from panflute import Element, ListContainer, Inline, Block
from panflute import Cite, Code, Emph, Image, LineBreak, Link, Math, Note, Quoted, RawInline, SmallCaps, SoftBreak, Space, Span, Str, Strikeout, Strong, Subscript, Superscript, Underline
from panflute import BlockQuote, BulletList, Citation, CodeBlock, Definition, DefinitionItem, DefinitionList, Div, Figure, Header, HorizontalRule, LineBlock, LineItem, ListItem, MetaBlocks, MetaBool, MetaInlines, MetaList, MetaMap, MetaString, Null, OrderedList, Para, Plain, RawBlock, Table, TableBody, TableFoot, TableHead
from panflute import TableRow, TableCell, Caption, Doc
from panflute import MetaValue
from typing import Union, Callable
from types import ModuleType

import os
import re
import warnings
import importlib
import json

from .whitespace import NBSP
from .elements import FQuoted
from .context import Group, InlineGroup, BlockGroup
from .util import nullify, import_md
from .context import Context, CommandCallable
from .whitespace import Whitespace, bavlna
from .command import BlockCommand, InlineCommand, CodeCommand, Command, InlineError
from .command_util import handle_command_define, parse_command
from .nop_processor import NOPProcessor, ELCl, DoubleDocError

class TransformProcessor(NOPProcessor):
	
	root_file_path: str
	root_highlight_style: str = "default"
	_command_modules: list[tuple[Union[dict[str, CommandCallable], ModuleType], str]] = []

	class UnknownElementError(Exception):
		"An unknown Element has been passed to the TransformProcessor, probably because panflute introduced a new one."
		pass

	def __init__(self, root_file_path: str, *args, **kwargs):
		self.root_file_path = root_file_path
		super().__init__(*args, **kwargs)

	def add_command_module(self, module: Union[dict[str, CommandCallable], ModuleType], module_name: str=""):
		self._command_modules.append((module, module_name))

	def get_pretransformers(self) -> list[Callable[[ELCl],ELCl]]:
		return super().get_pretransformers()+[self.handle_if_attribute, self.handle_ifnot_attribute]

	def handle_if_attribute(self, e: ELCl) -> ELCl:
		# `if` attribute. Only show this element if flag is set.
		if hasattr(e, "attributes") and "if" in e.attributes:
			if not self.context.is_flag_set(e.attributes["if"]):
				return nullify(e)
		return e

	def handle_ifnot_attribute(self, e: ELCl) -> ELCl:
		# `ifnot` attribute. Only show this element if flag is NOT set
		if hasattr(e, "attributes") and "ifnot" in e.attributes:
			if self.context.is_flag_set(e.attributes["ifnot"]):
				return nullify(e)
		return e

	def transform_ListContainer(self, e: ListContainer) -> ListContainer:
		try:
			return super().transform_ListContainer(e)
		except TypeError as err:
			names = []
			for el in e:
				if hasattr(el, "attributes") and "c" in el.attributes:
					names.append(el.attributes["c"])
			if len(names) > 0:
				raise InlineError(f"The command{'s' if len(names) > 1 else ''} {names[0] if len(names) == 1 else names} was called in an Inline way but returned Block content. Put it in a paragraph alone or execute it as a Div using: \n::: {{c={names[0] if len(names) == 1 else '<command_name>'}}}\n:::")
			else:
				raise err

	def transform_Doc(self, e: Doc) -> Doc:
		if self.context is not None:
			raise DoubleDocError()
		self.context = Context(e, self.root_file_path)
		for module, module_name in self._command_modules:
			self.context.add_commands_from_module(module, module_name)
		e.content = self.transform(e.content)
		e.content = [BlockGroup(*e.content, context=self.context)]
		return e


	def transform_Quoted(self, e: Quoted) -> FQuoted:
		e.content = self.transform(e.content)
		quote_styles = {
			"cs": "cs",
			"en": "en",
			"sk": "cs",
			None: None
		}
		return FQuoted(*e.content, quote_type=e.quote_type, style=quote_styles[self.context.get_metadata("lang")])

	def transform_Image(self, e: Image) -> Image:
		e.content = self.transform(e.content)
		# OG now has Context so this is not needed per se, but I'm keeping this here for the handling of attribute > context > default value
		# Pass down "no-srcset" metadatum as attribute down to images.
		if not "no-srcset" in e.attributes:
			e.attributes["no-srcset"] = self.context.get_metadata("no-srcset") if self.context.get_metadata("no-srcset") is not None else False
		return e

	def create_Group(self, *content, new_context: Context, inline: bool=False) -> Group:
		old_context = self.context
		self.context = new_context
		content = self.transform([*content])
		self.context = old_context
		if inline:
			return InlineGroup(*content, context=new_context)
		else:
			return BlockGroup(*content, context=new_context)

	def transform_Para(self, e: Para) -> Union[Para, Div]:
		if len(e.content) == 1 and isinstance(e.content[0], Span):
			# If the span turns out to be a command, it might return a Div. We should then replace ourselves with the Div
			span = e.content[0]
			span = self.transform(span)
			if isinstance(span, Div):
				return span
			else:
				e.content[0] = span
				return super().transform_Para(e)
		else:
			return super().transform_Para(e)

	def transform_Div(self, e: Div) -> Union[Div, Group, Null, RawBlock]:
		e.content = self.transform(e.content)

		if "group" in e.classes:
			# `.group` class for Divs
			# Content of Div is enclosed in a separate context, all attributes are passed as metadata
			new_context = Context(Doc(), self.context.path, self.context, trusted=self.context.trusted)
			for attribute, value in e.attributes.items():
				new_context.set_metadata(attribute, value)
			return self.create_Group(*e.content, new_context=new_context)

		if "c" in e.attributes:
			# Commands can be called multiple ways, this handles the following syntax:
			# :::{c=commandname}
			# :::
			e = BlockCommand(*e.content, identifier=e.identifier, classes=e.classes, attributes=e.attributes)
			return self.transform(e)

		if "partial" in e.attributes:
			# `partial` attribute
			# Used to include a file which is executed in a different (child) Context.
			if not "type" in e.attributes:
				e.attributes["type"] = "md"
			if not self.context.trusted: # If we're in an untrusted context, we shouldn't allow inclusion of files outside the PWD.
				full_path = os.path.abspath(self.context.dir + "/" + e.attributes["partial"])
				pwd = os.path.abspath(".")
				if os.path.commonpath([full_path, pwd]) != os.path.commonpath([pwd]):
					return nullify(e)
			text = open(self.context.dir + "/" + e.attributes["partial"], "r").read()
			path = self.context.dir + "/" + e.attributes["partial"]
			if e.attributes["type"] == "md":
				includedDoc = import_md(text)
				trusted = True
				if "untrusted" in e.attributes and (e.attributes["untrusted"] == True or e.attributes["untrusted"] == 'True'):
					trusted = False
				if not self.context.trusted:
					trusted = False
				return self.create_Group(*includedDoc.content, new_context=Context(includedDoc, path, self.context, trusted=trusted))
			elif e.attributes["type"] in ["tex", "html"]:
				return RawBlock(text, e.attributes["type"])

		if "header_content" in e.classes:
			header_content = self.context.get_metadata("header_content")
			header_content = [] if header_content is None else header_content
			header_content.append(MetaBlocks(*self.transform(e.content)))
			self.context.set_metadata("header_content", header_content)
			return Null()

		if "footer_content" in e.classes:
			footer_content = self.context.get_metadata("footer_content")
			footer_content = [] if footer_content is None else footer_content
			footer_content.append(MetaBlocks(*self.transform(e.content)))
			self.context.set_metadata("footer_content", footer_content)
			return Null()

		if "lang" in e.attributes:
			warnings.warn("To set language in a way formátítko will understand, this Div has to have the `.group` class and be a Group.", UserWarning)

		return e

	def transform_Span(self, e: Span) -> Span:
		e.content = self.transform(e.content)

		if "group" in e.classes:
			# `.group` class for Spans
			# Content of Span is enclosed in a separate context, all attributes are passed as metadata
			new_context = Context(Doc(), self.context.path, self.context, trusted=self.context.trusted)
			for attribute, value in e.attributes.items():
				new_context.set_metadata(attribute, value)
			return self.create_Group(*e.content, new_context=new_context, inline=True)

		if "c" in e.attributes:
			# Commands can be called multiple ways, this handles the following syntax:
			# []{c=commandname} and
			e = InlineCommand(*e.content, identifier=e.identifier, classes=e.classes, attributes=e.attributes)
			return self.transform(e)

		if len(e.content) == 1 and isinstance(e.content[0], Str):
			## Handle special command shorthand [!commandname]{}
			if re.match(r"^![\w.]+$", e.content[0].text):
				e = InlineCommand(identifier=e.identifier, classes=e.classes, attributes={**e.attributes, "c": e.content[0].text[1:]})
				return self.transform(e)

			## Handle import [#ksp_formatitko as ksp]{}, [#ksp_formatitko]{type=module} or [#path/file.md]{type=md}
			# Import a python module as commands (type=module, the default) or
			# import all metadata from a md file, dropping its contents.
			elif re.match(r"^#.+$", e.content[0].text):
				if not "type" in e.attributes:
					e.attributes["type"] = "module"
				if e.attributes["type"] == "md":
					importedDoc = import_md(open(self.context.dir + "/" + e.content[0].text[1:], "r").read())
					self.transform(importedDoc.content)
				elif e.attributes["type"] == "module":
					matches = re.match(r"^(\w+)(?: as (\w+))?$", e.content[0].text[1:])
					if not matches:
						raise SyntaxError(f"`{e.content[0].text[1:]}`: invalid syntax")
					module = importlib.import_module(matches.group(1))
					module_name = matches.group(1) if matches.group(2) is None else matches.group(2)
					self.context.add_commands_from_module(module, module_name)
				elif e.attributes["type"] == "metadata":
					data = json.load(open(self.context.dir + "/" + e.content[0].text[1:], "r"))
					key = "" if not "key" in e.attributes else e.attributes["key"]
					self.context.import_metadata(data, key)
				else:
					raise SyntaxError(f"`{e.attributes['type']}`: invalid import type")

				return nullify(e)

			## Handle metadata print [$key1.key2]{}
			# This is a shorthand for just printing the content of some metadata.
			elif re.match(r"^\$[\w.]+$", e.content[0].text):
				val = self.context.get_metadata(e.content[0].text[1:], False)
				if isinstance(val, MetaInlines):
					e = Span(*val.content)
					e = self.transform(e)
				elif isinstance(val, MetaString):
					e = Span(Str(val.string))
				elif isinstance(val, MetaBool):
					e = Span(Str(str(val.boolean)))
				else:
					raise TypeError(f"Cannot print value of metadatum '{e.content[0].text[1:]}' of type '{type(val)}'")
				return e

		return e

	def transform_CodeBlock(self, e: CodeBlock) -> Union[CodeBlock, Div, Null]:
		if "markdown" in e.classes and "group" in e.classes:
			includedDoc = import_md(e.text)
			return self.create_Group(*includedDoc.content, new_context=Context(includedDoc, self.context.path, self.context, self.context.trusted))

		if "python" in e.classes and "run" in e.classes:
			if not self.context.trusted:
				return nullify(e)
			command_output = parse_command(e.text)(BlockCommand(), self.context, self)
			e = BlockCommand().replaceSelf(*([] if command_output is None else command_output))
			return self.transform(e)

		if "python" in e.classes and ("define" in e.attributes or "redefine" in e.attributes):
			if not self.context.trusted:
				return nullify(e)
			return handle_command_define(e, self.context)

		if "c" in e.attributes:
			return self.transform(CodeCommand(e.text, identifier=e.identifier, classes=e.classes, attributes=e.attributes))

		# Pass down metadata 'highlight' and 'highlight_style' as attribute to CodeBlocks
		# OG now has Context so this is not needed per se, but I'm keeping this here for the handling of attribute > context > default value
		if not "highlight" in e.attributes:
			e.attributes["highlight"] = self.context.get_metadata("highlight") if self.context.get_metadata("highlight") is not None else True
		if not "style" in e.attributes:
			e.attributes["style"] = self.context.get_metadata("highlight-style") if self.context.get_metadata("highlight-style") is not None else "default"
		return e

	def transform_Command(self, e: Command) -> Union[Div, Span]:
		if not self.context.get_command(e.attributes["c"]):
			raise NameError(f"Command not defined '{e.attributes['c']}'.")
		command_output = self.context.get_command(e.attributes["c"])(e, self.context, self)
		e = e.replaceSelf(*([] if command_output is None else command_output))
		return e

	def transform_Whitespace(self, e: Whitespace) -> Whitespace:
		if bavlna(e, self.context):
			return NBSP()
		else:
			return e