"""

@relation(SDOC-SRS-34, SDOC-SRS-141, scope=file)

"""

from typing import Dict, List, Optional, Tuple, Union

from lark import ParseTree, Token, Tree

from strictdoc.backend.sdoc.error_handling import StrictDocSemanticError

from strictdoc.backend.sdoc_source_code.comment_parser.marker_lexer import (

    MarkerLexer,

)

from strictdoc.backend.sdoc_source_code.helpers.comment_preprocessor import (

    preprocess_source_code_comment,

)

from strictdoc.backend.sdoc_source_code.models.language_item_marker import (

    LanguageItemMarker,

)

from strictdoc.backend.sdoc_source_code.models.line_marker import LineMarker

from strictdoc.backend.sdoc_source_code.models.range_marker import (

    RangeMarker,

)

from strictdoc.backend.sdoc_source_code.models.requirement_marker import Req

from strictdoc.backend.sdoc_source_code.models.source_location import ByteRange

from strictdoc.backend.sdoc_source_code.models.source_node import SourceNode

class MarkerParser:

    @staticmethod

    def parse(

        *,

        input_string: str,

        line_start: int,

        line_end: int,

        comment_line_start: int,

        comment_byte_range: Optional[ByteRange],

        filename: Optional[str] = None,

        entity_name: Optional[str] = None,

        col_offset: int = 0,

        custom_tags: Optional[set[str]] = None,

        default_scope: Optional[str] = None,

    ) -> SourceNode:

        """

        Parse source nodes and relation markers from source file comments.

        The input_string is parsed for @relation markers. If custom_tags are given,

        input_string is additionally parsed for source nodes and SourceNode.fields_locations

        offsets are calculated relative to input_string. This implies that input_string

        lines must not be pre-stripped by the caller, otherwise offsets would mismatch with

        actual file content and source node write-back would corrupt source files.

        Comment symbols like /** ... */ or /// Doxygen comments or Python comments

        are instead replaced internally with spaces (preserving string length), so that

        all byte offsets remain valid for both parsing and file write-back.

        The 1-based line start/end provide hints to the parser for the case markers

        of scope file, class or function are found, in which case the user values are

        set as highlight range. If the parser finds line or range markers, the user

        provided line start/end values are ignored. Should be set to the item definition

        block, *with* leading comment lines if any.

        The 1-based comment_line_start parameter is the first actual comment line.

        It is required as a base offset for some parser tokens to determine their

        absolute position in file, as lexing gives only a position relative

        to comment start.

        comment_byte_range, if given, enables write-back of modified source nodes.

        Modification happens when a user edits the source node in the web server, or

        when StrictDoc auto-assigns MID or HASH. Values are 0-based byte-offsets

        specifying the exact input_string start-to-end position inside the source file.

        custom_tags is a set of valid tags if a comment is expected to contain

        key-value pairs for source node generation. The caller is responsible to determine

        valid custom tags from the grammar element associated with the source code file.

        filename should be given if input_string comes from a static source file.

        It will be used to create more helpful parsing error messages.

        entity_name is required for language item markers. It's the user-visible

        description of the marked range in the rendered document. Should be equal

        to the related LanguageItem.description for consistency with forward markers.

        default_scope should be provided if the caller's language-aware parser

        can infer the scope from the semantic comment position. Think of Rust doc

        comments for example. If given, users are allowed to omit the scope argument

        in a relation marker. A user provided scope argument always takes preference.

        If neither default nor a user provided value is available,

        StrictDocSemanticError will be raised.

        The function returns a SourceNode. Note: This is also the case if no custom tags were

        found at all (in which case fields is empty) because SourceNode also acts as a container

        for markers.

        """

        node_fields: Dict[str, str] = {}

        source_node: SourceNode = SourceNode(

            entity_name=entity_name,

            comment_byte_range=comment_byte_range,

        )

        input_string = preprocess_source_code_comment(input_string)

        tree: ParseTree = MarkerLexer.parse(

            input_string, custom_tags=custom_tags

        )

        for element_ in tree.children:

            if not isinstance(element_, Tree):

                continue

            if element_.data == "relation_marker":

                relation_markers = MarkerParser._parse_relation_marker(

                    element_,

                    line_start,

                    line_end,

                    comment_line_start,

                    filename,

                    entity_name,

                    col_offset,

                    default_scope,

                )

                source_node.markers.extend(relation_markers)

            elif element_.data == "node_field":

                node_name, node_value = MarkerParser._parse_node_field(

                    element_,

                )

                node_fields[node_name] = node_value

                source_node.fields_locations[node_name] = (

                    element_.meta.start_pos,

                    element_.meta.end_pos - 1,

                )

            else:

                raise AssertionError

        if len(node_fields) > 0:

            source_node.fields = node_fields

        return source_node

    @staticmethod

    def _parse_relation_marker(

        element_: Tree[Token],

        line_start: int,

        line_end: int,

        comment_line_start: int,

        filename: Optional[str] = None,

        entity_name: Optional[str] = None,

        col_offset: int = 0,

        default_scope: Optional[str] = None,

    ) -> List[Union[LanguageItemMarker, RangeMarker, LineMarker]]:

        markers: List[Union[LanguageItemMarker, RangeMarker, LineMarker]] = []

        relation_uid_elements = []

        relation_scope_element: Optional[Tree[Token]] = None

        relation_role_element: Optional[Tree[Token]] = None

        for relation_marker_element_ in element_.children:

            assert isinstance(relation_marker_element_, Tree)

            if relation_marker_element_.data == "relation_node_uid":

                relation_uid_elements.append(relation_marker_element_)

            elif relation_marker_element_.data == "relation_scope":

                relation_scope_element = relation_marker_element_

            elif relation_marker_element_.data == "relation_role":

                relation_role_element = relation_marker_element_

            else:

                raise NotImplementedError

        assert len(relation_uid_elements) > 0

        if relation_scope_element is not None:

            assert isinstance(relation_scope_element.children[0], Token)

            relation_scope = relation_scope_element.children[0].value

        else:

            relation_scope = default_scope

        relation_role = None

        if relation_role_element is not None:

            assert isinstance(relation_role_element.children[0], Token)

            relation_role = relation_role_element.children[0].value

        requirements = []

        used_uids = set()

        for relation_uid_token_ in relation_uid_elements:

            assert isinstance(relation_uid_token_.children[0], Token)

            assert relation_uid_token_.children[0].line is not None

            relation_uid = relation_uid_token_.children[0].value

            if relation_uid in used_uids:

                raise ValueError(

                    f"@relation marker contains duplicate node UIDs: ['{relation_uid}']. "

                    f"Location: {filename}:{relation_uid_token_.children[0].line}."

                )

            used_uids.add(relation_uid)

            requirement = Req(None, relation_uid)

            requirement.ng_source_line = (

                comment_line_start + relation_uid_token_.children[0].line - 1

            )

            requirement.ng_source_column = relation_uid_token_.children[

                0

            ].column

            requirements.append(requirement)

        if relation_scope in ("file", "class", "function"):

            language_item_marker = LanguageItemMarker(

                None, requirements, scope=relation_scope, role=relation_role

            )

            language_item_marker.ng_source_line_begin = (

                comment_line_start + element_.meta.line - 1

            )

            language_item_marker.ng_source_column_begin = (

                element_.meta.column + col_offset

            )

            language_item_marker.ng_range_line_begin = line_start

            language_item_marker.ng_range_line_end = line_end

            if relation_scope == "file":

                language_item_marker.set_description("entire file")

            elif relation_scope == "function":

                language_item_marker.set_description(

                    f"function {entity_name}()"

                )

            elif relation_scope == "class":

                language_item_marker.set_description(f"class {entity_name}")

            markers.append(language_item_marker)

        elif relation_scope in ("range_start", "range_end"):

            range_marker = RangeMarker(

                None,

                requirements,

                scope=relation_scope,

                role=relation_role,

            )

            range_marker.ng_source_line_begin = (

                comment_line_start + element_.meta.line - 1

            )

            range_marker.ng_source_column_begin = (

                element_.meta.column + col_offset

            )

            range_marker.ng_range_line_begin = (

                comment_line_start + element_.meta.line - 1

            )

            range_marker.ng_range_line_end = (

                comment_line_start + element_.meta.end_line - 1

            )

            markers.append(range_marker)

        elif relation_scope == "line":

            line_marker = LineMarker(None, requirements, role=relation_role)

            line_marker.ng_source_line_begin = (

                comment_line_start + element_.meta.line - 1

            )

            line_marker.ng_source_column_begin = (

                element_.meta.column + col_offset

            )

            line_marker.ng_range_line_begin = (

                comment_line_start + element_.meta.line - 1

            )

            line_marker.ng_range_line_end = (

                comment_line_start + element_.meta.end_line

            )

            markers.append(line_marker)

        elif relation_scope is None:

            reqs = ",".join(sorted(used_uids))

            raise StrictDocSemanticError(

                f"@relation marker for requirements {reqs} misses scope argument.",

                hint="Scope can only be omitted if supported by language, as e.g. with Rust doc comments.",

                example=(

                    "Add a scope argument. Example:\n"

                    f"@relation({reqs}, scope=function)"

                ),

                line=comment_line_start + element_.meta.line - 1,

                filename=filename,

            )

        else:

            raise NotImplementedError

        return markers

    @staticmethod

    def _parse_node_field(

        element_: Tree[Token],

    ) -> Tuple[str, str]:

        node_name_node = element_.children[0]

        assert isinstance(node_name_node, Tree)

        assert node_name_node.data == "node_name"

        assert isinstance(node_name_node.children[0], Token)

        node_name = node_name_node.children[0].value

        node_value_node = element_.children[1]

        assert isinstance(node_value_node, Tree)

        assert node_value_node.data == "node_multiline_value"

        # Find minimal indent in lines 1..n. It will be used to dedent the block.

        dedent = None

        if len(node_value_node.children) > 1:

            for node_value_component_ in node_value_node.children[1:]:

                assert isinstance(node_value_component_, Token)

                if node_value_component_.type == "NEWLINE":

                    continue

                line_value = node_value_component_.value

                non_ws_len = len(line_value.lstrip(" "))

                this_dedent = len(line_value) - non_ws_len

                if dedent is None:

                    dedent = this_dedent

                elif non_ws_len > 0:

                    dedent = min(this_dedent, dedent)

        if dedent is None:

            dedent = 0

        # Join and dedent.

        node_value = ""

        for i, node_value_component_ in enumerate(node_value_node.children):

            assert isinstance(node_value_component_, Token)

            line_value = node_value_component_.value

            if (

                i > 0

                and node_value_component_.type != "NEWLINE"

                and dedent is not None

            ):

                line_value = line_value[min(dedent, len(line_value)) :]

            node_value += line_value

        node_value = node_value.rstrip()

        return node_name, node_value