#!/usr/bin/env python
#Copyright Joel Schaerer 2008-2010
#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, print_function

try: # fix to get optimised pickle in python < 3
    import cPickle as pickle
except ImportError:
    import pickle

import getopt
from sys import argv, stderr, version_info
from tempfile import NamedTemporaryFile
from operator import itemgetter
import os
import signal
MAX_KEYWEIGHT = 1000
MAX_STORED_PATHS = 600
COMPLETION_SEPARATOR = '__'
CONFIG_DIR = os.environ.get("AUTOJUMP_DATA_DIR", os.path.expanduser("~"))

def uniqadd(collection, key):
    """Adds a key to a list only if it is not already present"""
    if key not in collection:
        collection.append(key)

def dicadd(dic, key, increment=1):
    """Increment a value in a dic, set it to 0
    if is is not already present"""
    dic[key] = dic.get(key, 0.)+increment

def save(path_dict, dic_file):
    f = NamedTemporaryFile(dir=CONFIG_DIR, delete=False)
    pickle.dump(path_dict, f, -1)
    f.flush()
    os.fsync(f)
    f.close()
    #cf. http://thunk.org/tytso/blog/2009/03/15/dont-fear-the-fsync/
    os.rename(f.name, dic_file) 
    try: #backup file
        import time 
        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 as e:
        print("Error while creating backup autojump file. (%s)" % e,
                file=stderr)

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()) 
    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

def match(path, pattern, ignore_case=False, only_end=False):
    try:
        if os.path.realpath(os.curdir) == path : return False
    #Sometimes the current path doesn't exist anymore.
    #In that case, jump if possible.
    except OSError:
        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, 'rb')
        if version_info[0]>2:
            #encoding is only specified for python2.x compatibility
            path_dict = pickle.load(aj_file, encoding="utf-8")
        else:
            path_dict = pickle.load(aj_file)
        aj_file.close()
        return path_dict
    except (IOError, EOFError, pickle.UnpicklingError):
        if not error_recovery and os.path.exists(dic_file+".bak"):
            print('Problem with autojump database,\
                    trying to recover from backup...', file=stderr)
            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 as e:
    print("Unknown command line argument: %s" % e)
    exit(1)

if CONFIG_DIR == os.path.expanduser("~"):
    dic_file = CONFIG_DIR+"/.autojump_py"
else:
    dic_file = CONFIG_DIR+"/autojump_py"
path_dict = open_dic(dic_file)
if ('-a', '') in optlist:
    # The home dir can be reached quickly by "cd"
    # and may interfere with other directories
    if(args[-1] != os.path.expanduser("~")): 
        dicadd(path_dict, args[-1])
        save(path_dict, dic_file)
elif ('--stat', '') in optlist:
    a = list(path_dict.items())
    a.sort(key=itemgetter(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])
    pickle.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])
    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])
        if endmatch:  #user has selected a completion
            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 = list(path_dict.items())
        dirs.sort(key=itemgetter(1), reverse=True)
        if completion or userchoice != -1:
            max_matches = 9
        else:
            max_matches = 1
        find_matches(dirs, patterns, results, False, max_matches)
        # If not found, try ignoring case.
        # On completion always show all results
        if completion or not results: 
            find_matches(dirs, patterns, results,
                    ignore_case=True, max_matches=max_matches) 
        # Keep the database to a reasonable size
        if not completion and clean_dict(dirs, path_dict):
            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)