# -*- python -*-

# This example reads an lisp-esque syntax configuration
# file to make it easier for non-programmers to use
# Blueshift. It will read a file with the same pathname
# just with ‘.conf’ appended (‘lisp-esque.conf’ in this
# case.) However, if the filename of this file ends with
# with ‘rc’, that part will be removed, for example, if
# you rename this script to ‘~/.blueshiftrc’ it will read
# ‘~/.blueshift.conf’ rather than ‘~/.blueshiftrc.conf’.


# Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
# 
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 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 Affero General Public License for more details.
# 
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.


# Get the name of .conf file
conf = '%s.conf' % (config_file[:-2] if config_file.endswith('rc') else config_file)
# TODO it should be possible to change file


# Read .conf file
with open(conf, 'r') as file:
    conf = file.read()


def abort(text, returncode = 1):
    '''
    Abort the program
    
    @param   text:str        Error message
    @return  returncode:int  The programs return code
    '''
    printerr('\033[01;31m%s\033[00m' % text)
    sys.exit(returncode)


def parse(code):
    '''
    Parse the .conf file and return it as a tree
    
    @param   code:str      The .conf file content to parse
    @return  :list<↑|str>  The root node in the tree
    '''
    stack, stackptr = [], -1
    comment, escape, quote, buf = False, False, None, None
    col, char, line = 0, 0, 1
    
    for c in code:
        if comment:
            if c in '\n\r\f':
                comment = False
        elif escape:
            escape = False
            if   c == 'a':  buf += '\a'
            elif c == 'b':  buf += chr(8)
            elif c == 'e':  buf += '\033'
            elif c == 'f':  buf += '\f'
            elif c == 'n':  buf += '\n'
            elif c == 'r':  buf += '\r'
            elif c == 't':  buf += '\t'
            elif c == 'v':  buf += chr(11)
            elif c == '0':  buf += '\0'
            else:
                buf += c
        elif c == quote:
            quote = None
        elif (c in ';#') and (quote is None):
            if buf is not None:
                stack[stackptr].append(buf)
                buf = None
            comment = True
        elif (c == '(') and (quote is None):
            if buf is not None:
                stack[stackptr].append(buf)
                buf = None
            stackptr += 1
            if stackptr == len(stack):
                stack.append([])
            else:
                stack[stackptr] = []
        elif (c == ')') and (quote is None):
            if buf is not None:
                stack[stackptr].append(buf)
                buf = None
            if stackptr == 0:
                return stack[0]
            stackptr -= 1
            stack[stackptr].append(stack[stackptr + 1])
        elif (c in ' \t\n\r\f') and (quote is None):
            if buf is not None:
                stack[stackptr].append(buf)
                buf = None
        else:
            if buf is None:
                buf = ''
            if c == '\\':
                escape = True
            elif (c in '\'\"') and (quote is None):
                quote = c
            else:
                buf += c
        
        if c == '\t':
            col |= 7
        col += 1
        char += 1
        if c in '\n\r\f':
            line += 1
            col = 0
            char = 0
    
    abort('premature end of file')


# Parse .conf file in tree
conf = parse(conf)


# Parse .conf file tree
if isinstance(conf[0], str) and not conf[0].startswith(':'):
    conf = conf[1:]

## For the following functions, the type of args is the type of args
## after it has been evaluated, they may be functions inside that
## break this until the functions have been evaluated. The type for
## args before evaluation is always list<↑|str>.

def _monitors(mods, args):
    '''
    Select monitors to use by index
    
    @param  mods:[]         Not used
    @param  args:list<str>  Indices of outputs, <screen>: or <screen>:<output> or 'nil', empty for all
    '''
    pass

def _crtc(mods, args):
    '''
    Find monitors by name
    
    @param   mods:[]|[str]   Optionally the number of monitors to list
    @param   args:list<str>  Names of outputs
    @return  :list<str>      <screen>:<output> encoding of found monitors
    '''
    pass

def _size(mods, args):
    '''
    Find monitors by physical size
    
    @param   mods:[]|[str]                     Optionally the number of monitors to list
    @param   args:[str, str]|list<[str, str]>  Width–height-pairs, in millimetres
    @return  :list<str>                        <screen>:<output> encoding of found monitors
    '''
    pass

def _coordinates(mods, args):
    '''
    Specify geographical location by coordinates
    
    @param  mods:[]|[str]    Continuously updates if 'cont' is included
    @param  args:[str, str]  The latitude and longitude (northwards and eastwards in degrees)
    '''
    pass

def _parse(mods, args):
    '''
    Parse a string into a tree
    
    @param   mods:[]       Not used
    @param   args:[str]    The string
    @return  :list<↑|str>  The tree
    '''
    pass

def _read(mods, args):
    '''
    Read an external file
    
    @param   mods:[]     Not used
    @param   args:[str]  The file
    @return  :[str]      The content of the file
    '''
    pass

def _spawn(mods, args):
    '''
    Run an external command
    
    @param   mods:[]         Not used
    @param   args:list<str>  The command
    @return  :[str]          The output of the command
    '''
    pass

def _include(mods, args):
    '''
    Include external files
    
    @param   mods:[]         Not used
    @param   args:list<str>  The files
    @return  :list<↑|str>    The content of the file as a tree concatenated
    '''
    pass

def _source(mods, args):
    '''
    Load external Python files
    
    @param   mods:[]         Not used
    @param   args:list<str>  The files
    '''
    pass

def _eval(mods, args):
    '''
    Evaluate strings of Python code
    
    @param   mods:[]           Not used
    @param   args:list<↑|str>  The strings
    @return  :list<↑|str>      The evaluated valus
    '''
    pass

def _timepoints(mods, args):
    '''
    Select time points when different settings are applied,
    continuous transition betweem them will be used. This are
    not used by default, be can be enabled in the next section.
    
    @param  mods:[]         Not used
    @param  args:list<str>  The time points in 24-hour colour formated as
                            H, H:M or H:M:S, leading zeroes are allowed
    '''
    pass

def _points(mods, args):
    '''
    Select method for calculating the time the different settings are (fully) applied
    
    @param  mods:[]         Not used
    @param  args:list<str>  Either 'solar' optionally followed by solar
                            elevation in degrees, 'time' or 'constant'
    '''
    pass

def _dayness(mods, args):
    '''
    Configure so that adjustments only need day and night settings, time
    settings application points are reduced to different degrees of these
    settings
    
    @param  mods:[]         Not used
    @param  args:list<str>  Mapping from points (implied by index) to dayness degrees
    '''
    pass

def _method(mods, args):
    '''
    Select colour curve applying method
    
    @param  mods:[]         Not used
    @param  args:list<str>  The methods to use: 'randr', 'vidmode', 'print'
    '''
    pass

def _transfrom(mods, args):
    '''
    Let Blueshift transition from the currently applied settings when it starts
    
    @param  mods:[]         Not used
    @param  args:list<str>  Method for (optionally) each monitor: 'randr', 'vidmode' or 'nil'
    '''
    pass

def _negative(mods, args):
    pass

def _invert(mods, args):
    pass

def _temperature(mods, args):
    pass

def _compose(mods, args):
    pass

def _current(mods, args):
    pass

def _brightness(mods, args):
    pass

def _contrast(mods, args):
    pass

def _resolution(mods, args):
    pass

def _gamma(mods, args):
    pass

def _pgamma(mods, args):
    pass

def _clip(mods, args):
    pass

def _sigmoid(mods, args):
    pass

def _limits(mods, args):
    pass

def _linearise(mods, args):
    pass

def _manipulate(mods, args):
    pass

def _standardise(mods, args):
    pass