"""Shared document styles for all Performance West DOCX generators.

Import this module in every generator to ensure consistent typography,
spacing, and formatting across all compliance documents.

Usage:
    from scripts.document_gen.templates._styles import (
        PW, apply_doc_defaults, add_body, add_heading, add_bullets,
        add_signature_block, add_page_numbers, add_horizontal_rule,
    )

All generators should call apply_doc_defaults(doc) first, then use
the helper functions instead of building paragraphs manually.
"""
from __future__ import annotations

import logging
from typing import Optional

LOG = logging.getLogger("document_gen.styles")

try:
    from docx import Document
    from docx.shared import Pt, Inches, RGBColor, Emu
    from docx.enum.text import WD_ALIGN_PARAGRAPH
    from docx.oxml.ns import qn
    from docx.oxml import OxmlElement
except ImportError:
    LOG.warning("python-docx not installed")
    Document = None


# ═══════════════════════════════════════════════════════════════════════════
# Color palette
# ═══════════════════════════════════════════════════════════════════════════

class PW:
    """Performance West brand colors and typography constants."""
    NAVY = RGBColor(0x1A, 0x27, 0x44) if Document else None
    DARK_GRAY = RGBColor(0x37, 0x41, 0x51) if Document else None
    MEDIUM_GRAY = RGBColor(0x6B, 0x72, 0x80) if Document else None
    LIGHT_GRAY = RGBColor(0x9C, 0xA3, 0xAF) if Document else None
    BLACK = RGBColor(0x00, 0x00, 0x00) if Document else None
    GREEN = RGBColor(0x05, 0x96, 0x69) if Document else None
    RED = RGBColor(0xDC, 0x26, 0x26) if Document else None

    # Typography
    FONT_FAMILY = "Calibri"
    BODY_SIZE = Pt(9.5) if Document else None
    BODY_SMALL = Pt(8.5) if Document else None
    HEADING_1_SIZE = Pt(13) if Document else None
    HEADING_2_SIZE = Pt(11) if Document else None
    HEADING_3_SIZE = Pt(10) if Document else None
    TITLE_SIZE = Pt(15) if Document else None
    SUBTITLE_SIZE = Pt(10) if Document else None
    FOOTER_SIZE = Pt(7.5) if Document else None
    SIGNATURE_SIZE = Pt(9.5) if Document else None

    # Spacing
    BODY_AFTER = Pt(8) if Document else None
    HEADING_BEFORE = Pt(16) if Document else None
    HEADING_AFTER = Pt(6) if Document else None
    BULLET_AFTER = Pt(4) if Document else None
    LINE_SPACING = 1.15

    # Margins
    MARGIN_TOP = Inches(0.9) if Document else None
    MARGIN_BOTTOM = Inches(0.9) if Document else None
    MARGIN_LEFT = Inches(1.1) if Document else None
    MARGIN_RIGHT = Inches(1.1) if Document else None


# ═══════════════════════════════════════════════════════════════════════════
# Document setup
# ═══════════════════════════════════════════════════════════════════════════


def apply_doc_defaults(doc, title: str = "", entity_name: str = "") -> None:
    """Apply standard margins, default font, and optional header/footer."""
    for section in doc.sections:
        section.top_margin = PW.MARGIN_TOP
        section.bottom_margin = PW.MARGIN_BOTTOM
        section.left_margin = PW.MARGIN_LEFT
        section.right_margin = PW.MARGIN_RIGHT

    # Set default font on the document's style
    style = doc.styles["Normal"]
    style.font.name = PW.FONT_FAMILY
    style.font.size = PW.BODY_SIZE
    style.font.color.rgb = PW.DARK_GRAY
    style.paragraph_format.space_after = PW.BODY_AFTER
    style.paragraph_format.line_spacing = PW.LINE_SPACING


def add_page_numbers(doc) -> None:
    """Add centered page numbers to the document footer."""
    for section in doc.sections:
        footer = section.footer
        footer.is_linked_to_previous = False
        p = footer.paragraphs[0] if footer.paragraphs else footer.add_paragraph()
        p.alignment = WD_ALIGN_PARAGRAPH.CENTER

        # Page X
        run = p.add_run()
        run.font.size = PW.FOOTER_SIZE
        run.font.color.rgb = PW.LIGHT_GRAY
        run.font.name = PW.FONT_FAMILY

        fc_begin = OxmlElement("w:fldChar")
        fc_begin.set(qn("w:fldCharType"), "begin")
        run._element.append(fc_begin)

        r2 = p.add_run()
        r2.font.size = PW.FOOTER_SIZE
        r2.font.color.rgb = PW.LIGHT_GRAY
        instr = OxmlElement("w:instrText")
        instr.set(qn("xml:space"), "preserve")
        instr.text = " PAGE "
        r2._element.append(instr)

        r3 = p.add_run()
        fc_end = OxmlElement("w:fldChar")
        fc_end.set(qn("w:fldCharType"), "end")
        r3._element.append(fc_end)


def add_pw_footer(doc, entity_name: str = "") -> None:
    """Add 'Prepared by Performance West Inc.' footer with page numbers."""
    for section in doc.sections:
        footer = section.footer
        footer.is_linked_to_previous = False
        p = footer.paragraphs[0] if footer.paragraphs else footer.add_paragraph()
        p.alignment = WD_ALIGN_PARAGRAPH.CENTER

        # "Prepared by Performance West Inc." text
        run = p.add_run("Prepared by Performance West Inc., a regulatory compliance consulting firm")
        run.font.size = PW.FOOTER_SIZE
        run.font.color.rgb = PW.LIGHT_GRAY
        run.font.name = PW.FONT_FAMILY
        run.italic = True

        # Add separator and page number
        sep = p.add_run("  \u2014  Page ")
        sep.font.size = PW.FOOTER_SIZE
        sep.font.color.rgb = PW.LIGHT_GRAY
        sep.font.name = PW.FONT_FAMILY

        # Page number field
        fc_begin = OxmlElement("w:fldChar")
        fc_begin.set(qn("w:fldCharType"), "begin")
        r_page = p.add_run()
        r_page.font.size = PW.FOOTER_SIZE
        r_page.font.color.rgb = PW.LIGHT_GRAY
        r_page._element.append(fc_begin)

        r_instr = p.add_run()
        r_instr.font.size = PW.FOOTER_SIZE
        instr = OxmlElement("w:instrText")
        instr.set(qn("xml:space"), "preserve")
        instr.text = " PAGE "
        r_instr._element.append(instr)

        r_end = p.add_run()
        fc_end = OxmlElement("w:fldChar")
        fc_end.set(qn("w:fldCharType"), "end")
        r_end._element.append(fc_end)


# ═══════════════════════════════════════════════════════════════════════════
# Content helpers
# ═══════════════════════════════════════════════════════════════════════════


def add_title(doc, text: str, subtitle: str = "") -> None:
    """Add a document title (centered, navy, large)."""
    p = doc.add_paragraph()
    p.alignment = WD_ALIGN_PARAGRAPH.CENTER
    p.paragraph_format.space_after = Pt(2)
    run = p.add_run(text)
    run.font.size = PW.TITLE_SIZE
    run.bold = True
    run.font.color.rgb = PW.NAVY
    run.font.name = PW.FONT_FAMILY

    if subtitle:
        p2 = doc.add_paragraph()
        p2.alignment = WD_ALIGN_PARAGRAPH.CENTER
        p2.paragraph_format.space_after = Pt(12)
        run2 = p2.add_run(subtitle)
        run2.font.size = PW.SUBTITLE_SIZE
        run2.italic = True
        run2.font.color.rgb = PW.MEDIUM_GRAY
        run2.font.name = PW.FONT_FAMILY


def add_heading(doc, text: str, level: int = 1) -> None:
    """Add a section heading (navy, bold)."""
    p = doc.add_paragraph()
    size = {1: PW.HEADING_1_SIZE, 2: PW.HEADING_2_SIZE, 3: PW.HEADING_3_SIZE}.get(level, PW.HEADING_2_SIZE)
    before = PW.HEADING_BEFORE if level == 1 else Pt(10)

    p.paragraph_format.space_before = before
    p.paragraph_format.space_after = PW.HEADING_AFTER
    run = p.add_run(text)
    run.bold = True
    run.font.size = size
    run.font.color.rgb = PW.NAVY
    run.font.name = PW.FONT_FAMILY


def add_body(doc, text: str, bold: bool = False, italic: bool = False,
             size=None, color=None, alignment=None) -> None:
    """Add a body paragraph."""
    p = doc.add_paragraph()
    p.paragraph_format.space_after = PW.BODY_AFTER
    p.paragraph_format.line_spacing = PW.LINE_SPACING
    if alignment:
        p.alignment = alignment
    run = p.add_run(text)
    run.font.size = size or PW.BODY_SIZE
    run.font.name = PW.FONT_FAMILY
    run.font.color.rgb = color or PW.DARK_GRAY
    run.bold = bold
    run.italic = italic


def add_field_value(doc, label: str, value: str) -> None:
    """Add a label: value pair on one line."""
    p = doc.add_paragraph()
    p.paragraph_format.space_after = Pt(3)
    p.paragraph_format.line_spacing = PW.LINE_SPACING

    run_label = p.add_run(f"{label}: ")
    run_label.font.size = PW.BODY_SIZE
    run_label.font.name = PW.FONT_FAMILY
    run_label.font.color.rgb = PW.MEDIUM_GRAY
    run_label.bold = False

    run_value = p.add_run(value)
    run_value.font.size = PW.BODY_SIZE
    run_value.font.name = PW.FONT_FAMILY
    run_value.font.color.rgb = PW.DARK_GRAY
    run_value.bold = True


def add_bullets(doc, items: list[str], indent: float = 0.25) -> None:
    """Add a bulleted list."""
    for item in items:
        p = doc.add_paragraph(style="List Bullet")
        p.paragraph_format.left_indent = Inches(indent)
        p.paragraph_format.space_after = PW.BULLET_AFTER
        p.paragraph_format.line_spacing = PW.LINE_SPACING
        p.clear()
        run = p.add_run(item)
        run.font.size = PW.BODY_SIZE
        run.font.name = PW.FONT_FAMILY
        run.font.color.rgb = PW.DARK_GRAY


def add_horizontal_rule(doc) -> None:
    """Add a thin navy horizontal rule."""
    p = doc.add_paragraph()
    p.paragraph_format.space_before = Pt(6)
    p.paragraph_format.space_after = Pt(6)
    pPr = p._p.get_or_add_pPr()
    pBdr = OxmlElement("w:pBdr")
    bottom = OxmlElement("w:bottom")
    bottom.set(qn("w:val"), "single")
    bottom.set(qn("w:sz"), "4")
    bottom.set(qn("w:space"), "1")
    bottom.set(qn("w:color"), "1A2744")
    pBdr.append(bottom)
    pPr.append(pBdr)


def add_signature_block(
    doc,
    signer_name: str = "",
    signer_title: str = "",
    entity_name: str = "",
    date_str: str = "",
    include_perjury: bool = False,
) -> None:
    """Add a standardized signature block."""
    if include_perjury:
        add_body(doc, (
            "I declare under penalty of perjury under the laws of the "
            "United States of America that the foregoing is true and correct."
        ), italic=True, size=PW.BODY_SMALL)

    # Signature line
    add_body(doc, "", size=Pt(20))  # spacer
    p = doc.add_paragraph()
    p.paragraph_format.space_after = Pt(2)
    run = p.add_run("_" * 45)
    run.font.size = PW.SIGNATURE_SIZE
    run.font.name = PW.FONT_FAMILY
    run.font.color.rgb = PW.LIGHT_GRAY

    if signer_name:
        add_body(doc, signer_name, bold=True, size=PW.SIGNATURE_SIZE)
    if signer_title:
        add_body(doc, signer_title, size=PW.BODY_SMALL, color=PW.MEDIUM_GRAY)
    if entity_name:
        add_body(doc, entity_name, size=PW.BODY_SMALL, color=PW.MEDIUM_GRAY)
    if date_str:
        add_body(doc, f"Date: {date_str}", size=PW.BODY_SMALL, color=PW.MEDIUM_GRAY)