#! /usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Copyright 2022, Nils Hilbricht, Germany ( https://www.hilbricht.net )

This file is part of the Laborejo Software Suite ( https://www.laborejo.org ),

Laborejo2 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.

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, see <http://www.gnu.org/licenses/>.
"""

"""Use generated music data and build a complete lilypond file from it"""

import logging; logger = logging.getLogger(__name__); logger.info("import")

#Standard Library Modules
import os.path
from datetime import date
import subprocess
from tempfile import gettempdir

#Third Party Modules

#Template Modules
from template.start import PATHS

#Our modules


da = date.fromordinal(730920) # 730920th day after 1. 1. 0001

def saveAsLilypond(score, absoluteFilePath = None):
    #absoluteFilePath = self.absoluteFilePath + ".ly" if (not absoluteFilePath) else absoluteFilePath
    assert absoluteFilePath.endswith(".ly"), absoluteFilePath
    result = score.lilypond()
    if result:
        with open(absoluteFilePath, "w", encoding="utf-8") as f:
            f.write(result)
        return absoluteFilePath

def saveAsLilypondPDF(score, openPDF = False):
    tempfile = os.path.join(gettempdir(), str(id(score)) + ".ly")
    exportedLilypond = saveAsLilypond(score, tempfile)
    ret = subprocess.call("lilypond --output={} {}".format(exportedLilypond, exportedLilypond), shell=True)  #suffix to output added by lilypond
    if ret == 0 and openPDF:
        subprocess.Popen("xdg-open {}.pdf".format(exportedLilypond), shell=True)

def stringToCharsOnlyString(string):
    def num2word(n):
        """Take a number, return a str.
        Lilypond does not allow numbers in variable names"""
        return ''.join(chr(ord(c)+17) for c in str(n))

    def num2wordForIterations(stringOrNum):
        if stringOrNum in [1,2,3,4,5,6,7,8,9,0] or stringOrNum in "1234567890":
            return num2word(int(stringOrNum))
        elif stringOrNum in ("-", "_"):
            return ""
        else:
            return stringOrNum

    string = string.replace(" ", "_")
    return "".join([num2wordForIterations(c) for c in string])

def lilyfy(string):
    """Escape special lilypond characters like the quote " etc.

    This is extended on a as-needed basis.
    """

    if not string:
        return ""

    if string.startswith("\\markup"):
        return string #trust the user

    string = string.replace('\\n', '\n') #replace the user newline with actual one
    string = string.replace('"', '\\"')
    return string

def fromTemplate(session, data, meta, tempoStaff):
    """Returns a string built from already ly-exported track data and a lilypond template.
    Called by score.lilypond(), which is called by session.lilypond().

    meta is the actual score.metaData dictionary, not a copy. We use this to modify the template
    path entry.

    Laborejo Markers in the template have the syntax %$$DATE$$ .
    That is pretty unique and additionally a lilypondcomment.

    The template file is in metaData["template-file"]. The default is empty string,
    which means we use the programs "default.ly" template.

    For session management reasons this the user template must be a file in the session dir.
    However, a system wide user library of lilypond export templates is very useful and convenient.

    Thus we allow absolute paths as well. Or even relative and ~/ if the user wants. They will be
    converted automatically to a symlink into the session dir and the absolute path will be
    auto-replaced by the local filename to the symlink. (The absolute path will remain in metadata
    and gui field until the file is found. Thus a typo   will not lead to a broken symlink
    creation)

    If template file lookup fails for any reason we use the internal default.ly and log an error
    message.
    """

    #Find and load the template
    templateFile = meta["template-file"]
    try:
        templatePath = findTemplate(session, meta, templateFile)
    except FileNotFoundError: #Fall back to default.py and try again
        logger.error(f"User lilypond template {templateFile} not found. Will use the builtin default.ly instead.")
        templatePath = findTemplate(session, meta, "") #If this fails something is indeed wrong and we let the error raise
    except PermissionError: #Fall back to default.py and try again
        logger.error(f"User lilypond template {templateFile} not readable. Will use the builtin default.ly instead.")
        templatePath = findTemplate(session, meta, "") #If this fails something is indeed wrong and we let the error raise

    #Now we know the templatePath exists and it is either default.ly or a file/link in our session dir.
    with open(templatePath, 'r') as f:
        templateString = f.read()

    templateString = templateString.replace("%$$DATE$$", da.today().strftime("%A %d. %B %Y")) #The current date
    templateString = templateString.replace("%$$GLOBAL-STAFF-SIZE$$", str(meta["global-staff-size"]))
    templateString = templateString.replace("%$$FILENAME$$", session.sessionPrefix)
    templateString = templateString.replace("%$$HEADER$$", processMeta(meta))
    #templateString = templateString.replace("%$$SUBTEXT$$", '"' + lilyfy(meta["subtext"]) + '"')
    templateString = templateString.replace("%$$SUBTEXT$$", lilyfy(meta["subtext"]) )
    voicesString, structureString = processData(data)
    templateString = templateString.replace("%$$VOICES$$", voicesString)
    templateString = templateString.replace("%$$STRUCTURE$$", structureString)
    templateString = templateString.replace("%$$TEMPOSTAFF$$", tempoStaff)
    templateString = templateString.replace("%$$TRANSPOSITION$$", '\\transpose ' + " ".join(meta["transposition"].split())  ) #something like "c' f".  Defaults to "c c ". Lilypond output without ""!

    return templateString

def findTemplate(session, meta, templateFile:str)->str:
    """returns a path. checks for existence and read access through NSMclient functionality.
    This will create a symlink in our session dir and always use this. It will also destructively
    change the user metadata to this symlink file, if present."""

    if not templateFile:
        path = os.path.join(PATHS["share"], "lilypondTemplates", "default.ly")
        return path #we don't need the checks below for our own file

    #User provided a template file name or path

    #Our NSM client can safely import any file. If we try to "import" a file already in our session dir nothing bad will happen, we just use the file.
    assert session.nsmClient.importResource
    logger.info("Trying to use user provided ly template: " + templateFile)

    #This can throw FileNotFoundError or PermissionError, which we catch in the parent function. No need to check for ourselves again here.
    #We get just the filename for symlinks in our session dir. Quickly check that and adjust to absolute path.

    templateFile = os.path.expanduser(templateFile) # ~home

    if os.path.basename(templateFile) == templateFile:
        templateFile = os.path.join(session.sessionPrefix, templateFile)
        #no need to check. even if that fails it will be caught safely below and reported to the log

    path = session.nsmClient.importResource(templateFile) #it will always be an absolute path. Check the nsm INFO log.
    meta["template-file"] = os.path.basename(path)
    logger.info("Imported or re-used: " + path)
    return path


def processData(data):
    """returns two strings. the first actual music data, VOICES, the second the structure and order,
    STRUCTURE"""
    def voice(track, lilypondTrack):
        """ tgliHJuGCFAIICICBEHBJABHIJE= { \key c \major <c'>4 <e'>4 <g'>4 <c''>4 \bar "|."} """
        return "{} = {}".format(stringToCharsOnlyString(track.name), "{ " + lilypondTrack + " }")

    def structure(track, lilypondTrack):
        """ \new Staff = "tgliHJuGCFAIICICBEHBJABHIJE_Staff"  <<  \\new Voice = "tgliHJuGCFAIICICBEHBJABHIJE" \tgliHJuGCFAIICICBEHBJABHIJE  >> %EndTrack """
        name = stringToCharsOnlyString(track.name)
        instruments = '\\with {{ \n instrumentName = #"{}" \n shortInstrumentName = #"{}" }}\n'.format(lilyfy(track.initialInstrumentName), lilyfy(track.initialShortInstrumentName))
        mergeTempo = "\\new Voice = \"Tempo\" \\tempoStaff"
        return  """\\new Staff = "{}_Staff" {} << {} \\new Voice = "{}" \{}  >> %EndTrack""".format(name, instruments, mergeTempo, name, name)

    voices = "\n  ".join(voice(track, lilypondTrack) for track, lilypondTrack in data.items() if lilypondTrack)
    structure = "\n  ".join(structure(track, lilypondTrack) for track, lilypondTrack in data.items() if lilypondTrack)

    return voices, structure


def processMeta(meta):
    """returns a string with lilypond header data like title and composer"""

    def valueMarkup(value):
        value = value.strip()
        if value:
            if value.startswith("\\markup"):
                return value
            else:
                return "\"{}\"".format(value) #results in "value"
        else:
            return "##f"

    #We have more data than lilypond in there. Filter:
    whitelist = ("title", "subtitle", "dedication", "composer", "subsubtitle", "instrument", "meter", "arranger", "poet", "opus", "copyright", "tagline")
    metaString = "\n    ".join(key + " = " + valueMarkup(value) for key, value in meta.items() if key in whitelist)

    return metaString