#!/usr/bin/env python

import sys
import argparse
import logging

from ppci.c3 import Builder
import ppci
from ppci.irutils import Verifier, Writer
from ppci.codegen import CodeGenerator
import outstream
from utils import HexFile
import target
from ppci import irutils
import io


logformat='%(asctime)s|%(levelname)s|%(name)s|%(message)s'


def logLevel(s):
    """ Converts a string to a valid logging level """
    numeric_level = getattr(logging, s.upper(), None)
    if not isinstance(numeric_level, int):
        raise ValueError('Invalid log level: {}'.format(s))
    return numeric_level


class RstFormatter(logging.Formatter):
    """ Formatter that tries to create an rst document """
    def __init__(self):
        super().__init__(fmt=logformat)

    def format(self, record):
        s = super().format(record)
        if hasattr(record, 'ircode'):
            f = io.StringIO()
            print('', file=f)
            print('', file=f)
            print('.. code::', file=f)
            print('', file=f)
            Writer('  ').write(record.ircode, f)
            print('', file=f)
            s += '\n' + f.getvalue()
        if hasattr(record, 'irfunc'):
            f = io.StringIO()
            print('', file=f)
            print('', file=f)
            print('.. code::', file=f)
            print('', file=f)
            Writer('  ').write_function(record.irfunc, f)
            print('', file=f)
            s += '\n' + f.getvalue()
        if hasattr(record, 'ppci_frame'):
            f = io.StringIO()
            frame = record.ppci_frame
            print('', file=f)
            print('.. code::', file=f)
            print('', file=f)
            print('  {}'.format(frame.name), file=f)
            for i in frame.instructions:
                print('   {}'.format(i),file=f)
            print('', file=f)
            s += '\n' + f.getvalue()
        if hasattr(record, 'ra_cfg'):
            f = io.StringIO()
            print('', file=f)
            print('', file=f)
            print('.. graphviz::', file=f)
            print('', file=f)
            print('  digraph G {', file=f)
            cfg = record.ra_cfg
            cfg.to_dot(f)
            print('  }', file=f)
            print('', file=f)
            s += '\n' + f.getvalue()
        return s


target_list = [target.armtarget]
targets = {t.name: t for t in target_list}
targetnames = list(targets.keys())

# Parse arguments:
parser = argparse.ArgumentParser(description='lcfos Compiler')
# Input:
parser.add_argument('source', type=argparse.FileType('r'), \
  help='the source file to build', nargs="+")
parser.add_argument('-i', '--imp', type=argparse.FileType('r'), \
  help='Possible import module', action='append', default=[])

parser.add_argument('--dumpir', action='store_true', help="Dump IR-code")
parser.add_argument('--dumpasm', action='store_true', help="Dump ASM-code")
parser.add_argument('--optimize', action='store_true', help="Optimize")
parser.add_argument('--target', help="Backend selection",
    choices=targetnames, required=True)
parser.add_argument('-o', '--output', help='Output file', metavar='filename')
parser.add_argument('--hexfile', help='Output hexfile',
    type=argparse.FileType('w'))
parser.add_argument('--log', help='Log level (INFO,DEBUG)', type=logLevel)


def zcc(srcs, imps, tg, outs, diag, dumpir=False):
    """
        Compile sources into output stream.
        Sources is an iterable of open files.
    """
    logging.info('Zcc started')
    # Front end:
    c3b = Builder(diag, tg)
    cg = CodeGenerator(tg)

    # TODO: remove this arm specifics:
    outs.getSection('code').address = 0x08000000
    outs.getSection('data').address = 0x20000000

    # Emit some custom start code:
    tg.startCode(outs)
    for ircode in c3b.build(srcs, imps):
        if not ircode:
            return
        # Optimization passes, TODO
        Verifier().verify(ircode)

        if dumpir:
            f = io.StringIO()
            irutils.Writer().write(ircode, f)
            print(f.getvalue())

        # Code generation:
        d = {'ircode':ircode}
        logging.info('Starting code generation for {}'.format(ircode), extra=d)
        cg.generate(ircode, outs)
    # TODO: fixup references, do this in another way?
    outs.backpatch()
    outs.backpatch()  # Why two times?
    return c3b.ok


def main(args):
    logging.basicConfig(format=logformat, level=args.log)
    #logging.getLogger().addHandler(RstLogHandler())
    fh = logging.FileHandler('log.rst', mode='w')
    fh.setFormatter(RstFormatter())
    logging.getLogger().addHandler(fh)

    tg = targets[args.target]
    diag = ppci.DiagnosticsManager()
    outs = outstream.TextOutputStream()

    res = zcc(args.source, args.imp, tg, outs, diag, dumpir=args.dumpir)
    if not res:
        diag.printErrors()
        return 1

    if args.dumpasm:
        outs.dump()

    code_bytes = outs.sections['code'].to_bytes()
    if args.output:
        output_filename = args.output
        with open(output_filename, 'wb') as f:
            f.write(code_bytes)

    if args.hexfile:
        logging.info('Creating hexfile')
        hf = HexFile()
        hf.addRegion(0x08000000, code_bytes)
        hf.save(args.hexfile)
    return 0


if __name__ == '__main__':
    arguments = parser.parse_args()
    sys.exit(main(arguments))