#!/usr/bin/env python3
"""Render bible.json into one semantic HTML fragment per book.

Reads the JSON produced by extract_bible.py and writes books/GEN.html and so
on, plus an index. These are fragments, not documents: a <title> and one root
element carrying data-template. The document around them is assembled from the
nunjucks templates in assets/templates/ -- by the service worker, or by
boot.html when there can never be one -- so chrome changes never require
running this. The markup
carries structure and no presentation: every USFM distinction survives as a
class or data attribute, so the whole corpus can be restyled from the
stylesheet without regenerating it.

This is the only build step left, and books/ is all it owns: everything
hand-written lives in assets/ and is served straight from there. Run it when
bible.json changes, which is to say almost never.

Grouping worth knowing about: consecutive poetry lines are wrapped in a
<div class="poetry"> that a blank-line block closes, so stanzas are real
elements rather than spacing; consecutive list items become one <ul>.
"""

from __future__ import annotations

import argparse
import html
import json
import os
import sys

# Inline node type -> (tag, class). ``cite`` and ``dfn`` carry real meaning
# here: a book name cited in a note, and a glossary term at its definition.
INLINE_TAGS = {
    "wj": ("span", "wj"),          # words of Jesus
    "keyword": ("dfn", "k"),       # glossary headword
    "bookref": ("cite", "bk"),     # book title cited in a note
    "fq": ("span", "fq"),          # the words a footnote is about
    "fqa": ("span", "fqa"),        # an alternative rendering
    "fl": ("span", "fl"),          # footnote label
    "fine": ("span", "fine"),
    "xt": ("span", "xt"),          # cross-reference target
}

# Block type -> tag. Headings sit at h3 so the outline never skips a level:
# h1 book, h2 chapter, h3 section.
BLOCK_TAGS = {
    "paragraph": "p",
    "line": "p",
    "heading": "h3",
    "title": "p",
    "speaker": "p",
    "item": "li",
}



def esc(text):
    return html.escape(text, quote=False)


def verse_id(chapter, label):
    """Page-unique verse anchor, e.g. v23_1 (or v11_15-16 for a range)."""
    return "v%d_%s" % (chapter, label)


def ref_href(node, book, chapter):
    """Link an intra-corpus reference; whole books are single pages."""
    target_book = node.get("book") or book
    target_ch = node.get("chapter", chapter)
    verse = node.get("verse")
    base = "" if target_book == book else target_book
    if verse:
        return "%s#%s" % (base, verse_id(target_ch, verse))
    return "%s#ch%d" % (base, target_ch)


def render_inline(nodes, book, chapter, out):
    for node in nodes:
        kind = node["t"]
        if kind == "text":
            out.append(esc(node["v"]))
        elif kind == "verse":
            # Trailing space keeps the number off the text before any CSS
            # lands; style .v with padding and it stays correct either way.
            out.append('<span class="v" id="%s">%s</span> ' % (
                verse_id(chapter, node["label"]), esc(node["label"])))
        elif kind == "noteref":
            n = node["id"].replace("FN", "")
            out.append('<a class="noteref" id="fnref%s_%s" href="#fn%s_%s">'
                       "<sup>%s</sup></a>" % (chapter, n, chapter, n,
                                              esc(node.get("marker") or "*")))
        elif kind == "br":
            out.append("<br>")
        elif kind == "ref":
            out.append('<a class="ref" href="%s">' % ref_href(node, book, chapter))
            render_inline(node.get("c", []), book, chapter, out)
            out.append("</a>")
        elif kind in INLINE_TAGS:
            tag, cls = INLINE_TAGS[kind]
            out.append('<%s class="%s">' % (tag, cls))
            render_inline(node.get("c", []), book, chapter, out)
            out.append("</%s>" % tag)
        else:  # unknown node type: keep the words, drop the wrapper
            render_inline(node.get("c", []), book, chapter, out)


def render_block(block, book, chapter, out):
    btype = block["type"]
    tag = BLOCK_TAGS.get(btype, "p")
    classes = [block["style"]]
    attrs = ""
    if "indent" in block:
        attrs += ' data-indent="%d"' % block["indent"]
    if btype == "line":
        classes.append("line")
    out.append("      <%s class=\"%s\"%s>" % (tag, " ".join(classes), attrs))
    render_inline(block.get("content", []), book, chapter, out)
    out.append("</%s>\n" % tag)


def render_notes(notes, chapter, book, out):
    if not notes:
        return
    out.append('      <section class="footnotes">\n')
    out.append('        <h4 class="footnotes-title">Notes</h4>\n')
    out.append("        <ol>\n")
    for note in notes:
        n = (note["id"] or "").replace("FN", "")
        out.append('          <li class="note" id="fn%s_%s" data-kind="%s">'
                   % (chapter, n, note["kind"]))
        out.append('<span class="marker">%s</span> ' % esc(note.get("marker") or "*"))
        if note.get("ref"):
            out.append('<a class="backref" href="#fnref%s_%s">%s</a> '
                       % (chapter, n, esc(note["ref"])))
        out.append('<span class="ft">')
        render_inline(note["content"], book, chapter, out)
        out.append("</span></li>\n")
    out.append("        </ol>\n      </section>\n")


def render_chapter(chapter, book, out):
    num = chapter["number"]
    out.append('    <section class="chapter" id="ch%d" data-chapter="%d">\n'
               % (num, num))
    out.append('      <h2 class="chapter-number">%d</h2>\n' % num)

    group = None  # "poetry" | "list" | None

    def close_group():
        nonlocal group
        if group == "poetry":
            out.append("      </div>\n")
        elif group == "list":
            out.append("      </ul>\n")
        group = None

    for block in chapter["blocks"]:
        btype = block["type"]
        if btype == "break":
            close_group()          # a blank line ends the stanza
            continue
        want = {"line": "poetry", "item": "list"}.get(btype)
        if want != group:
            close_group()
            if want == "poetry":
                out.append('      <div class="poetry">\n')
            elif want == "list":
                out.append('      <ul class="list">\n')
            group = want
        render_block(block, book, num, out)
    close_group()

    render_notes(chapter["notes"], num, book, out)
    out.append("    </section>\n")


def render_book(book, translation, out_dir):
    code, name = book["code"], book["name"]
    out = []
    title = "%s — %s" % (name, translation["name"])
    # A fragment: the title the shell will use, then one root element whose
    # data-template names the template that wraps it.
    out.append("<title>%s</title>\n" % esc(title))
    out.append('<article class="book" data-template="book" id="%s" data-book="%s" '
               'data-name="%s" data-section="%s">\n'
               % (code, code, esc(name), book["section"]))

    # Header: the full multi-line title if the source had one.
    out.append('  <header class="book-header">\n')
    out.append("    <h1>")
    if book["titles"]:
        # Separated by a space, not run together. The spans record what USFM
        # called them -- mt2 and mt3 were lines above and below the main title
        # -- but they are set as one line here, and without the space between
        # them Genesis reads "The First Book of Moses,Commonly CalledGenesis".
        # The markup still says what each part is, so stacking them again is a
        # stylesheet away.
        out.append(" ".join('<span class="%s">%s</span>'
                            % (part["style"], esc(part["text"]))
                            for part in book["titles"]))
    else:
        out.append(esc(name))
    out.append("</h1>\n")
    out.append('    <nav class="chapter-nav" aria-label="Chapters" '
               'hx-boost="false">\n      <ul>\n')
    for chapter in book["chapters"]:
        out.append('        <li><a href="#ch%d">%d</a></li>\n'
                   % (chapter["number"], chapter["number"]))
    out.append("      </ul>\n    </nav>\n")
    out.append('    <p class="home"><a href="./">All books</a></p>\n')
    out.append("  </header>\n")

    out.append('  <div class="chapters">\n')
    for chapter in book["chapters"]:
        render_chapter(chapter, code, out)
    out.append("  </div>\n")

    out.append('  <footer class="colophon"><p>%s. %s.</p></footer>\n'
               % (esc(translation["name"]), esc(translation["license"])))
    out.append("</article>\n")

    path = os.path.join(out_dir, "%s.html" % code)
    with open(path, "w", encoding="utf-8") as fh:
        fh.write("".join(out))
    return path


SECTION_LABELS = [
    ("ot", "Old Testament"),
    ("nt", "New Testament"),
    ("deuterocanon", "Deuterocanon"),
    ("other", "Other"),
]


def render_index(books, translation, out_dir):
    out = ["<title>%s</title>\n" % esc(translation["name"]),
           '<div class="index" data-template="index">\n']
    for key, label in SECTION_LABELS:
        group = [b for b in books if b["section"] == key]
        if not group:
            continue
        out.append('  <section class="book-group" data-section="%s">\n' % key)
        out.append("    <h2>%s</h2>\n    <ul>\n" % esc(label))
        for book in group:
            out.append('      <li><a href="%s">%s</a> '
                       '<span class="count">%d</span></li>\n'
                       % (book["code"], esc(book["name"]), len(book["chapters"])))
        out.append("    </ul>\n  </section>\n")
    out.append('  <footer class="colophon"><p>%s. %s.</p></footer>\n'
               % (esc(translation["name"]), esc(translation["license"])))
    out.append("</div>\n")
    path = os.path.join(out_dir, "index.html")
    with open(path, "w", encoding="utf-8") as fh:
        fh.write("".join(out))
    return path



def main(argv=None):
    ap = argparse.ArgumentParser(description=__doc__,
                                 formatter_class=argparse.RawDescriptionHelpFormatter)
    ap.add_argument("-i", "--input", default="bible.json",
                    help="JSON from extract_bible.py (default: bible.json)")
    ap.add_argument("-o", "--out", default="books",
                    help="output directory (default: books)")
    args = ap.parse_args(argv)

    with open(args.input, encoding="utf-8") as fh:
        data = json.load(fh)
    os.makedirs(args.out, exist_ok=True)

    total = 0
    for book in data["books"]:
        path = render_book(book, data["translation"], args.out)
        total += os.path.getsize(path)
    render_index(data["books"], data["translation"], args.out)

    print("books   %d" % len(data["books"]), file=sys.stderr)
    print("html    %.1f MB total, %.0f KB average"
          % (total / 1e6, total / len(data["books"]) / 1e3), file=sys.stderr)
    print("wrote   %s/" % args.out, file=sys.stderr)
    return 0


if __name__ == "__main__":
    sys.exit(main())