import urllib
import urllib2
import json
import random
from urllib2 import URLError
import sys

COMPILER_PATH = "interface/HUTN"

# Bind to the compiler (might have to update path manually!)
sys.path.append(COMPILER_PATH)
from hutn_compiler.compiler import main as do_compile

# Exceptions
class ModelverseException(Exception):
    pass

class UnknownException(ModelverseException):
    pass

class UnknownIdentifier(ModelverseException):
    pass

class UnknownType(ModelverseException):
    pass

class NotAnAssociation(ModelverseException):
    pass

class UnsupportedValue(ModelverseException):
    pass

class CompilationError(ModelverseException):
    pass

class NoSuchAttribute(ModelverseException):
    pass

class UnknownModel(ModelverseException):
    pass

class ConnectionError(ModelverseException):
    pass

class ModelExists(ModelverseException):
    pass

class PermissionDenied(ModelverseException):
    pass

class InvalidMode(ModelverseException):
    pass

class InterfaceMismatch(ModelverseException):
    pass

# Helper functions and configuration: do not use yourself!
taskname = random.random()
address = None
last_output = None
mode = 0

def _input(value):
    # Ugly json encoding of primitives
    if isinstance(value, type([])):
        value = json.dumps(value)
        urllib2.urlopen(urllib2.Request(address, urllib.urlencode({"op": "set_input", "data": value, "taskname": taskname}))).read()
    else:
        value = json.dumps(value)
        #print("Set input: " + str(value))
        urllib2.urlopen(urllib2.Request(address, urllib.urlencode({"op": "set_input", "value": value, "taskname": taskname}))).read()

def _input_raw(value, taskname):
    # Ugly json encoding of primitives
    urllib2.urlopen(urllib2.Request(address, urllib.urlencode({"op": "set_input", "value": value, "taskname": taskname}))).read()

def _compile_AL(code):
    # Compile an action language file and send the compiled code
    code_fragments = code.split("\n")
    code_fragments = [i for i in code_fragments if i.strip() != ""]
    code_fragments = [i.replace("    ", "\t") for i in code_fragments]
    initial_tabs = min([len(i) - len(i.lstrip("\t")) for i in code_fragments])
    code_fragments = [i[initial_tabs:] for i in code_fragments]
    code_fragments.append("")
    code = "\n".join(code_fragments)

    with open("__constraint.alc", "w") as f:
        f.write(code)
        f.flush()

    return do_compile("__constraint.alc", COMPILER_PATH + "/grammars/actionlanguage.g", "CS")

def _compile_model(code):
    # Compile a model and send the compiled graph
    # First change multiple spaces to a tab
    code_fragments = code.split("\n")
    code_fragments = [i for i in code_fragments if i.strip() != ""]
    code_fragments = [i.replace("    ", "\t") for i in code_fragments]
    initial_tabs = min([len(i) - len(i.lstrip("\t")) for i in code_fragments])
    code_fragments = [i[initial_tabs:] for i in code_fragments]
    code_fragments.append("")
    code = "\n".join(code_fragments)

    with open("__model.mvc", "w") as f:
        f.write(code)
        f.flush()

    return do_compile("__model.mvc", COMPILER_PATH + "/grammars/modelling.g", "M") + ["exit"]

def _output(expected=None):
    try:
        global last_output
        last_output = json.loads(urllib2.urlopen(urllib2.Request(address, urllib.urlencode({"op": "get_output", "taskname": taskname}))).read())
        #print("Got output: " + str(last_output))
    except:
        raise UnknownError()
    if expected is not None and last_output != expected:
        raise InterfaceMismatch(_last_output(), expected)
    return last_output

def _last_output():
    return last_output

# Raise common exceptions
def _handle_output(requested=None, split=None):
    value = _output()
    if value.startswith("Model exists: "):
        raise ModelExists()
    elif value.startswith("Permission denied"):
        raise PermissionDenied()
    elif value.startswith("Model not found: "):
        raise UnknownModel()
    elif value.startswith("Element not found: "):
        raise UnknownIdentifier()
    elif value.startswith("Element exists: "):
        raise ElementExists()
    elif value.startswith("Attribute not found: "):
        raise NoSuchAttribute()
    elif requested is not None and value.startswith(requested):
        if split is None:
            return value
        else:
            splitted = value.strip().split(split, 1)
            if len(splitted) == 1:
                return ""
            else:
                return splitted[1].rstrip()
    else:
        raise InterfaceMismatch(value)
    
# Main MvC operations
def init(address_param="http://127.0.0.1:8001"):
    """Starts up the connection to the Modelverse."""
    # return None
    # raises ConnectionError
    # raises UnknownError
    # raises InvalidMode
    global mode
    if mode != 0:
        raise InvalidMode()
    global address
    address = address_param
    try:
        _input_raw('"%s"' % taskname, "task_manager")
        mode = 1
    except URLError as e:
        raise ConnectionError(e.reason)

def login(username, password):
    """Log in a user, if user doesn't exist, it is created."""
    # return None
    # raises UnknownError
    # raises PermissionDenied
    # raises InterfaceMismatch
    global mode
    if mode != 1:
        raise InvalidMode()
    _output("Log on as which user?")
    _input(username)
    if _output() == "Password for existing user?":
        _input(password)
        if _output() == "Welcome to the Model Management Interface v2.0!":
            _output("Use the 'help' command for a list of possible commands")
            _input("quiet")
            mode = 2
        elif _last_output() == "Wrong password!":
            raise PermissionDenied()
        else:
            raise InterfaceMismatch(_last_output())
    elif _last_output() == "This is a new user: please give password!":
        _input(password)
        _output("Please repeat the password")
        _input(password)
        if _output() == "Passwords match!":
            _output("Welcome to the Model Management Interface v2.0!")
            _output("Use the 'help' command for a list of possible commands")
            _input("quiet")
            mode = 2
        elif _last_output() == "Not the same password!":
            # We just sent the same password, so it should be identical, unless the interface changed
            raise InterfaceMismatch(_last_output())
        else:
            raise InterfaceMismatch(_last_output())
    else:
        raise InterfaceMismatch(_last_output())

def model_add(model_name, metamodel_name, model_code=None):
    """Instantiate a new model."""
    # return None
    # raises UnknownModel
    # raises ModelExists
    # raises UnknownError
    # raises PermissionDenied
    # raises CompilationError
    if mode != 2:
        raise InvalidMode()
    # Do this before creating the model, as otherwise compilation errors would make us inconsistent
    if model_code is not None:
        try:
            compiled = _compile_model(model_code)
        except:
            raise CompilationError()
    else:
        compiled = ["exit"]

    _input(["model_add", metamodel_name, model_name])
    _handle_output("Waiting for model constructors...")
    _input(compiled)
    _output("Success")

def model_modify(model_name):
    """Modify an existing model."""
    # return is_write
    # raises UnknownModel
    # raises PermissionDenied
    # raises UnknownError
    global mode
    if mode != 2:
        raise InvalidMode()

    _input(["model_modify", model_name])
    _handle_output("Success")
    # Mode has changed
    mode = 3
    _output("Model loaded, ready for commands!")
    if ("r/w" in _output()):
        write = True
    else:
        write = False
    _output("Use 'help' command for a list of possible commands")
    return write

def model_list():
    """List all models."""
    # return [(model1, metamodel1), (model2, metamodel2), ...]
    # raises UnknownError
    if mode != 2:
        raise InvalidMode()
    _input("model_list")
    output = _handle_output("Success: ", split=" ")
    if output == "":
        return []

    lst = []
    value = output.strip().split("\n")
    for v in value:
        m, mm = v.split(":")
        m = m.strip()
        mm = mm.strip()
        lst.append((m, mm))

    return lst

def model_list_full():
    """List full information on all models."""
    # return [(model1, metamodel1, owner1, group1, permissions1), (model2, metamodel2, owner2, group2, permissions2), ...]
    # raises UnknownError
    if mode != 2:
        raise InvalidMode()
    _input("model_list_full")
    lst = []
    value = _output().strip().split("\n")
    for v in value:
        m, mm = v.split(":")
        m = m.strip()
        mm = mm.strip()
        perm, own, grp, m = m.split(" ")
        lst.append((m, mm, own, grp, perm))

    return lst

def verify(model):
    """Verify if a model conforms to its metamodel."""
    # return "verification_result"
    # raises UnknownError
    # raises UnknownModel
    if mode != 2:
        raise InvalidMode()
    _input(["verify", model])
    return _handle_output("Success: ", split=" ")

def model_overwrite(model_name, new_model=None):
    """Upload a new model and overwrite an existing model."""
    # return None
    # raises UnknownModel
    # raises PermissionDenied
    # raises CompilationError
    # raises UnknownError
    if mode != 2:
        raise InvalidMode()

    if new_model is not None:
        try:
            compiled = _compile_model(new_model)
        except Exception as e:
            raise CompilationError(e)
    else:
        compiled = ["exit"]

    _input(["model_overwrite", model_name])
    _handle_output("Waiting for model constructors...")
    _input(compiled)
    _output("Success")

def user_logout():
    """Log out the current user and break the connection."""
    # return None
    # raises UnknownException
    global mode
    if mode != 2:
        raise InvalidMode()
    _input("exit")
    mode = 0

def user_delete():
    """Removes the current user and break the connection."""
    # return None
    # raises UnknownException
    global mode
    if mode != 2:
        raise InvalidMode()
    _input("self-destruct")
    mode = 0

def model_render(model, mapper):
    """Fetch a rendered verion of a model."""
    # return JSON_representation
    # raises UnknownException
    # raises UnknownIdentifier
    # raises InterfaceMismatch
    global mode
    if mode != 2:
        raise InvalidMode()

    _input(["model_render", model, mapper])
    return _handle_output("Success: ", split=" ")

def transformation_between(source, target):
    global mode
    if mode != 2:
        raise InvalidMode()

    _input(["transformation_between", source, target])
    output = _handle_output("Success: ", split=" ")
    if output == "":
        return []
    lst = [v for v in output.split("\n")]

def transformation_add_MT_language():
    """Create a new Model Transformation language out of a set of metamodels."""
    raise NotImplementedError()

def transformation_add_MT():
    """Create a new model transformation."""
    raise NotImplementedError()

def transformation_add_AL():
    """Create a new action language fragment."""
    raise NotImplementedError()

def transformation_add_MANUAL():
    """Create a new manual model operation."""
    raise NotImplementedError()

def transformation_execute():
    """Execute an existing model operation."""
    raise NotImplementedError()

def transformation_list():
    """List existing model operations."""
    raise NotImplementedError()

def transformation_list_full():
    """List detailed information on model operations."""
    raise NotImplementedError()

def transformation_detail():
    """List full details of a a model operation."""
    raise NotImplementedError()

def transformation_RAMify():
    """Ramify an existing metamodel."""
    raise NotImplementedError()

def process_execute():
    """Execute a process model."""
    raise NotImplementedError()

def permission_modify():
    """Modify permissions of a model."""
    raise NotImplementedError()

def permission_owner():
    """Modify the owning user of a model."""
    raise NotImplementedError()

def permission_group():
    """Modify the owning group of a model."""
    raise NotImplementedError()

def group_create():
    """Create a new group."""
    raise NotImplementedError()

def group_delete():
    """Delete a group of which you are an owner."""
    raise NotImplementedError()

def group_owner_add():
    """Add a new owning user to a group you own."""
    raise NotImplementedError()

def group_owner_delete():
    """Delete an owning user to a group you own."""
    raise NotImplementedError()

def group_join():
    """Add a new user to a group you own."""
    raise NotImplementedError()

def group_kick():
    """Delete a user from a group you own."""
    raise NotImplementedError()

def group_list():
    """List existing groups."""
    raise NotImplementedError()

def admin_promote():
    """Promote a user to admin status."""
    raise NotImplementedError()

def admin_demote():
    """Demote a user from admin status."""
    raise NotImplementedError()

# Actual operations on the model
def element_list(model_name):
    """Return a list of all IDs and the type of the element"""
    # return [(name1, type1), (name2, type2), ...]
    # raises UnknownError
    model_modify(model_name)

    if mode != 3:
        raise InvalidMode()

    try:
        _input("list_full")
        lst = []
        output = _handle_output("Success: ", split=" ")
        if output == "":
            return []
        for v in output.split("\n"):
            m, mm = v.split(":")
            m = m.strip()
            mm = mm.strip()
            lst.append((m, mm))
        return lst

    finally:
        model_exit()

def types(model_name):
    """Return a list of all types usable in the model"""
    # return [type1, type2, ...]
    # raises UnknownError
    model_modify(model_name)

    if mode != 3:
        raise InvalidMode()

    try:
        _input("types")
        lst = []
        output = _handle_output("Success: ", split=" ")
        if output == "":
            return []
        for v in output.split("\n"):
            m, mm = v.split(":")
            m = m.strip()
            lst.append(m)
        return lst

    finally:
        model_exit()

def types_full(model_name):
    """Return a list of full types usable in the model"""
    # return [(type1, typetype1), (type2, typetype2), ...]
    # raises UnknownError
    model_modify(model_name)

    if mode != 3:
        raise InvalidMode()

    try:
        _input("types")
        lst = []
        output = _handle_output("Success: ", split=" ")
        if output == "":
            return []
        for v in output.split("\n"):
            m, mm = v.split(":")
            m = m.strip()
            mm = mm.strip()
            lst.append((m, mm))
        return lst

    finally:
        model_exit()

def read(model_name, ID):
    """Return a tuple of information on the element: its type and source/target (None if not an edge)"""
    # return (type, (source, target))
    # raises UnknownError
    # raises UnknownIdentifier
    model_modify(model_name)

    if mode != 3:
        raise InvalidMode()

    try:
        _input(["read", ID])
        output = _handle_output("Success: ", split=" ")
        v = output.split("\n")
        t = v[1].split(":")[1].strip()
        if (not v[0].startswith("Source:")):
            rval = (t, None)
        else:
            src = v[0].split(":")[1].strip()
            trg = v[1].split(":")[1].strip()
            rval = (t, (src, trg))
        return rval

    finally:
        model_exit()

def read_attrs(model_name, ID):
    """Return a dictionary of attribute value pairs"""
    # return {attr1: value1, attr2: value2, ...}
    # raises UnknownError
    # raises UnknownIdentifier
    model_modify(model_name)

    if mode != 3:
        raise InvalidMode()

    try:
        _input(["read", ID])
        output = _handle_output("Success: ", split=" ")
        v = output.split("\n")
        searching = True
        rval = {}
        for r in v:
            if searching:
                if r == "Attributes:":
                    # Start working on attributes
                    searching = False
            else:
                key, value = r.split(":", 1)
                _, value = value.split("=", 1)
                key = json.loads(key.strip())
                value = value.strip()
                if value == "None":
                    value = None
                elif value == "True":
                    value = True
                elif value == "False":
                    value = False
                else:
                    value = json.loads(value)
                rval[key] = value
        return rval

    finally:
        model_exit()

def instantiate(model_name, typename, edge=None):
    """Create a new instance of the specified typename, between the selected elements (if not None), and with the provided ID (if any)"""
    # return instantiated_ID
    # raises UnknownError
    # raises UnknownType
    # raises UnknownIdentifier
    # raises NotAnEdge
    model_modify(model_name)

    if mode != 3:
        raise InvalidMode()

    try:
        if edge is None:
            _input(["instantiate_node", typename, ""])
        else:
            _input(["instantiate_edge", typename, "", edge[0], edge[1]])
        return _handle_output("Success: ", split=" ")
    finally:
        model_exit()

def delete_element(model_name, ID):
    """Delete the element with the given ID"""
    # return None
    # raises UnknownError
    # raises UnknownIdentifier
    model_modify(model_name)

    if mode != 3:
        raise InvalidMode()

    try:
        _input(["delete", ID])
        _handle_output("Success")
    finally:
        model_exit()

def attr_assign(model_name, ID, attr, value):
    """Assign a value to an attribute"""
    # return None
    # raises UnknownError
    # raises UnknownIdentifier
    # raises NoSuchAttribute
    # raises UnsupportedValue
    model_modify(model_name)

    if mode != 3:
        raise InvalidMode()

    try:
        _input(["attr_add", ID, attr, value])
        _handle_output("Success")
    finally:
        model_exit()

def attr_assign_code(model_name, ID, attr, code):
    """Assign a piece of Action Language code to the attribute"""
    # return None
    # raises UnknownError
    # raises UnknownIdentifier
    # raises NoSuchAttribute
    # raises UnsupportedValue
    try:
        compiled = _compile_AL(code)
    except Exception as e:
        raise CompilationError(e)

    model_modify(model_name)

    if mode != 3:
        raise InvalidMode()

    try:
        _input(["attr_add", ID, attr])
        output = _handle_output("Waiting for code constructors...")
        _input(compiled)
        _output("Success")
    finally:
        model_exit()

def attr_delete(model_name, ID, attr):
    """Remove an attribute."""
    model_modify(model_name)

    if mode != 3:
        raise InvalidMode()

    try:
        _input(["attr_del", ID, attr])
        _handle_output("Success")
    finally:
        model_exit()

def read_outgoing(model_name, ID, typename):
    """Returns a list of all outgoing associations of a specific type ("" = all)"""
    # return [name1, name2, ...]
    # raises UnknownError
    # raises UnknownIdentifier
    model_modify(model_name)

    if mode != 3:
        raise InvalidMode()

    try:
        _input(["read_outgoing", ID, typename])
        output = _handle_output("Success: ", split=" ")
        if output == "":
            return []
        else:
            return output.split("\n")
    finally:
        model_exit()

def read_incoming(model_name, ID, typename):
    """Returns a list of all incoming associations of a specific type ("" = all)"""
    # return [name1, name2, ...]
    # raises UnknownError
    # raises UnknownIdentifier
    # raises UnknownType
    model_modify(model_name)

    if mode != 3:
        raise InvalidMode()

    try:
        _input(["read_incoming", ID, typename])
        output = _handle_output("Success: ", split=" ")
        if output == "":
            return []
        else:
            return output.split("\n")
    finally:
        model_exit()

def read_association_source(model_name, ID):
    """Returns the source of an association."""
    # returns name
    # raises UnknownError
    # raises UnknownIdentifier
    # raises NotAnAssociation
    model_modify(model_name)

    if mode != 3:
        raise InvalidMode()

    try:
        _input(["read_association_source", ID])
        return _handle_output("Success: ", split=" ")
    finally:
        model_exit()

def read_association_destination(model_name, ID):
    """Returns the destination of an association."""
    # returns name
    # raises UnknownError
    # raises UnknownIdentifier
    # raises NotAnAssociation
    model_modify(model_name)

    if mode != 3:
        raise InvalidMode()

    try:
        _input(["read_association_destination", ID])
        return _handle_output("Success: ", split=" ")
    finally:
        model_exit()

def model_exit():
    """Leave model modify mode."""
    # return None
    # raises UnknownError
    global mode
    if mode != 3:
        raise InvalidMode()
    _input("exit")
    _output("Success")
    mode = 2