#!/usr/bin/env python3
"""
Convert session markdown slides to styled PowerPoint presentations.

Run from the infy/ directory:
    python3 scripts/convert_slides_to_pptx.py

Requires: pip install python-pptx
"""

import re
from pptx import Presentation
from pptx.util import Inches, Pt
from pptx.dml.color import RGBColor
from pptx.enum.text import PP_ALIGN

# ── Brand colours ───────────────────────────────────────────────────────────
HF_ORANGE   = RGBColor(0xFF, 0x6B, 0x35)   # Hugging Face orange
HF_DARK     = RGBColor(0x1C, 0x1C, 0x1C)   # Near-black
HF_BLUE     = RGBColor(0x00, 0x62, 0xCC)   # Accent blue
CODE_BG     = RGBColor(0xF0, 0xF0, 0xF0)   # Light grey (code bg)
CODE_FG     = RGBColor(0x2D, 0x2D, 0x2D)   # Dark (code text)
SUBHEAD_CLR = RGBColor(0x00, 0x62, 0xCC)   # Blue subheadings
TEXT_CLR    = RGBColor(0x33, 0x33, 0x33)   # Body text
WHITE       = RGBColor(0xFF, 0xFF, 0xFF)
INLINE_CODE = RGBColor(0xC7, 0x26, 0x3B)   # Red-ish for inline code
QUOTE_BG    = RGBColor(0xFF, 0xF3, 0xED)   # Light orange (blockquote bg)
TABLE_HDR   = RGBColor(0xFF, 0x6B, 0x35)   # Header row colour
BORDER_CLR  = RGBColor(0xCC, 0xCC, 0xCC)   # Light grey border

# ── Slide dimensions (widescreen 16:9) ──────────────────────────────────────
SW          = Inches(13.33)
SH          = Inches(7.5)
MARGIN      = Inches(0.5)
TITLE_H     = Inches(1.2)
BODY_TOP    = Inches(1.45)
BODY_BOTTOM = Inches(7.2)
BODY_W      = SW - 2 * MARGIN

# ── Low-level helpers ────────────────────────────────────────────────────────

def _set_bg(slide, rgb: RGBColor):
    f = slide.background.fill
    f.solid()
    f.fore_color.rgb = rgb


def _add_rect(slide, x, y, w, h, rgb: RGBColor, border_rgb=None):
    shape = slide.shapes.add_shape(1, x, y, w, h)   # 1 = rectangle
    shape.fill.solid()
    shape.fill.fore_color.rgb = rgb
    if border_rgb:
        shape.line.color.rgb = border_rgb
        shape.line.width = Pt(0.5)
    else:
        shape.line.color.rgb = rgb   # same colour as fill → invisible border
    return shape


def _add_runs(para, text: str, base_size, base_color: RGBColor, base_bold=False):
    """Append inline-formatted runs (**bold** and `code`) to an existing paragraph."""
    parts = re.split(r'(\*\*[^*]+?\*\*|`[^`]+?`|\*[^*]+?\*)', text)
    for part in parts:
        if not part:
            continue
        run = para.add_run()
        if part.startswith('**') and part.endswith('**'):
            run.text = part[2:-2]
            run.font.bold = True
            run.font.size = base_size
            run.font.color.rgb = base_color
        elif part.startswith('`') and part.endswith('`'):
            run.text = part[1:-1]
            run.font.name = 'Courier New'
            run.font.size = Pt(max(base_size.pt - 2, 10))
            run.font.color.rgb = INLINE_CODE
        elif part.startswith('*') and part.endswith('*'):
            run.text = part[1:-1]
            run.font.italic = True
            run.font.size = base_size
            run.font.color.rgb = base_color
        else:
            run.text = part
            run.font.bold = base_bold
            run.font.size = base_size
            run.font.color.rgb = base_color


# ── Markdown parser ──────────────────────────────────────────────────────────

def parse_slides(content: str):
    """
    Split content into a list of (title, items[]) tuples, one per slide.

    A new slide begins whenever a `---`-separated block starts with a #/##
    heading.  Continuation blocks (no heading) are merged into the previous
    slide so that e.g. presenter details on a title slide don't become a
    separate slide.
    """
    raw_blocks = re.split(r'\n---\n', content)
    merged = []
    current = None
    for block in raw_blocks:
        block = block.strip()
        if not block:
            continue
        if re.match(r'^#{1,2} ', block):
            if current is not None:
                merged.append(current)
            current = block
        else:
            if current is not None:
                current += '\n' + block
            else:
                current = block
    if current:
        merged.append(current)

    return [_parse_one_slide(s) for s in merged]


def _parse_one_slide(raw: str):
    """
    Parse one slide's text into (title, items[]).

    Item shapes:
      {'type': 'subheading', 'text': str}
      {'type': 'bullet',     'text': str, 'level': int}
      {'type': 'code',       'lines': list[str]}
      {'type': 'quote',      'text': str}
      {'type': 'table_row',  'cells': list[str], 'header': bool}
      {'type': 'text',       'text': str}
      {'type': 'separator'}
    """
    lines = raw.strip().split('\n')
    title = ''
    items = []
    title_found = False
    in_code = False
    code_buf = []
    table_next_header = True

    for line in lines:
        # ── Code fence ──
        if line.strip().startswith('```'):
            if in_code:
                items.append({'type': 'code', 'lines': list(code_buf)})
                code_buf.clear()
                in_code = False
            else:
                in_code = True
            continue
        if in_code:
            code_buf.append(line)
            continue

        # ── Slide title (first # or ## heading) ──
        if not title_found:
            if line.startswith('## ') or line.startswith('# '):
                raw_title = re.sub(r'^#{1,2} ', '', line).strip()
                title = re.sub(r'^Slide \d+[\.:]\s*', '', raw_title)
                title_found = True
                continue

        # ── Decorative separator inside a slide ──
        if line.strip() in ('---', '***'):
            items.append({'type': 'separator'})
            continue

        # ── ### subheading ──
        if line.startswith('### '):
            items.append({'type': 'subheading', 'text': line[4:].strip()})
            table_next_header = True
            continue

        # ── Blockquote ──
        if line.startswith('> '):
            items.append({'type': 'quote', 'text': line[2:].strip()})
            continue

        # ── Table row ──
        if line.strip().startswith('|'):
            if re.match(r'^\|[\-\s\|:]+\|$', line.strip()):
                table_next_header = False
                continue   # separator row
            cells = [c.strip() for c in line.strip().strip('|').split('|')]
            items.append({'type': 'table_row', 'cells': cells,
                          'header': table_next_header})
            table_next_header = False
            continue

        # ── Bullet / numbered list ──
        m = re.match(r'^(\s*)([-*•]|\d+\.)\s+(.+)$', line)
        if m:
            level = len(m.group(1)) // 2
            items.append({'type': 'bullet', 'text': m.group(3), 'level': level})
            table_next_header = True
            continue

        # ── Empty line ──
        if not line.strip():
            continue

        # ── Plain / bold text ──
        items.append({'type': 'text', 'text': line.strip()})
        table_next_header = True

    return title, items


# ── Slide renderer ───────────────────────────────────────────────────────────

def _get_blank_layout(prs):
    for layout in prs.slide_layouts:
        if 'blank' in layout.name.lower():
            return layout
    return prs.slide_layouts[6]


def render_slide(prs: Presentation, title: str, items: list):
    """Add one fully-styled slide to the presentation."""
    slide = prs.slides.add_slide(_get_blank_layout(prs))
    _set_bg(slide, WHITE)

    # ─ Orange title bar ─
    _add_rect(slide, 0, 0, SW, TITLE_H, HF_ORANGE)
    _add_rect(slide, 0, TITLE_H, SW, Inches(0.045), HF_DARK)

    # ─ Title text ─
    tb = slide.shapes.add_textbox(MARGIN, Inches(0.22), BODY_W, Inches(0.92))
    tf = tb.text_frame
    tf.word_wrap = True
    p = tf.paragraphs[0]
    run = p.add_run()
    run.text = title or 'Slide'
    run.font.size = Pt(30)
    run.font.bold = True
    run.font.color.rgb = WHITE

    # ─ Body ─
    y = BODY_TOP
    table_rows = []

    def flush_table():
        nonlocal y
        if not table_rows:
            return
        row_h = Inches(0.32)
        h = row_h * len(table_rows) + Inches(0.15)
        if y + h > BODY_BOTTOM:
            table_rows.clear()
            return
        _add_rect(slide, MARGIN, y, BODY_W, h,
                  RGBColor(0xF8, 0xF8, 0xF8), border_rgb=BORDER_CLR)
        ttb = slide.shapes.add_textbox(
            MARGIN + Inches(0.12), y + Inches(0.06),
            BODY_W - Inches(0.24), h - Inches(0.1))
        ttf = ttb.text_frame
        ttf.word_wrap = True
        for i, row_item in enumerate(table_rows):
            tp = ttf.paragraphs[0] if i == 0 else ttf.add_paragraph()
            is_hdr = row_item.get('header', False)
            run = tp.add_run()
            run.text = '  │  '.join(row_item['cells'])
            run.font.size = Pt(12)
            run.font.name = 'Courier New'
            run.font.bold = is_hdr
            run.font.color.rgb = TABLE_HDR if is_hdr else HF_DARK
        y += h + Inches(0.1)
        table_rows.clear()

    for item in items:
        # flush pending table if moving to a non-table item
        if item['type'] != 'table_row' and table_rows:
            flush_table()

        itype = item['type']

        # ── Code block ──────────────────────────────────────────────────────
        if itype == 'code':
            code_lines = item['lines']
            n = len(code_lines)
            if n == 0:
                continue
            h = Inches(0.26) * n + Inches(0.22)
            h = min(h, BODY_BOTTOM - y)
            if y + Inches(0.4) > BODY_BOTTOM:
                continue
            _add_rect(slide, MARGIN, y, BODY_W, h, CODE_BG, border_rgb=BORDER_CLR)
            ctb = slide.shapes.add_textbox(
                MARGIN + Inches(0.15), y + Inches(0.1),
                BODY_W - Inches(0.3), h - Inches(0.15))
            ctf = ctb.text_frame
            ctf.word_wrap = False
            visible = max(1, int((h - Inches(0.15)) / Inches(0.26)))
            for i, cl in enumerate(code_lines[:visible]):
                cp = ctf.paragraphs[0] if i == 0 else ctf.add_paragraph()
                run = cp.add_run()
                run.text = cl
                run.font.name = 'Courier New'
                run.font.size = Pt(11)
                run.font.color.rgb = CODE_FG
            y += h + Inches(0.12)

        # ── Table row ───────────────────────────────────────────────────────
        elif itype == 'table_row':
            table_rows.append(item)

        # ── ### Subheading ──────────────────────────────────────────────────
        elif itype == 'subheading':
            h = Inches(0.44)
            if y + h > BODY_BOTTOM:
                continue
            stb = slide.shapes.add_textbox(MARGIN, y, BODY_W, h)
            stf = stb.text_frame
            stf.word_wrap = True
            p = stf.paragraphs[0]
            _add_runs(p, item['text'], Pt(19), SUBHEAD_CLR, base_bold=True)
            y += h

        # ── Blockquote ──────────────────────────────────────────────────────
        elif itype == 'quote':
            h = Inches(0.5)
            if y + h > BODY_BOTTOM:
                continue
            _add_rect(slide, MARGIN, y, Inches(0.08), h, HF_ORANGE)
            _add_rect(slide, MARGIN + Inches(0.08), y,
                      BODY_W - Inches(0.08), h, QUOTE_BG)
            qtb = slide.shapes.add_textbox(
                MARGIN + Inches(0.22), y + Inches(0.07),
                BODY_W - Inches(0.3), h - Inches(0.1))
            qtf = qtb.text_frame
            qtf.word_wrap = True
            qp = qtf.paragraphs[0]
            _add_runs(qp, item['text'], Pt(17), HF_DARK, base_bold=True)
            y += h + Inches(0.06)

        # ── Bullet ──────────────────────────────────────────────────────────
        elif itype == 'bullet':
            level = item.get('level', 0)
            indent = Inches(0.36 * (level + 1))
            h = Inches(0.34)
            if y + h > BODY_BOTTOM:
                continue
            dot = '▸ ' if level == 0 else '◦ '
            btb = slide.shapes.add_textbox(
                MARGIN + indent, y, BODY_W - indent, h)
            btf = btb.text_frame
            btf.word_wrap = True
            bp = btf.paragraphs[0]
            mr = bp.add_run()
            mr.text = dot
            mr.font.size = Pt(15)
            mr.font.color.rgb = HF_ORANGE
            mr.font.bold = True
            _add_runs(bp, item['text'], Pt(15), TEXT_CLR)
            y += h

        # ── Separator ───────────────────────────────────────────────────────
        elif itype == 'separator':
            if y + Inches(0.15) <= BODY_BOTTOM:
                _add_rect(slide, MARGIN, y + Inches(0.06),
                          BODY_W, Inches(0.02), BORDER_CLR)
                y += Inches(0.2)

        # ── Plain / bold text ───────────────────────────────────────────────
        elif itype == 'text':
            text = item['text']
            h = Inches(0.36)
            if y + h > BODY_BOTTOM:
                continue
            txtb = slide.shapes.add_textbox(MARGIN, y, BODY_W, h)
            txtf = txtb.text_frame
            txtf.word_wrap = True
            p = txtf.paragraphs[0]
            _add_runs(p, text, Pt(15), TEXT_CLR)
            y += h

    # flush any remaining table
    if table_rows:
        flush_table()


# ── Main ─────────────────────────────────────────────────────────────────────

def markdown_to_pptx(md_file: str, pptx_file: str):
    with open(md_file, 'r', encoding='utf-8') as f:
        content = f.read()

    parsed = parse_slides(content)
    prs = Presentation()
    prs.slide_width = SW
    prs.slide_height = SH

    for title, items in parsed:
        render_slide(prs, title, items)

    prs.save(pptx_file)
    print(f'✅  {md_file}  →  {pptx_file}  ({len(parsed)} slides)')


if __name__ == '__main__':
    print('=' * 60)
    print('📊  Converting Markdown Slides → PowerPoint')
    print('=' * 60 + '\n')

    try:
        markdown_to_pptx('slides/SESSION1_SLIDES.md', 'slides/SESSION1_SLIDES.pptx')
        markdown_to_pptx('slides/SESSION2_SLIDES.md', 'slides/SESSION2_SLIDES.pptx')
        print('\n✅  All done!')
        print('   slides/SESSION1_SLIDES.pptx')
        print('   slides/SESSION2_SLIDES.pptx')
    except ImportError as e:
        print(f'❌  Missing dependency: {e}')
        print('\n   Install with:  pip3 install python-pptx')
    except Exception as e:
        import traceback
        traceback.print_exc()
        print(f'\n❌  Error: {e}')