"""
Utilities for building custom models included in panel.
"""
import fnmatch
import glob
import inspect
import io
import os
import pathlib
import shutil
import tarfile
import zipfile

from concurrent.futures import ThreadPoolExecutor
from functools import cache, partial

import param
import requests

from bokeh.model import Model

from .config import config, panel_extension
from .io.resources import RESOURCE_URLS
from .reactive import ReactiveHTML
from .template.base import BasicTemplate
from .theme import Design

BASE_DIR = pathlib.Path(__file__).parent
BUNDLE_DIR = pathlib.Path(__file__).parent / 'dist' / 'bundled'


@cache
def _session():
    try:
        import platformdirs

        from cachecontrol import CacheControl
        from cachecontrol.caches import SeparateBodyFileCache
        cache_dir = platformdirs.user_cache_path() / 'holoviz' / 'panel.compiler'

        return CacheControl(requests.Session(), cache=SeparateBodyFileCache(cache_dir))
    except ImportError:
        return requests.Session()


def _download(url):
    try:
        response, error = _session().get(url, timeout=10), None
    except Exception:
        try:
            response, error = _session().get(url, verify=False, timeout=10), None
        except Exception as e:
            response, error = None, e
    return response, error

#---------------------------------------------------------------------
# Public API
#---------------------------------------------------------------------

def write_bundled_files(name, files, explicit_dir=None, ext=None, download_list=None):
    if download_list is None:
        _write_bundled_files(name, files, explicit_dir=explicit_dir, ext=ext)
    else:
        download_list.append(partial(_write_bundled_files, name, files, explicit_dir=explicit_dir, ext=ext))

def _write_bundled_files(name, files, explicit_dir=None, ext=None):
    model_name = name.split('.')[-1].lower()
    for bundle_file in files:
        if not bundle_file.startswith('http'):
            dest_path = BUNDLE_DIR / name.lower() / bundle_file
            dest_path.parent.mkdir(parents=True, exist_ok=True)
            shutil.copyfile(BASE_DIR / 'theme' / bundle_file, dest_path)
            continue

        bundle_file = bundle_file.split('?')[0]
        response, error = _download(bundle_file)
        if error:
            msg =  f"Failed to fetch {name} dependency: {bundle_file}. Errored with {error}."
            raise ConnectionError(msg) from error

        map_file = f'{bundle_file}.map'
        map_response, _ = _download(map_file)

        if bundle_file.startswith(config.npm_cdn):
            bundle_path = os.path.join(*bundle_file.replace(config.npm_cdn, '').split('/'))
        else:
            bundle_path = os.path.join(*os.path.join(*bundle_file.split('//')[1:]).split('/')[1:])
        obj_dir = explicit_dir or model_name
        filename = BUNDLE_DIR.joinpath(obj_dir, bundle_path)
        filename.parent.mkdir(parents=True, exist_ok=True)
        filename = str(filename)
        if ext and not str(filename).endswith(ext):
            filename += f'.{ext}'
        if filename.endswith(('.ttf', '.wasm')):
            with open(filename, 'wb') as f:
                f.write(response.content)
        else:
            content = response.content.decode('utf-8')
            with open(filename, 'w', encoding="utf-8") as f:
                f.write(content)
        if map_response:
            with open(f'{filename}.map', 'w', encoding="utf-8") as f:
                f.write(map_response.content.decode('utf-8'))

def write_bundled_tarball(tarball, name=None, module=False, download_list=None):
    if download_list is None:
        _write_bundled_tarball(tarball, name=name, module=module)
    else:
        download_list.append(partial(_write_bundled_tarball, tarball, name=name, module=module))

def _write_bundled_tarball(tarball, name=None, module=False):
    model_name = name.split('.')[-1].lower() if name else ''
    response, error = _download(tarball['tar'])
    if error:
        raise error

    f = io.BytesIO()
    f.write(response.content)
    f.seek(0)
    tar_obj = tarfile.open(fileobj=f)
    exclude = tarball.get('exclude', [])
    for tarf in tar_obj:
        if not tarf.name.startswith(tarball['src']) or not tarf.isfile():
            continue
        path = tarf.name.replace(tarball['src'], '')
        if any(fnmatch.fnmatch(tarf.name, exc) for exc in exclude):
            continue
        bundle_path = os.path.join(*path.split('/'))
        dest_path = tarball['dest'].replace('/', os.path.sep)
        if model_name:
            filename = BUNDLE_DIR.joinpath(model_name, dest_path, bundle_path)
        else:
            filename = BUNDLE_DIR.joinpath(dest_path, bundle_path)
        filename.parent.mkdir(parents=True, exist_ok=True)
        fobj = tar_obj.extractfile(tarf.name)
        filename = str(filename)
        if module and filename.endswith('.js'):
            filename = filename[:-3]
            if filename.endswith('index'):
                filename += '.mjs'
        if any(filename.endswith(ft) for ft in ('.ttf', '.eot', '.woff', '.woff2')):
            content = fobj.read()
            with open(filename, 'wb') as f:
                f.write(content)
        else:
            content = fobj.read().decode('utf-8')
            with open(filename, 'w', encoding="utf-8") as f:
                f.write(content)
    tar_obj.close()

def write_bundled_zip(name, resource, download_list=None):
    if download_list is None:
        _write_bundled_zip(name, resource)
    else:
        download_list.append(partial(_write_bundled_zip, name, resource))

def _write_bundled_zip(name, resource):
    response, error = _download(resource['zip'])
    if error:
        raise error

    f = io.BytesIO()
    f.write(response.content)
    f.seek(0)
    zip_obj = zipfile.ZipFile(f)
    exclude = resource.get('exclude', [])
    for zipf in zip_obj.namelist():
        path = zipf.replace(resource['src'], '')
        if any(fnmatch.fnmatch(zipf, exc) for exc in exclude) or zipf.endswith('/'):
            continue
        bundle_path = path.replace('/', os.path.sep)
        filename = BUNDLE_DIR.joinpath(name, bundle_path)
        filename.parent.mkdir(parents=True, exist_ok=True)
        fdata = zip_obj.read(zipf)
        filename = str(filename)
        if any(filename.endswith(ft) for ft in ('.ttf', '.eot', '.woff', '.woff2')):
            with open(filename, 'wb') as f:
                f.write(fdata)
        else:
            with open(filename, 'w', encoding="utf-8") as f:
                f.write(fdata.decode('utf-8'))
    zip_obj.close()

def write_component_resources(name, component, download_list=None):
    write_bundled_files(name, list(component._resources.get('css', {}).values()), BUNDLE_DIR, 'css', download_list=download_list)
    write_bundled_files(name, list(component._resources.get('js', {}).values()), BUNDLE_DIR, 'js', download_list=download_list)
    js_modules = []
    for tar_name, js_module in component._resources.get('js_modules', {}).items():
        if tar_name not in component._resources.get('tarball', {}):
            js_modules.append(js_module)
    write_bundled_files(name, js_modules, 'js', ext='mjs', download_list=download_list)
    for tarball in component._resources.get('tarball', {}).values():
        write_bundled_tarball(tarball, download_list=download_list)

def bundle_resource_urls(verbose=False, external=True, download_list=None):
    # Collect shared resources
    for name, resource in RESOURCE_URLS.items():
        if verbose:
            print(f'Bundling shared resource {name}.')
        if 'zip' in resource:
            write_bundled_zip(name, resource, download_list=download_list)
        elif 'tar' in resource:
            write_bundled_tarball(resource, name=name, download_list=download_list)

def bundle_templates(verbose=False, external=True, download_list=None):
    # Bundle Template resources
    for name, template in param.concrete_descendents(BasicTemplate).items():
        if verbose:
            print(f'Bundling {name} resources')

        # Bundle Template._resources
        if template._resources.get('bundle', True) and external:
            write_component_resources(name, template, download_list=download_list)

        # Bundle CSS files in template dir
        template_dir = pathlib.Path(inspect.getfile(template)).parent
        dest_dir = BUNDLE_DIR / name.lower()
        dest_dir.mkdir(parents=True, exist_ok=True)
        for css in glob.glob(str(template_dir / '*.css')):
            shutil.copyfile(css, dest_dir / os.path.basename(css))

        # Bundle Template._css
        template_css = template._css
        if not isinstance(template_css, list):
            template_css = [template_css] if template_css else []
        for css in template_css:
            tmpl_name = name.lower()
            for cls in template.__mro__[1:]:
                if not issubclass(cls, BasicTemplate):
                    continue
                tmpl_css = cls._css if isinstance(cls._css, list) else [cls._css]
                if css in tmpl_css:
                    tmpl_name = cls.__name__.lower()
            tmpl_dest_dir = BUNDLE_DIR / tmpl_name
            tmpl_dest_dir.mkdir(parents=True, exist_ok=True)
            shutil.copyfile(css, tmpl_dest_dir / os.path.basename(css))

        # Bundle Template._js
        template_js = template._js
        if not isinstance(template_js, list):
            template_js = [template_js] if template_js else []
        for js in template_js:
            tmpl_name = name.lower()
            for cls in template.__mro__[1:]:
                if not issubclass(cls, BasicTemplate):
                    continue
                tmpl_js = cls._js if isinstance(cls._js, list) else [cls._js]
                if js in tmpl_js:
                    tmpl_name = cls.__name__.lower()
            tmpl_dest_dir = BUNDLE_DIR / tmpl_name
            shutil.copyfile(js, tmpl_dest_dir / os.path.basename(js))

def bundle_themes(verbose=False, external=True, download_list=None):
    # Bundle design stylesheets
    for name, design in param.concrete_descendents(Design).items():
        if verbose:
            print(f'Bundling {name} design resources')

        # Bundle Design._resources
        if design._resources.get('bundle', True) and external:
            write_component_resources(name, design, download_list=download_list)

    theme_bundle_dir = BUNDLE_DIR / 'theme'
    theme_bundle_dir.mkdir(parents=True, exist_ok=True)
    for design_css in glob.glob(str(BASE_DIR / 'theme' / 'css' / '*.css')):
        shutil.copyfile(design_css, theme_bundle_dir / os.path.basename(design_css))

def bundle_models(verbose=False, external=True, download_list=None):
    for imp in panel_extension._imports.values():
        if imp.startswith('panel.models'):
            __import__(imp)

    if not external:
        return

    # Extract Model dependencies
    js_files, css_files, resource_files = {}, {}, {}
    reactive = param.concrete_descendents(ReactiveHTML).values()
    models = (
        list(Model.model_class_reverse_map.items()) +
        [(f'{m.__module__}.{m.__name__}', m) for m in reactive]
    )
    for name, model in models:
        if not name.startswith('panel.'):
            continue
        if verbose:
            print(f'Collecting {name} resources')
        prev_jsfiles = (
            getattr(model, '__javascript_raw__', []) +
            getattr(model, '__javascript_modules_raw__', [])
        ) or None
        prev_jsbundle = getattr(model, '__tarball__', None)
        prev_cls = model
        for cls in model.__mro__[1:]:
            jsfiles = (
                getattr(cls, '__javascript_raw__', []) +
                getattr(cls, '__javascript_modules_raw__', [])
            ) or None
            if ((jsfiles is None and prev_jsfiles is not None) or
                (jsfiles is not None and jsfiles != prev_jsfiles)):
                if prev_jsbundle:
                    js_files[prev_cls.__name__] = prev_jsbundle
                else:
                    js_files[prev_cls.__name__] = prev_jsfiles
                break
            prev_cls = cls
        prev_cssfiles = getattr(model, '__css_raw__', None)
        prev_cls = model
        for cls in model.__mro__[1:]:
            cssfiles = getattr(cls, '__css_raw__', None)
            if ((cssfiles is None and prev_cssfiles is not None) or
                (cssfiles is not None and cssfiles != prev_cssfiles)):
                css_files[prev_cls.__name__] = prev_cssfiles
                break
            prev_cls = cls
        prev_resources = getattr(model, '__resources__', None)
        prev_cls = model
        for cls in model.__mro__[1:]:
            resources = getattr(cls, '__resources__', None)
            if ((resources is None and prev_resources is not None) or
                (resources is not None and resources != prev_resources)):
                resource_files[prev_cls.__name__] = prev_resources
                break
            prev_cls = cls

    # Bundle Model dependencies
    for name, jsfiles in js_files.items():
        if verbose:
            print(f'Bundling {name} model JS resources')
        if isinstance(jsfiles, dict):
            write_bundled_tarball(jsfiles, name=name, download_list=download_list)
        else:
            write_bundled_files(name, jsfiles, download_list=download_list)

    for name, cssfiles in css_files.items():
        if verbose:
            print(f'Bundling {name} model CSS resources')
        write_bundled_files(name, cssfiles, download_list=download_list)

    for name, res_files in resource_files.items():
        write_bundled_files(name, res_files, download_list=download_list)

def bundle_icons(verbose=False, external=True, download_list=None):
    # Bundle icons & images
    dest_dir = BUNDLE_DIR / 'images'
    dest_dir.mkdir(parents=True, exist_ok=True)
    icon_dir = pathlib.Path(__file__).parent.parent / 'doc' / '_static' / 'icons'
    for icon in glob.glob(str(icon_dir / '*')):
        shutil.copyfile(icon, dest_dir / os.path.basename(icon))

def patch_tabulator():
    # https://github.com/olifolkerd/tabulator/issues/4421
    path = BUNDLE_DIR / 'datatabulator' / '[email protected]' / 'dist' / 'js' / 'tabulator.min.js'
    text = path.read_text()
    old = '"focus"!==this.options("editTriggerEvent")&&"click"!==this.options("editTriggerEvent")'
    new = '"click"!==this.options("editTriggerEvent")'
    assert text.count(old) == 1
    text = text.replace(old, new)
    path.write_text(text)

def bundle_resources(verbose=False, external=True):
    download_list = []
    bundle_resource_urls(verbose=verbose, external=external, download_list=download_list)
    bundle_models(verbose=verbose, external=external, download_list=download_list)
    bundle_templates(verbose=verbose, external=external, download_list=download_list)
    bundle_themes(verbose=verbose, external=external, download_list=download_list)
    bundle_icons(verbose=verbose, external=external, download_list=download_list)

    with ThreadPoolExecutor() as executor:
        futures = executor.map(lambda x: x(), download_list)

    # Check for exceptions
    for future in futures:
        if future:
            future.result()

    patch_tabulator()