#!/usr/bin/env python3
#
# Fill in a template with data from fields in an ABC file.
# Fields have any ABC accented characters converted to HTML (default) or Latex.
#
# Rearrange some field contents into display format:
# * In Title fields, change 'sort' form such as 'Exploding Potato, The'
#   to display format 'The Exploding Potato'.
# * In Key fields, translate the ABC key representation to full text,
#   e.g. G#dor becomes G# Dorian.
#
# Recognise continuation header fields and print those too. The ABC standard
# defines continuation fields as starting ':+'. Regrettably none of the tools
# I am using the Booke recognise that syntax, so I am adopting a Booke
# convention of '<header>:+' *also* being a continuation. Note that a
# continuation is a distinct line in the field value; the value has a line
# break between it and the previous line.
#
# Templates are read from file, and are in Python standard library format.
# The following values are substituted:
# * name. The file base name. Base filename without extension.
# * title. The tune title.
# * subtitle. The tune subtitle (second Title field), if any.
# * composer. The tune composer.
# * key. The tune key.
# * changefile. The name of the 'change' file, if any.
# * changename. The change file base name.
# * changetitle. The change file tune title.
# * changevisibility. "yes" if there's a change value, otherwise "no".
# * credit. The 'credit' value.
# * creditvisibility. "yes" if there's a credit value, otherwise "no".
#

import argparse
import pathlib
import string

from abcfield import getFieldDisplayText

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description='Substitute values from ABC file into template.')
    parser.add_argument('-l', '--latex', dest='latex',
                        action='store_true',
                        help='output LaTeX formatted values (default is HTML)')
    parser.add_argument('-t', '--template', dest='template',
                        type=argparse.FileType('r'),
                        required=True,
                        help='template file')
    parser.add_argument('-v', '--value', dest='values', action="append",
                        default=[], help='define var=value items for templater')
    parser.add_argument('input', type=argparse.FileType('r'),
                        help='input ABC file')
    args = parser.parse_args()

    with args.input as f:
        lines = f.readlines()

    input_path = pathlib.Path(args.input.name)

    vars = dict()
    vars["changename"] = ""
    vars["changetitle"] = ""
    vars["changevisibility"] = "no"
    vars["creditvisibility"] = "no"

    vars["name"] = input_path.stem
    vars["title"] = getFieldDisplayText(lines, "T", latex=args.latex)
    vars["subtitle"] = getFieldDisplayText(lines, "T", n=2, latex=args.latex)
    vars["composer"] = getFieldDisplayText(lines, "C", latex=args.latex)
    vars["key"] = getFieldDisplayText(lines, "K", latex=args.latex)
    vars["changefile"] = getFieldDisplayText(lines, "N", starts="Change:", latex=args.latex)
    vars["credit"] = getFieldDisplayText(lines, "N", starts="Credit:", latex=args.latex)

    if vars["changefile"]:
        vars["changevisibility"] = "yes"
        vars["changename"] = pathlib.Path(vars["changefile"]).stem
        cf = pathlib.Path(input_path.parent, vars["changefile"])
        with cf.open() as f:
            vars["changetitle"] = getFieldDisplayText(f, "T", latex=args.latex)

    if vars["credit"]:
        vars["creditvisibility"] = "yes"

    for val in args.values:
        keyval = val.partition("=")
        vars[keyval[0]] = keyval[2]

    print(string.Template(args.template.read()).substitute(vars))