from __future__ import annotations

from db.neo4j_store import Neo4jStore


class BSAGraphBuilder:

    DOCUMENT_ID = "BSA"

    def __init__(self, store: Neo4jStore):
        self.store = store

    # =====================================================
    # NODE PROPS
    # =====================================================

    def _props(self, node_id: str, node_type: str, **kwargs):
        return {
            "id": node_id,
            "document": self.DOCUMENT_ID,
            "node_type": node_type,
            **kwargs
        }

    # =====================================================
    # BUILD ENTRY
    # =====================================================

    def build(self, bsa):

        self._create_document()

        if getattr(bsa, "parts", []):
            self._build_parts(bsa)
        else:
            self._build_chapters(bsa.chapters, self.DOCUMENT_ID)

    # =====================================================
    # DOCUMENT
    # =====================================================

    def _create_document(self):

        self.store.merge_node(
            label="Document",
            node_id=self.DOCUMENT_ID,
            properties=self._props(
                self.DOCUMENT_ID,
                "Document",
                name="Bharatiya Sakshya Adhiniyam, 2023"
            )
        )

    # =====================================================
    # PARTS
    # =====================================================

    def _build_parts(self, bsa):

        for part in bsa.parts:

            part_id = f"BSA-PART-{part.part_no}"

            self.store.merge_node(
                label="Part",
                node_id=part_id,
                properties=self._props(
                    part_id,
                    "Part",
                    part_no=part.part_no,
                    title=part.title,
                    text=part.text
                )
            )

            # child → parent
            self.store.merge_relationship(
                part_id,
                self.DOCUMENT_ID,
                "BELONGS_TO"
            )

            self._build_chapters(part.chapters, part_id)

    # =====================================================
    # CHAPTERS
    # =====================================================

    def _build_chapters(self, chapters, parent_id):

        for chapter in chapters:

            chapter_id = f"BSA-CH-{chapter.chapter_no}"

            self.store.merge_node(
                label="Chapter",
                node_id=chapter_id,
                properties=self._props(
                    chapter_id,
                    "Chapter",
                    chapter_no=chapter.chapter_no,
                    title=chapter.title,
                    text=chapter.text
                )
            )

            self.store.merge_relationship(
                chapter_id,
                parent_id,
                "BELONGS_TO"
            )

            self._build_sections(chapter.sections, chapter_id)

    # =====================================================
    # SECTIONS
    # =====================================================

    def _build_sections(self, sections, parent_id):

        for section in sections:

            section_id = f"BSA-{section.section_no}"

            self.store.merge_node(
                label="Section",
                node_id=section_id,
                properties=self._props(
                    section_id,
                    "Section",
                    section_no=section.section_no,
                    title=section.title,
                    text=section.text
                )
            )

            self.store.merge_relationship(
                section_id,
                parent_id,
                "BELONGS_TO"
            )

            self._build_clauses(section, section_id)
            self._build_explanations(section, section_id)
            self._build_illustrations(section, section_id)
            self._build_references(section, section_id)

    # =====================================================
    # CLAUSES
    # =====================================================

    def _build_clauses(self, section, section_id):

        for clause in getattr(section, "clauses", []):

            clause_id = f"{section_id}({clause.clause_no})"

            self.store.merge_node(
                label="Clause",
                node_id=clause_id,
                properties=self._props(
                    clause_id,
                    "Clause",
                    clause_no=clause.clause_no,
                    text=clause.text
                )
            )

            self.store.merge_relationship(
                clause_id,
                section_id,
                "BELONGS_TO"
            )

            for sub in getattr(clause, "sub_clauses", []):

                sub_id = f"{clause_id}({sub.sub_clause_no})"

                self.store.merge_node(
                    label="SubClause",
                    node_id=sub_id,
                    properties=self._props(
                        sub_id,
                        "SubClause",
                        sub_clause_no=sub.sub_clause_no,
                        text=sub.text
                    )
                )

                self.store.merge_relationship(
                    sub_id,
                    clause_id,
                    "BELONGS_TO"
                )

                for roman in getattr(sub, "roman_clauses", []):

                    roman_id = f"{sub_id}({roman.roman_no})"

                    self.store.merge_node(
                        label="RomanClause",
                        node_id=roman_id,
                        properties=self._props(
                            roman_id,
                            "RomanClause",
                            roman_no=roman.roman_no,
                            text=roman.text
                        )
                    )

                    self.store.merge_relationship(
                        roman_id,
                        sub_id,
                        "BELONGS_TO"
                    )

    # =====================================================
    # EXPLANATIONS
    # =====================================================

    def _build_explanations(self, section, section_id):

        for idx, explanation in enumerate(
            getattr(section, "explanations", []),
            start=1
        ):

            explanation_id = f"{section_id}-EXPL-{idx}"

            self.store.merge_node(
                label="Explanation",
                node_id=explanation_id,
                properties=self._props(
                    explanation_id,
                    "Explanation",
                    text=explanation.text
                )
            )

            self.store.merge_relationship(
                explanation_id,
                section_id,
                "BELONGS_TO"
            )

    # =====================================================
    # ILLUSTRATIONS
    # =====================================================

    def _build_illustrations(self, section, section_id):

        for idx, illustration in enumerate(
            getattr(section, "illustrations", []),
            start=1
        ):

            illustration_id = f"{section_id}-ILL-{idx}"

            self.store.merge_node(
                label="Illustration",
                node_id=illustration_id,
                properties=self._props(
                    illustration_id,
                    "Illustration",
                    text=illustration.text
                )
            )

            self.store.merge_relationship(
                illustration_id,
                section_id,
                "BELONGS_TO"
            )

    # =====================================================
    # REFERENCES (semantic)
    # =====================================================

    def _build_references(self, section, section_id):

        for ref in getattr(section, "references", []):

            target = getattr(ref, "section_no", None)
            if not target:
                continue

            target_id = f"BSA-{target}"

            self.store.merge_relationship(
                section_id,
                target_id,
                "REFERENCES"
            )