import re
from pathlib import Path

from docx import Document

from tools.doc_generator.logic.core_fields import merge_core_fields
from tools.doc_generator.logic.document_types import get_document_type

BASE_DIR = Path(__file__).resolve().parent.parent
CONTENT_DIR = BASE_DIR / "content"
TEMPLATES_DIR = CONTENT_DIR / "templates"
PROJECT_ROOT = BASE_DIR.parent.parent
EXPORTS_DIR = PROJECT_ROOT / "exports"


def safe_filename(value: str) -> str:
    value = str(value or "document").strip()
    value = re.sub(r"[^A-Za-z0-9._ -]+", "", value)
    value = re.sub(r"\s+", "_", value)
    return value or "document"


def render_filename(pattern: str, data: dict) -> str:
    filename = pattern

    for key, value in data.items():
        filename = filename.replace("{" + key + "}", safe_filename(value))

    return safe_filename(filename)


def replace_placeholders_in_paragraph(paragraph, data: dict):
    full_text = "".join(run.text for run in paragraph.runs)

    new_text = full_text
    for key, value in data.items():
        new_text = new_text.replace("{" + key + "}", "" if value is None else str(value))

    if new_text == full_text:
        return

    for run in paragraph.runs:
        run.text = ""

    if paragraph.runs:
        paragraph.runs[0].text = new_text
    else:
        paragraph.add_run(new_text)


def replace_placeholders_in_table(table, data: dict):
    for row in table.rows:
        for cell in row.cells:
            for paragraph in cell.paragraphs:
                replace_placeholders_in_paragraph(paragraph, data)

            for nested_table in cell.tables:
                replace_placeholders_in_table(nested_table, data)


def generate_docx(document_type_id: str, data: dict) -> Path:
    data = merge_core_fields(data)
    document_type = get_document_type(document_type_id)

    template_path = TEMPLATES_DIR / document_type["template"]

    if not template_path.exists():
        raise FileNotFoundError(f"Template not found: {template_path}")

    EXPORTS_DIR.mkdir(parents=True, exist_ok=True)

    output_pattern = document_type.get("outputFilename", f"{document_type_id}.docx")
    output_filename = render_filename(output_pattern, data)

    if not output_filename.lower().endswith(".docx"):
        output_filename += ".docx"

    output_path = EXPORTS_DIR / output_filename

    document = Document(template_path)

    for paragraph in document.paragraphs:
        replace_placeholders_in_paragraph(paragraph, data)

    for table in document.tables:
        replace_placeholders_in_table(table, data)

    document.save(output_path)

    return output_path