#!/usr/bin/env python3
"""Build the Cloud Drift pandoc reference.docx from pandoc's default reference doc."""
import copy
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

SRC = "pandoc-default-reference.docx"
OUT = "clouddrift-reference.docx"
LOGO = "clouddrift-logo.png"

FIRE_OPAL = RGBColor(0xE4, 0x52, 0x49)
WHITE_COFFEE = RGBColor(0xE8, 0xDC, 0xD0)
RAISIN = RGBColor(0x25, 0x25, 0x25)
MUTED = RGBColor(0x59, 0x59, 0x59)

LIGHT = "Open Sans Light"
REGULAR = "Open Sans"


def strip_theme_attrs(rpr_or_font_element):
    """Remove theme-based color/font attrs so explicit values always win."""
    if rpr_or_font_element is None:
        return
    for tag in ("color",):
        el = rpr_or_font_element.find(qn(f"w:{tag}"))
        if el is not None:
            for attr in ("themeColor", "themeTint", "themeShade"):
                if el.get(qn(f"w:{attr}")) is not None:
                    del el.attrib[qn(f"w:{attr}")]
    rfonts = rpr_or_font_element.find(qn("w:rFonts"))
    if rfonts is not None:
        for attr in ("asciiTheme", "hAnsiTheme", "eastAsiaTheme", "cstheme"):
            if rfonts.get(qn(f"w:{attr}")) is not None:
                del rfonts.attrib[qn(f"w:{attr}")]


def set_style(doc, name, font_name=None, size=None, color=None, bold=None, italic=None):
    style = doc.styles[name]
    f = style.font
    if font_name:
        f.name = font_name
        rpr = style.element.get_or_add_rPr()
        rfonts = rpr.find(qn("w:rFonts"))
        if rfonts is None:
            rfonts = OxmlElement("w:rFonts")
            rpr.append(rfonts)
        rfonts.set(qn("w:ascii"), font_name)
        rfonts.set(qn("w:hAnsi"), font_name)
        rfonts.set(qn("w:cs"), font_name)
        rfonts.set(qn("w:eastAsia"), font_name)
    if size:
        f.size = Pt(size)
    if color:
        f.color.rgb = color
    if bold is not None:
        f.bold = bold
    if italic is not None:
        f.italic = italic
    strip_theme_attrs(style.element.get_or_add_rPr())


def disable_keep_with_next(doc, names):
    """Remove keepNext/keepLines from these styles' pPr.

    Pandoc's default reference doc sets keepNext+keepLines on every Heading
    style (standard Word behavior: never orphan a heading alone at the
    bottom of a page). But when the very next block is a large table, this
    can backfire badly under some renderers (observed in Pages): the
    heading gets stranded alone on a page and the entire table is pushed to
    the following page, leaving a mostly-blank page in between. Dropping
    keepNext/keepLines lets pagination flow naturally instead - worst case
    a heading ends up as the last line on a page, which is a far smaller
    cosmetic cost than a near-empty page.
    """
    for name in names:
        style = doc.styles[name]
        pPr = style.element.get_or_add_pPr()
        for tag in ("w:keepNext", "w:keepLines"):
            el = pPr.find(qn(tag))
            if el is not None:
                pPr.remove(el)


def add_field(paragraph, field_code):
    run = paragraph.add_run()
    r = run._r
    fld_begin = OxmlElement("w:fldChar")
    fld_begin.set(qn("w:fldCharType"), "begin")
    instr = OxmlElement("w:instrText")
    instr.set(qn("xml:space"), "preserve")
    instr.text = f" {field_code} "
    fld_sep = OxmlElement("w:fldChar")
    fld_sep.set(qn("w:fldCharType"), "separate")
    fld_end = OxmlElement("w:fldChar")
    fld_end.set(qn("w:fldCharType"), "end")
    r.append(fld_begin)
    r2 = paragraph.add_run()._r
    r2.append(instr)
    r3 = paragraph.add_run()._r
    r3.append(fld_sep)
    r4 = paragraph.add_run()._r
    r4.append(fld_end)


def main():
    doc = Document(SRC)

    # --- Base body text ---
    set_style(doc, "Normal", LIGHT, 11, RAISIN)
    set_style(doc, "Body Text", LIGHT, 11, RAISIN)
    set_style(doc, "Compact", LIGHT, 11, RAISIN)
    set_style(doc, "First Paragraph", LIGHT, 11, RAISIN)
    set_style(doc, "Default Paragraph Font", LIGHT, 11, RAISIN)

    # --- Title / subtitle ---
    set_style(doc, "Title", LIGHT, 30, FIRE_OPAL, bold=False)
    doc.styles["Title"].paragraph_format.space_after = Pt(4)
    set_style(doc, "Subtitle", LIGHT, 14, MUTED, bold=False, italic=False)

    # --- Headings ---
    set_style(doc, "Heading 1", LIGHT, 22, RAISIN, bold=False)
    doc.styles["Heading 1"].paragraph_format.space_before = Pt(20)
    doc.styles["Heading 1"].paragraph_format.space_after = Pt(8)

    set_style(doc, "Heading 2", REGULAR, 16, FIRE_OPAL, bold=True)
    doc.styles["Heading 2"].paragraph_format.space_before = Pt(16)
    doc.styles["Heading 2"].paragraph_format.space_after = Pt(6)

    set_style(doc, "Heading 3", REGULAR, 13, RAISIN, bold=True)
    doc.styles["Heading 3"].paragraph_format.space_before = Pt(12)

    for lvl, sz in ((4, 11.5), (5, 11), (6, 11)):
        name = f"Heading {lvl}"
        set_style(doc, name, REGULAR, sz, MUTED, bold=True, italic=(lvl == 6))

    # Avoid huge empty-page gaps when a heading is immediately followed by
    # a large table (see disable_keep_with_next docstring).
    disable_keep_with_next(doc, [f"Heading {n}" for n in range(1, 10)])

    # --- Quotes / block text ---
    set_style(doc, "Block Text", LIGHT, 11, MUTED, italic=True)
    bt_pPr = doc.styles["Block Text"].element.get_or_add_pPr()
    pbdr = OxmlElement("w:pBdr")
    left = OxmlElement("w:left")
    left.set(qn("w:val"), "single")
    left.set(qn("w:sz"), "18")
    left.set(qn("w:space"), "8")
    left.set(qn("w:color"), "E45249")
    pbdr.append(left)
    bt_pPr.append(pbdr)

    # --- Hyperlinks ---
    set_style(doc, "Hyperlink", LIGHT, None, FIRE_OPAL)
    hl_rpr = doc.styles["Hyperlink"].element.get_or_add_rPr()
    u = OxmlElement("w:u")
    u.set(qn("w:val"), "single")
    hl_rpr.append(u)

    # --- Table: shaded header row, light borders ---
    table_style = doc.styles["Table"]
    tbl_pr = table_style.element.find(qn("w:tblPr"))
    if tbl_pr is None:
        tbl_pr = OxmlElement("w:tblPr")
        table_style.element.append(tbl_pr)
    borders = OxmlElement("w:tblBorders")
    for edge in ("top", "left", "bottom", "right", "insideH", "insideV"):
        el = OxmlElement(f"w:{edge}")
        el.set(qn("w:val"), "single")
        el.set(qn("w:sz"), "4")
        el.set(qn("w:space"), "0")
        el.set(qn("w:color"), "E8DCD0")
        borders.append(el)
    tbl_pr.append(borders)

    style_pr = table_style.element.find(qn("w:tblStylePr"))
    if style_pr is None:
        style_pr = OxmlElement("w:tblStylePr")
        style_pr.set(qn("w:type"), "firstRow")
        table_style.element.append(style_pr)
    tc_pr = style_pr.find(qn("w:tcPr"))
    if tc_pr is None:
        tc_pr = OxmlElement("w:tcPr")
        style_pr.append(tc_pr)
    shd = OxmlElement("w:shd")
    shd.set(qn("w:val"), "clear")
    shd.set(qn("w:color"), "auto")
    shd.set(qn("w:fill"), "E8DCD0")
    tc_pr.append(shd)
    rpr_fr = style_pr.find(qn("w:rPr"))
    if rpr_fr is None:
        rpr_fr = OxmlElement("w:rPr")
        style_pr.append(rpr_fr)
    b_el = OxmlElement("w:b")
    rpr_fr.append(b_el)
    color_el = OxmlElement("w:color")
    color_el.set(qn("w:val"), "252525")
    rpr_fr.append(color_el)

    # --- Verbatim / code ---
    try:
        set_style(doc, "Verbatim Char", None, 10, RAISIN)
    except KeyError:
        pass

    # --- Page setup: A4, 1 inch margins ---
    section = doc.sections[0]
    section.page_width = Inches(8.27)
    section.page_height = Inches(11.69)
    section.left_margin = Inches(1)
    section.right_margin = Inches(1)
    section.top_margin = Inches(1)
    section.bottom_margin = Inches(1)
    section.header_distance = Inches(0.4)
    section.footer_distance = Inches(0.4)

    # --- Header: Cloud Drift logo ---
    header = section.header
    header.is_linked_to_previous = False
    hp = header.paragraphs[0]
    hp.text = ""
    hp.alignment = WD_ALIGN_PARAGRAPH.LEFT
    run = hp.add_run()
    run.add_picture(LOGO, width=Inches(0.85))

    # --- Footer: page number, right aligned, muted ---
    footer = section.footer
    footer.is_linked_to_previous = False
    fp = footer.paragraphs[0]
    fp.text = ""
    fp.alignment = WD_ALIGN_PARAGRAPH.RIGHT
    run = fp.add_run("Page ")
    run.font.name = REGULAR
    run.font.size = Pt(9)
    run.font.color.rgb = MUTED
    add_field(fp, "PAGE")
    run2 = fp.add_run(" of ")
    run2.font.name = REGULAR
    run2.font.size = Pt(9)
    run2.font.color.rgb = MUTED
    add_field(fp, "NUMPAGES")

    doc.save(OUT)
    print("Saved", OUT)


if __name__ == "__main__":
    main()