#!/usr/bin/python
# Author: Luca Marturana (luca89) <lucamarturana@gmail.com>

# This program 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 2 of the License, or
# (at your option) any later version.
#
# This program 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 this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

from __future__ import print_function

import os
import sys
import re
from datetime import datetime
import curses
import curses.ascii
import textwrap
from portage import settings as port_settings
from glob import glob
import gettext
import locale
import gzip
import bz2

no_liblzma = False
try:
    import liblzma
except ImportError:
    no_liblzma = True

# Setup default locale
locale.setlocale(locale.LC_ALL, '')

# Setup gettext. Note that lgettext() is used instead of gettext()
# because it always returns strings encoded with the preferred system
# encoding, not encoded with the same codeset used in the translation
# file
gettext.textdomain('elogv')
_ = gettext.lgettext

# This text is used on the in-line help
helptext = _("""
Elogv is a portage elog viewer based on curses and python,
you can use these keys to control the behavior of the program:

 - Down arrow or j -> scroll the list of files down by 1 unit
 - Up arrow or k -> opposite of Down arrow
 - PageDown -> scroll the list down by 10 unit
 - PageUp -> opposite of PageDown
 - End -> go to the last file of the list
 - Home -> go to the first file of the list
 - t -> order the list of files by date, most recent on top
 - a -> order the list of files alphabetically, the first time by category,
        the second time (pressing the key again) by package name
 - c -> order the list of files by log class warning level
 - r -> reverse the list of files
 - SpaceBar -> scroll the selected file
 - h or F1 -> show the help screen, press Page Up/Down to scroll up and down,
              h or F1 again to hide
 - d -> removes selected files, usage is similar to vim "d" command,
        here are same examples:
            da -> removes all files
            de -> removes from selected item to the end of the list
            ds -> remove from selected item to the start of the list
            d1d or dd -> removes selected file only
            d4d -> removes 4 files starting from selected one
 - / -> starts a search prompt, write a string and will be showed the next
        package that contains your string, use ESC to exit
 - q -> quit
""")

(normal, selected, einfo, elog, ewarn, eerror) = range(6)
(PATH, CAT, PN, DATE, CLASS) = range(5)

# Character used to print the class of an elog
class_char = "*"
list_format = "%s/%s - %s"
date_format = "%x"

# Exceptions classes
class TermTooSmall(Exception):
    def __init__(self):
        pass

class NoLogFiles(Exception):
    def __init__(self):
        pass

class CannotOpenElogdir(Exception):
    def __init__(self):
        pass

# Main class (called with curses.wrapper later)
class ElogViewer:
    def __init__(self, screen):
        #curses.curs_set(0)
        self.screen = screen

        # Our color pairs
        try:
            curses.use_default_colors()
            curses.init_pair(selected, curses.COLOR_BLACK, curses.COLOR_WHITE)
            curses.init_pair(einfo, curses.COLOR_GREEN, curses.COLOR_BLACK)
            curses.init_pair(ewarn, curses.COLOR_YELLOW, curses.COLOR_BLACK)
            curses.init_pair(eerror, curses.COLOR_RED, curses.COLOR_BLACK)
            curses.init_pair(elog, curses.COLOR_MAGENTA, curses.COLOR_BLACK)
        except curses.error:  # e.g. with "TERM=vt100 elogv" invokation
            pass

        # This attributes are used to manage the scrolling of the list
        # of files    
        self.pposy = 0
        self.usel = 0

        # Method used to order the list: use DATE for order by date, CAT to
        # order by category name, PN to order by package name, CLASS to order
        # by class second value set if the list should be reversed (True o False)
        self.sort_method = [ DATE, False]

        # Initialize screen
        self.init_screen()

        c = self.screen.getch()
        while c not in ( ord("q"), curses.ascii.ESC):
            ## Scrolling keys ##
            if c in (curses.KEY_DOWN, ord("j")):
                self.change_usel(1)

            elif c in (curses.KEY_UP, ord("k")):
                self.change_usel(-1)

            elif c in (curses.KEY_NPAGE, ord("f")):
                self.change_usel(10)
                
            elif c in (curses.KEY_PPAGE, ord("b")):
                self.change_usel(-10)

            elif c in (curses.KEY_END, ord("G")):
                self.change_usel(len(self.packages)-1, False)

            elif c in (curses.KEY_HOME, ord("g")):
                self.change_usel(0, False)
            ## End Scrolling keys ##

            ## Sorting the list ##
            elif c == ord("a"):
                if self.sort_method[0] == CAT:
                    self.sort_method[0] = PN
                else:
                    self.sort_method[0] = CAT
                self.fill_file_pad()
                self.refresh_file_pad()

            elif c == ord("t"):
                self.sort_method[0] = DATE
                self.fill_file_pad()
                self.refresh_file_pad()

            elif c == ord("c"):
                self.sort_method[0] = CLASS
                self.fill_file_pad()
                self.refresh_file_pad()

            elif c == ord("r"):
                self.sort_method[1] = not self.sort_method[1]
                self.fill_file_pad()
                self.refresh_file_pad()
            ## End Sorting the list ##

            elif c == ord(" "):
                # Now is used only for scrolling the text
                self.show_log()

            elif c == curses.KEY_RESIZE:
                # Reinitialize screen
                self.init_screen()

            elif c in (curses.KEY_F1, ord("h")):
                self.show_help()
                # We need to reinitialize the screen
                self.init_screen()

            elif c == ord("d"):
                subc = self.screen.getch()
                if subc == ord("a"):
                    n = "all"
                elif subc == ord("e"):
                    n = "end"
                elif subc == ord("s"):
                    n = "start"
                elif subc == ord("d"):
                    n = "1"
                else:
                    n = ""
                    while curses.ascii.isdigit(subc):
                        n += chr(subc)
                        subc = self.screen.getch()
                if n:
                    self.remove_file(n)
                    self.file_pad.erase()
                    self.refresh_file_pad()
                    # If the user deleted files to start, move the selection
                    # to the first item
                    if n == "start":
                        self.usel = 0
                        self.pposy = 0
                    self.fill_file_pad()
                    self.refresh_file_pad()
                    self.logf_wrap = self.wrap_logf_lines()
                    self.show_log()

            elif c == ord("/"):
                word = ""
                self.screen.move(self.height-1,2)
                self.screen.addstr("/")
                subc = self.screen.getch()
                while subc != curses.ascii.ESC:
                    if subc == ord("\n"):
                        self.search(word,1)
                    elif subc == curses.ascii.BS:
                        word = word[:-1]
                        self.screen.delch()
                        self.search(word)
                    elif curses.ascii.isalpha(subc):
                        word += chr(subc)
                        self.screen.addstr(chr(subc))
                        self.search(word)  
                    subc = self.screen.getch()
                self.screen.hline(self.height-1,2,curses.ACS_HLINE,(len(word)+1))
                self.screen.addstr(self.height-2,2," "*20)

            # Get another key from the user
            c = self.screen.getch()

    def init_screen(self):
        """
        Init the screen and wins, it's also used to reinizialize screen
        after a terminal resizing
        """
        (self.height, self.width) = self.screen.getmaxyx()

        # Check if the terminal window is too small
        if self.height < 12 or self.width < 80:
            raise TermTooSmall()

        # Screen Look&Feel
        self.screen.border()
        self.screen.hline(self.height//2,1, "_", self.width-2)
        m = _(" Press F1 or h to show the help screen ")
        self.screen.addstr(self.height-1, self.width-len(m)-1, m)
        self.screen.refresh()

        # Initialize log file window
        self.log_win = curses.newwin(self.height//2-2, self.width-2,
                                     self.height//2+1, 1)

        # Draw other window of the screen
        self.fill_file_pad()
        self.refresh_file_pad()

        self.logf_wrap = self.wrap_logf_lines()
        self.show_log()

    def change_usel(self,n,relative=True):
        prev_usel = self.usel
        if not relative:
            self.usel = n
        elif n < 0 and self.usel+n < 0:
            self.usel = 0
        elif n > 0 and self.usel+n > len(self.packages)-1:
            self.usel = len(self.packages)-1
        else:
            self.usel += n

        prev_pkg = self.packages[prev_usel]
        pkg = self.packages[self.usel]
        self.file_pad.addstr(prev_usel,1,
                                 class_char,
                                 curses.A_BOLD + curses.color_pair(prev_pkg[CLASS]))
        self.file_pad.addstr(prev_usel,3,
                                 list_format % (prev_pkg[CAT], prev_pkg[PN], prev_pkg[DATE].strftime(date_format) ),
                                 curses.color_pair(normal))
        self.file_pad.addstr(self.usel,1,
                                 class_char,
                                 curses.A_BOLD + curses.color_pair(pkg[CLASS]))
        self.file_pad.addstr(self.usel,3,
                                 list_format % (pkg[CAT], pkg[PN], pkg[DATE].strftime(date_format) ),
                                 curses.color_pair(selected))

        first = self.pposy
        last = (self.height / 2 - 2) + first

        if self.usel < first:
            self.pposy -= first - self.usel

        if self.usel > last:
            self.pposy += self.usel - last
        self.refresh_file_pad()
        self.logf.close()
        try:
            self.openfile(pkg[PATH])
        except IOError:
            # print(("Logfile not found at '%s'. Did it get deleted somehow?"
            #     % os.path.join(elogdir,pkg[PATH])))
            self.init_screen()
            self.change_usel(prev_usel, False)
        self.logf_wrap = self.wrap_logf_lines()
        self.show_log()

    def openfile(self, myfile):
        if myfile.endswith('.xz'):
            if not no_liblzma:
                self.logf = liblzma.LZMAFile(myfile)
            else:
                sys.exit('You need pyliblzma library to be able to read xz compressed elog files.\nhttp://pypi.python.org/pypi/pyliblzma')
        elif myfile.endswith('.gz'):
            self.logf = gzip.open(myfile)
        elif myfile.endswith('.bz2'):
            self.logf = bz2.BZ2File(myfile)
        else:
            self.logf = open(myfile)

    def refresh_file_pad(self):
        """
        Redraws file pad, first half of the screen.
        Can be used to scroll or simply update
        """
        self.file_pad.refresh(self.pposy,0,1,1,self.height//2-1,self.width-2)

    def get_packages_key(self, k):
        return k[self.sort_method[0]]

    def fill_file_pad(self):
        """
        Fill the list of files, colorize the selected row and order files by
        method specified
        """
        # Get the list of files
        try:
            file_list = glob(os.path.join(elogdir,"*:*:*.log*")) + glob(os.path.join(elogdir,"*","*:*.log*"))
        except OSError:
            raise CannotOpenElogdir()

        if not file_list:
            raise NoLogFiles()

        # self.packages contains all info extracted from each file, this is the
        # structure:
        # [ ("filename", "category", "package name", date:datetime_obj, class:int), ... ]
        self.packages = []
        for filepath in file_list:
            # This istruction splits the information about the package from the file path
            # If the user don't use split-elog feature the format used by portage is:
            # <elogdir>/x11-themes:haematite-xcursors-1.0:20091018-195827.log
            # else with the split-elog feature:
            # <elogdir>/x11-themes/haematite-xcursors-1.0:20091018-195827.log
            # So first we remove the elogdir from the filepath to obtain
            # x11-themes:haematite-xcursors-1.0:20091018-195827.log
            # or
            # x11-themes/haematite-xcursors-1.0:20091018-195827.log
            # then we split the string using as pattern / or : to obtain in any
            # case
            # ( "x11-themes", "haematite-xcursors", "1.0:20091018-195827.log")
            tmpfilepath = re.sub('\.log.*$', '.log', filepath)
            split_up = re.split(":|" + os.path.sep, tmpfilepath.replace(elogdir + os.path.sep, ""))
            if len(split_up) < 3:
                continue
            (cat, pn, other) = split_up[-3:]
            if sys.version_info[:2] >= (2, 5):
                date = datetime.strptime(other, "%Y%m%d-%H%M%S.log")
            else:
                # This is for backward compatibility with older version of python
                # it will be removed in the future
                date_str = other[:8]
                date = datetime(int(date_str[:4]),int(date_str[4:6]),int(date_str[6:]))
            self.packages.append( (filepath, cat, pn, date, self.get_class(filepath)) )

        # Maybe that after removing files self.usel points to a wrong index,
        # so this will prevent a crash
        if self.usel >= len(self.packages):
            self.usel = len(self.packages)-1
            # We also have to update self.pposy
            if self.pposy > self.usel:
                self.pposy = max(0, self.usel-10)

        # Sort the list
        if self.sort_method[0] in (DATE, CLASS):
            self.packages.sort(key=self.get_packages_key,reverse=not self.sort_method[1])
        else:
            self.packages.sort(key=self.get_packages_key, reverse=self.sort_method[1])

        self.file_pad = curses.newpad(len(self.packages),self.width)
        self.file_pad.erase()

        for i in range(len(self.packages)):
            pkg = self.packages[i]
            if i == self.usel:
                cp = selected
                # Maybe that the logf pointed by self.usel changed, (example
                # when same files are removed) so reload the self.logf file
                # pointer, this work is done here for convenience
                try:
                    self.logf.close()
                except AttributeError:
                    pass
                self.openfile(pkg[PATH])
            else:
                cp = normal

            self.file_pad.addstr(i,1,
                                 class_char,
                                 curses.A_BOLD + curses.color_pair(pkg[CLASS]))
            self.file_pad.addstr(i,3,
                                 list_format % (pkg[CAT], pkg[PN], pkg[DATE].strftime(date_format) ),
                                 curses.color_pair(cp))

    def get_class(self,filepath):
        """
        Get the highest elog class in a file
        """
        f = file(filepath)

        classes = re.findall("LOG:|INFO:|WARN:|ERROR:", f.read())
        f.close()

        if "ERROR:" in classes:
            return eerror
        elif "WARN:" in classes:
            return ewarn
        elif "LOG:" in classes:
            return elog
        else:
            return einfo

    def wrap_logf_lines(self):
        """
        Takes a file-like object and wraps long lines. Returns a list iterator.
        """
        result = []
        self.logf.seek(0)
        logf = self.logf.readlines()
        for line in logf:
            if not line.strip():
                # textwrap eats newlines
                result.append("\n")
            else:
                # Returns a list of new lines minus the line ending \n
                wrapped_line = textwrap.wrap(line, width=self.width-2)
                for l in wrapped_line:
                    l += "\n" 
                    result.append(l)

        return iter(result)

    def show_log(self):
        """
        Display the selected file, if the length of the file is bigger than
        the height of the window, interrupt the drawing and resume it when the
        user press again the SpaceBar key
        """
        self.log_win.erase()
        shown_all = False

        for i in range(0,self.height//2-4):
            try:
                x = self.logf_wrap.next()
            except StopIteration:
                shown_all = True
                # Restart the iterator
                self.logf_wrap = self.wrap_logf_lines()
                break

            try:
                if x.startswith('INFO:'):
                    self.log_win.addstr(x[:self.width-2],curses.color_pair(einfo))
                elif x.startswith('WARN:'):
                    self.log_win.addstr(x[:self.width-2],curses.color_pair(ewarn))
                elif x.startswith('ERROR:'):
                    self.log_win.addstr(x[:self.width-2],curses.color_pair(eerror))
                elif x.startswith('LOG:'):
                    self.log_win.addstr(x[:self.width-2],curses.color_pair(elog))
                else:
                    self.log_win.addstr(x[:self.width-2],curses.color_pair(normal))
            except curses.error:
                pass

        if not shown_all: 
            s = _("Continue...")
            self.log_win.addstr(self.height//2-3, self.width-len(s)-4, s,
                                curses.color_pair(normal))

        self.log_win.refresh()

    def remove_file(self,n):
        """
        Delete from the filesystem a slice of elog files
        n can be:
        "all" -> all files will be deleted
        "end" -> files from selected one to the end of the list will be deleted
        <int> -> will be deleted the selected file and the next <int>-1
        """

        if n == "all":
            start = None
            end = None
        elif n == "end":
            start = self.usel
            end = None
        elif n == "start":
            start = None
            end = self.usel
        else:
            start = self.usel
            end = self.usel + int(n)

        for item in self.packages[start:end]:
            os.remove(os.path.join(elogdir,item[0]))

    def show_help(self):
        # Setup help window
        helpwin_height = self.height / 3 * 2
        helpwin_corner = (self.height / 6, self.width// 2 - 40)
        helpwin = curses.newwin(helpwin_height, 80,
                                     helpwin_corner[0], helpwin_corner[1])
        helplines = helptext.splitlines()

        # Setup help pad
        row = 0
        maxrow = len(helplines)
        helppad = curses.newpad(maxrow,80)

        # Insert helptext on the pad
        for i in range(maxrow):
            helppad.addstr(i,0,helplines[i])

        # Loop to manage user actions
        c = None
        while c not in (ord("h"), curses.KEY_F1, ord("q")):
            helpwin.erase()
            helpwin.border()
            helpwin.refresh()

            helppad.refresh(row,0,helpwin_corner[0]+1,helpwin_corner[1]+1,
                             helpwin_height+helpwin_corner[0]-2,80+helpwin_corner[1]-2)

            c = self.screen.getch()
            if c == curses.KEY_NPAGE:
                if row+10 <= maxrow:
                    row += 10
            elif c == curses.KEY_PPAGE:
                if row-10 >= 0:
                    row -= 10
            elif c in (curses.KEY_DOWN, ord("j")):
                if row+1 < maxrow:
                    row += 1
            elif c in (curses.KEY_UP, ord("k")):
                if row > 0:
                    row -= 1

    def search(self, word, div=0):
        for x in self.packages[self.usel+div:]:
            if re.search(word, "%s/%s" % x[1:3]):
                self.change_usel(self.packages.index(x),False)
                break
        else:
            self.screen.addstr(self.height-2,2,_("Not Found!"),
                curses.color_pair(eerror))

if __name__ == "__main__":
    if "--help" in sys.argv:
        print(helptext)
        sys.exit()

    # Get the path of the elogdir
    if port_settings['PORT_LOGDIR']:
        elogdir = os.path.join(port_settings['PORT_LOGDIR'],"elog")
    else:
        elogdir = os.path.join(os.sep,port_settings['EPREFIX'],"var","log","portage","elog")

    # Launch curses interface
    try:
        curses.wrapper(ElogViewer)
    except TermTooSmall:
        print(_("Your terminal window is too small, try to enlarge it"))
        sys.exit(1)
    except NoLogFiles:
        print(_("There aren't any elog files on"), elogdir)
        sys.exit(1)
    except CannotOpenElogdir:
        print(_("Cannot open"), elogdir)
        print(_("Please check if the directory exists and if it's readable by your user."))
        sys.exit(1)
    except KeyboardInterrupt:
        pass
# vim: set shiftwidth=4 tabstop=4 expandtab: