#!/usr/bin/python
#Copyright Joel Schaerer 2008, 2009
#This file is part of autojump

#autojump is free software: you can redistribute it and/or modify
#it under the terms of the GNU General Public License as published by
#the Free Software Foundation, either version 3 of the License, or
#(at your option) any later version.
#
#autojump is distributed in the hope that it will be useful,
#but WITHOUT ANY WARRANTY; without even the implied warranty of
#MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#GNU General Public License for more details.
#
#You should have received a copy of the GNU General Public License
#along with autojump.  If not, see <http://www.gnu.org/licenses/>.

from __future__ import division
import cPickle
import getopt
from sys import argv,exit,stderr
import os
import signal
max_keyweight=1000
max_stored_paths=400
completion_separator='__'

def signal_handler(arg1,arg2):
    print "Received SIGINT, trying to continue"
signal.signal(signal.SIGINT,signal_handler) #Don't break on sigint

def uniqadd(list,key):
    if key not in list:
        list.append(key)

def dicadd(dic,key,increment=1):
    dic[key]=dic.get(key,0.)+increment

def save(path_dict,dic_file):
    f=open(dic_file+".tmp",'w')
    cPickle.dump(path_dict,f,-1)
    f.flush()
    os.fsync(f)
    f.close()
    try:
        os.rename(dic_file+".tmp",dic_file) #cf. http://thunk.org/tytso/blog/2009/03/15/dont-fear-the-fsync/
        import time #backup file
        if not os.path.exists(dic_file+".bak") or time.time()-os.path.getmtime(dic_file+".bak")>86400:
            import shutil
            shutil.copy(dic_file,dic_file+".bak")
    except OSError:
        pass #Fail quietly, this usually means a concurrent autojump process already did the job

def forget(path_dict,dic_file):
    """Gradually forget about directories. Only call from the actual jump since it can take time"""
    keyweight=sum(path_dict.values()) #Gradually forget about old directories
    if keyweight>max_keyweight: 
        for k in path_dict.keys():
            path_dict[k]*=0.9*max_keyweight/keyweight
        save(path_dict,dic_file)

def clean_dict(sorted_dirs,path_dict):
    """Limits the sized of the path_dict to max_stored_paths. Returns True if keys were deleted"""
    if len(sorted_dirs) > max_stored_paths:
        #remove 25 more than needed, to avoid doing it every time
        for dir,dummy in sorted_dirs[max_stored_paths-25:]:
            del path_dict[dir]
        return True
    else: return False

# catch all unavailable (python < 2.5)
try:
    all
except:
    def all(iterable):
        for element in iterable:
            if not element:
                return False
        return True

def match(path,pattern,ignore_case=False,only_end=False):
    try:
        if os.path.realpath(os.curdir)==path : return False
    except OSError: #sometimes the current path doesn't exist anymore. In that case, jump if possible.
        pass
    if only_end:
        match_string = "/".join(path.split('/')[-1-pattern.count('/'):])
    else:
        match_string = path
    if ignore_case:
        match=(match_string.lower().find(pattern.lower()) != -1)
    else:
        match=(match_string.find(pattern) != -1)
    #return true if there is a match and the path exists (useful in the case of external drives, for example)
    return match and os.path.exists(path) 

def find_matches(dirs,patterns,result_list,ignore_case,max_matches):
    """Find max_matches paths that match the pattern, and add them to the result_list"""
    for path,count in dirs:
        if len(result_list) >= max_matches : break
        #For the last pattern, only match the end of the pattern
        if all(match(path,p,ignore_case, only_end = (n==len(patterns)-1)) for n,p in enumerate(patterns)):
            uniqadd(result_list,path)

def open_dic(dic_file,error_recovery=False):
    try:
        aj_file=open(dic_file)
        path_dict=cPickle.load(aj_file)
        aj_file.close()
        return path_dict
    except (IOError,EOFError,cPickle.UnpicklingError):
        if not error_recovery and os.path.exists(dic_file+".bak"):
            print >> stderr, 'Problem with autojump database, trying to recover from backup...'
            import shutil
            shutil.copy(dic_file+".bak",dic_file)
            return open_dic(dic_file,True)
        else: return {} #if everything fails, return an empty file

#Main code
try:
    optlist, args = getopt.getopt(argv[1:], 'a',['stat','import','completion', 'bash']) 
except getopt.GetoptError, e:
    print "Unknown command line argument: %s" % e
    exit(1)

dic_file=os.path.expanduser("~/.autojump_py")
path_dict=open_dic(dic_file)
if ('-a','') in optlist:
    if(args[-1] != os.path.expanduser("~")): # home dir can be reached quickly by "cd" and may interfere with other directories
        dicadd(path_dict,args[-1])
        save(path_dict,dic_file)
elif ('--stat','') in optlist:
    a=path_dict.items()
    a.sort(key=lambda e:e[1])
    for path,count in a[-100:]:
        print "%.1f:\t%s" % (count,path)
    print "Total key weight: %d. Number of stored paths: %d" % (sum(path_dict.values()),len(a))
elif ('--import','') in optlist:
    for i in open(args[-1]).readlines():
        dicadd(path_dict,i[:-1])
    cPickle.dump(path_dict,open(dic_file,'w'),-1)
else:
    import re
    completion=False
    userchoice=-1 #i if the pattern is of the form __pattern__i, otherwise -1
    results=[]
    if ('--completion','') in optlist:
        completion=True
    else:
        forget(path_dict,dic_file) #gradually forget about old directories
    if not args: patterns=[""]
    else: patterns=args

    #if the last pattern contains a full path, jump there
    #the regexp is because we need to support stuff like "j wo jo__3__/home/joel/workspace/joel" for zsh
    last_pattern_path = re.sub("(.*)"+completion_separator,"",patterns[-1])
    #print >> stderr, last_pattern_path
    if len(last_pattern_path)>0 and last_pattern_path[0]=="/" and os.path.exists(last_pattern_path):
        if not completion : print last_pattern_path
    else:
        #check for ongoing completion, and act accordingly
        endmatch=re.search(completion_separator+"([0-9]+)",patterns[-1]) #user has selected a completion
        if endmatch:
            userchoice=int(endmatch.group(1))
            patterns[-1]=re.sub(completion_separator+"[0-9]+.*","",patterns[-1])
        else: #user hasn't selected a completion, display the same choices again
            endmatch=re.match("(.*)"+completion_separator,patterns[-1])
            if endmatch: patterns[-1]=endmatch.group(1)

        dirs=path_dict.items()
        dirs.sort(key=lambda e:e[1],reverse=True)
        if completion:
            max_matches = 9
        else:
            max_matches = 1
        find_matches(dirs,patterns,results,False,max_matches)
        if completion or not results: #if not found, try ignoring case. On completion always show all results
            find_matches(dirs,patterns,results,ignore_case=True,max_matches=max_matches) 
        if not completion and clean_dict(dirs,path_dict): #keep the database to a reasonable size
            save(path_dict,dic_file)

        if completion and ('--bash', '') in optlist: quotes='"'
        else: quotes=""

        if userchoice!=-1:
            if len(results) > userchoice-1 : print quotes+results[userchoice-1]+quotes
        elif len(results) > 1 and completion:
            print "\n".join(("%s%s%d%s%s" % (patterns[-1],completion_separator,n+1,completion_separator,r)\
                for n,r in enumerate(results[:8])))
        elif results: print quotes+results[0]+quotes