(arg).unterminated
        try:
            assigner, startat, endat = self.assignmentScanner.scanner.scanString(arg).next()
        except StopIteration:
            self.do_print(arg)
            return
        var, val = arg[:startat].strip(), arg[endat:].strip()
        if val[0] == val[-1] == "'" and len(val) > 1:
            self.binds[var] = val[1:-1]
            return
        try:
            self.binds[var] = int(val)
            return
        except ValueError:
            try:
                self.binds[var] = float(val)
                return
            except ValueError:
                statekeeper = Statekeeper(self, ('autobind',))  
                self.autobind = True
                self.do_select('%s AS %s FROM dual;' % (val, var))
                statekeeper.restore()

    def do_exec(self, arg):
        if arg[0] == ':':
            self.do_setbind(arg[1:])
        else:
            arg = self.parsed(arg).unterminated
            varsUsed = findBinds(arg, self.binds, {})
            try:
                self.curs.execute('begin\n%s;end;' % arg, varsUsed)
            except Exception, e:
                print e

    '''
    Fails:
    select n into :n from test;'''
    
    def anon_plsql(self, line1):
        lines = [line1]
        while True:
            line = self.pseudo_raw_input(self.continuationPrompt)
            if line.strip() == '/':
                try:
                    self.curs.execute('\n'.join(lines))
                except Exception, e:
                    print e
                return
            lines.append(line)

    def do_begin(self, arg):
        self.anon_plsql('begin ' + arg)

    def do_declare(self, arg):
        self.anon_plsql('declare ' + arg)

    #def do_create(self, arg):
    #    self.anon_plsql('create ' + arg)

    @options([make_option('-l', '--long', action='store_true', help='long descriptions'),
              make_option('-a', '--all', action='store_true', help="all schemas' objects")])        
    def do_ls(self, arg, opts):
        where = ''
        if arg:
            where = """\nWHERE object_type || '/' || object_name
                  LIKE '%%%s%%'""" % (arg.upper().replace('*','%'))
        else:
            where = ''
        if opts.all:
            owner = 'owner'
            whose = 'all'
        else:
            owner = "'' AS owner"
            whose = 'user'
        result = []
        statement = '''SELECT object_type, object_name,
                  status, last_ddl_time, %s
                  FROM   %s_objects %s
                  ORDER BY object_type, object_name''' % (owner, whose, where)
        self.curs.execute(statement)
        for (object_type, object_name, status, last_ddl_time, owner) in self.curs.fetchall():
            if opts.all:
                qualified_name = '%s.%s' % (owner, object_name)
            else:
                qualified_name = object_name
            if opts.long:
                result.append('%s\t%s\t%s/%s' % (status, last_ddl_time, object_type, qualified_name))
            else:
                result.append('%s/%s' % (object_type, qualified_name))
        self.stdout.write('\n'.join(result) + '\n')

    def do_cat(self, arg):
        '''cat TABLENAME --> SELECT * FROM equivalent'''
        targets = arg.split()
        for target in targets:
            self.do_select('* from %s' % target)

    @options([make_option('-i', '--ignore-case', dest='ignorecase', action='store_true', help='Case-insensitive search')])        
    def do_grep(self, arg, opts):
        """grep PATTERN TABLE - search for term in any of TABLE's fields"""    

        arg = self.parsed(arg)
        targetnames = arg.unterminated.split()
        pattern = targetnames.pop(0)
        targets = [] 
        for target in targetnames:
            if '*' in target:
                self.curs.execute("SELECT owner, table_name FROM all_tables WHERE table_name LIKE '%s'%s" %
                                  (target.upper().replace('*','%')), arg.terminator)
                for row in self.curs:
                    targets.append('%s.%s' % row)
            else:
                targets.append(target)
        for target in targets:
            print target
            target = target.rstrip(';')
            sql = []
            try:
                self.curs.execute('select * from %s where 1=0' % target) # just to fill description
                if opts.ignorecase:
                    sql = ' or '.join("LOWER(%s) LIKE '%%%s%%'" % (d[0], pattern.lower()) for d in self.curs.description)                                        
                else:
                    sql = ' or '.join("%s LIKE '%%%s%%'" % (d[0], pattern) for d in self.curs.description)
                sql = '* FROM %s WHERE %s' % (target, sql)
                self.do_select('%s%s%s' % (sql, arg.terminator, arg.rowlimit))
            except Exception, e:
                print e
                import traceback
                traceback.print_exc(file=sys.stdout)                

    def do_refs(self, arg):
        arg = self.parsed(arg).unterminated.upper()        
        object_type, owner, object_name = self.resolve(arg)
        if object_type == 'TABLE':
            self.do_select(queries['refs'],bindVarsIn={'object_name':object_name, 'owner':owner})
    
def _test():
    import doctest
    doctest.testmod()

if __name__ == "__main__":
    "Silent return implies that all unit tests succeeded.  Use -v to see details."
    _test()