"""
Convenience functions for translating NWB schema
"""
import pdb
import tempfile
from typing import List, Optional, Dict
from types import ModuleType
from pathlib import Path
import json


import h5py
from linkml_runtime import SchemaView
from linkml_runtime.linkml_model import SchemaDefinition
from linkml_runtime.dumpers import yaml_dumper
from linkml_runtime.utils.compile_python import compile_python



from nwb_schema_language import Namespaces
from nwb_linkml.io import load_schema_file
from nwb_linkml.generators.pydantic import NWBPydanticGenerator
from nwb_linkml.map import apply_preload
from nwb_linkml.adapters import SchemaAdapter, NamespacesAdapter

def make_namespace_adapter(schema: dict) -> NamespacesAdapter:
    """
    Create a :class:`.NamespacesAdapter` from a dictionary of loaded schema + namespace as are commonly
    serialized in nwbfiles under /specifications

    Args:
        schema: 

    Returns:

    """
    namespace = Namespaces(**schema['namespace'])
    schema_adapters = [] # type: List[SchemaAdapter]

    for schema_name, schema_dict in schema.items():
        if schema_name == 'namespace':
            continue
        path = Path(schema_name + '.yaml')
        schema_adapters.append(load_schema_file(path, schema_dict))

    ns_adapter = NamespacesAdapter(
        namespaces=namespace,
        schemas=schema_adapters
    )
    return ns_adapter

def populate_namespaces_imports(namespaces: List[NamespacesAdapter]) -> List[NamespacesAdapter]:
    """
    Given a set of :class:`.NamespacesAdapter`s, populate their imports with the other namespaces, if necessary
    """
    for ns in namespaces:
        needed_imports = []
        for imported_ns in ns.namespaces.namespaces:
            for imported_sch in imported_ns.schema_:
                if imported_sch.namespace and not imported_sch.source:
                    needed_imports.append(imported_sch.namespace)

        # find the import among the namespaces we have
        for other_ns in namespaces:
            if any([imported_ns.name in needed_imports for imported_ns in other_ns.namespaces.namespaces]):
                ns.imported.append(other_ns)
    return namespaces

def translate_namespaces(namespaces: NamespacesAdapter, base_dir: Path) -> List[Path]:
    """
    Write translated namespaces to disk
    """
    built_schemas = namespaces.build().schemas
    base_dir = Path(base_dir)

    paths = []
    for schema in built_schemas:
        output_file = base_dir / (schema.name + '.yaml')
        paths.append(output_file)
        yaml_dumper.dump(schema, output_file)
    return paths

def generate_pydantic(
        namespaces: NamespacesAdapter,
        schema_dir:Optional[Path]=None,
        pydantic_dir:Optional[Path]=None
) -> ModuleType:
    if schema_dir is None:
        temp_schema_dir = tempfile.TemporaryDirectory()
        schema_dir = Path(temp_schema_dir.name)
    if pydantic_dir is None:
        temp_pydantic_dir = tempfile.TemporaryDirectory()
        pydantic_dir = Path(temp_pydantic_dir.name)

    if any(schema_dir.glob('*.yaml')):
        # read already generated schema, do nothing here
        schema_paths = list(schema_dir.glob('*.yaml'))
    else:
        # generate schema files
        schema_paths = translate_namespaces(namespaces, base_dir=schema_dir)

    # just generate the namespace file, which should import everything

    ns_file = [s_path for s_path in schema_paths if s_path.stem == namespaces.namespaces.namespaces[0].name]
    if len(ns_file) == 0:
        raise ValueError("Could not find main namespace file")
    ns_file = ns_file[0]

    generator = NWBPydanticGenerator(
        str(ns_file),
        split=False,
        emit_metadata=True,
        gen_classvars=True,
        gen_slots=True,
        pydantic_version='2'
    )
    serialized = generator.serialize()
    with open(pydantic_dir / 'models.py', 'w') as mfile:
        mfile.write(serialized)
    module = generator.compile_module(pydantic_dir)
    return module

def generate_from_nwbfile(path:Path) -> Dict[str, ModuleType]:
    namespaces = []
    h5f = h5py.File(path, 'r')
    for ns_name, ns in h5f['specifications'].items():
        ns_schema = {}
        for version in ns.values():
            for schema_name, schema in version.items():
                # read the source json binary string
                sch_str = schema[()]
                sch_dict = json.loads(sch_str)
                ns_schema[schema_name] = apply_preload(sch_dict)
        namespaces.append(ns_schema)

    adapters = [make_namespace_adapter(sch) for sch in namespaces]
    adapters = populate_namespaces_imports(adapters)
    pydantic_modules = {
        adapter.namespaces.namespaces[0].name: generate_pydantic(adapter)
        for adapter in adapters
    }
    return pydantic_modules