from .. import util
from .. import resources

from .generic import MeshScript
from ..constants import log

import os
import platform

_search_path = os.environ['PATH']
if platform.system() == 'Windows':
    # try to find Blender install on Windows
    # split existing path by delimiter
    _search_path = [i for i in _search_path.split(';') if len(i) > 0]
    for pf in [r'C:\Program Files',
               r'C:\Program Files (x86)']:
        pf = os.path.join(pf, "Blender Foundation")
        if os.path.exists(pf):
            for p in os.listdir(pf):
                if "Blender" in p:
                    _search_path.append(os.path.join(pf, p))
    _search_path = ';'.join(_search_path)
    log.debug('searching for blender in: %s', _search_path)

if platform.system() == 'Darwin':
    # try to find Blender on Mac OSX
    _search_path = [i for i in _search_path.split(':') if len(i) > 0]
    _search_path.append('/Applications/blender.app/Contents/MacOS')
    _search_path.append('/Applications/Blender.app/Contents/MacOS')
    _search_path.append('/Applications/Blender/blender.app/Contents/MacOS')
    _search_path = ':'.join(_search_path)
    log.debug('searching for blender in: %s', _search_path)

_blender_executable = util.which('blender', path=_search_path)
exists = _blender_executable is not None


def boolean(meshes, operation='difference', debug=False):
    """
    Run a boolean operation with multiple meshes using Blender.
    """
    if not exists:
        raise ValueError('No blender available!')
    operation = str.upper(operation)
    if operation == 'INTERSECTION':
        operation = 'INTERSECT'

    # get the template from our resources folder
    template = resources.get('templates/blender_boolean.py.tmpl')
    script = template.replace('$OPERATION', operation)

    with MeshScript(meshes=meshes,
                    script=script,
                    debug=debug) as blend:
        result = blend.run(_blender_executable +
                           ' --background --python $SCRIPT')

    for m in util.make_sequence(result):
        # blender returns actively incorrect face normals
        m.face_normals = None

    return result


def unwrap(mesh, angle_limit=66, island_margin=0.0, debug=False):
    """
    Run an unwrap operation using blender.
    """
    if not exists:
        raise ValueError('No blender available!')

    # get the template from our resources folder
    template = resources.get('templates/blender_unwrap.py')
    script = template.replace('$ANGLE_LIMIT', "%.6f" % angle_limit
                              ).replace('$ISLAND_MARGIN', "%.6f" % island_margin)

    with MeshScript(meshes=[mesh],
                    script=script,
                    exchange="obj",
                    debug=debug) as blend:
        result = blend.run(_blender_executable +
                           ' --background --python $SCRIPT')

    for m in util.make_sequence(result):
        # blender returns actively incorrect face normals
        m.face_normals = None

    return result