pptx_builder.py

import io
import os
import tempfile
import urllib.request
import urllib.parse
from pptx import Presentation
from pptx.util import Inches, Pt, Emu
from pptx.dml.color import RGBColor
from pptx.enum.text import PP_ALIGN
from pptx.oxml.ns import qn
from lxml import etree

SLIDE_W = Inches(13.33)
SLIDE_H = Inches(7.5)

THEMES = {
    "Professional": {
        "primary":    RGBColor(0x1B, 0x6C, 0xA8),
        "secondary":  RGBColor(0x19, 0xA8, 0x8A),
        "dark":       RGBColor(0x0D, 0x1B, 0x2A),
        "light":      RGBColor(0xF4, 0xF8, 0xFF),
        "white":      RGBColor(0xFF, 0xFF, 0xFF),
        "text_dark":  RGBColor(0x0D, 0x1B, 0x2A),
        "text_muted": RGBColor(0x5A, 0x7A, 0x9A),
    },
    "Creative": {
        "primary":    RGBColor(0x8B, 0x5C, 0xF6),
        "secondary":  RGBColor(0xF5, 0x9E, 0x0B),
        "dark":       RGBColor(0x1E, 0x1B, 0x4B),
        "light":      RGBColor(0xF9, 0xF7, 0xFF),
        "white":      RGBColor(0xFF, 0xFF, 0xFF),
        "text_dark":  RGBColor(0x1E, 0x1B, 0x4B),
        "text_muted": RGBColor(0x6D, 0x28, 0xD9),
    },
    "Academic": {
        "primary":    RGBColor(0x15, 0x56, 0x24),
        "secondary":  RGBColor(0xD9, 0x77, 0x06),
        "dark":       RGBColor(0x0F, 0x2D, 0x17),
        "light":      RGBColor(0xF2, 0xFB, 0xF3),
        "white":      RGBColor(0xFF, 0xFF, 0xFF),
        "text_dark":  RGBColor(0x0F, 0x2D, 0x17),
        "text_muted": RGBColor(0x3A, 0x6A, 0x4A),
    },
    "Startup": {
        "primary":    RGBColor(0xEF, 0x44, 0x44),
        "secondary":  RGBColor(0x06, 0xB6, 0xD4),
        "dark":       RGBColor(0x09, 0x09, 0x0B),
        "light":      RGBColor(0xFA, 0xFA, 0xFC),
        "white":      RGBColor(0xFF, 0xFF, 0xFF),
        "text_dark":  RGBColor(0x09, 0x09, 0x0B),
        "text_muted": RGBColor(0x55, 0x60, 0x70),
    },
}

# ── Image fetching ─────────────────────────────────────────────────────────

IMAGE_SOURCES = [
    # loremflickr — keyword-based, reliable, no API key
    lambda kw, w, h: f"https://loremflickr.com/{w}/{h}/{urllib.parse.quote(kw)}",
    # picsum — random beautiful photo (fallback)
    lambda kw, w, h: f"https://picsum.photos/seed/{urllib.parse.quote(kw)}/{w}/{h}",
]

def _fetch_image(keyword: str, width: int = 560, height: int = 420) -> str | None:
    if not keyword:
        return None
    for source_fn in IMAGE_SOURCES:
        try:
            url = source_fn(keyword.strip(), width, height)
            tmp = tempfile.NamedTemporaryFile(suffix=".jpg", delete=False)
            req = urllib.request.Request(
                url, headers={"User-Agent": "Mozilla/5.0 SlideAI/1.0"}
            )
            with urllib.request.urlopen(req, timeout=10) as resp:
                data = resp.read()
            if len(data) > 2000:          # real image, not an error page
                tmp.write(data)
                tmp.close()
                return tmp.name
            tmp.close()
        except Exception:
            continue
    return None

# ── Drawing helpers ────────────────────────────────────────────────────────

def _blank_slide(prs):
    return prs.slides.add_slide(prs.slide_layouts[6])

def _fill(shape, color):
    shape.fill.solid()
    shape.fill.fore_color.rgb = color
    shape.line.fill.background()

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

def _rect(slide, l, t, w, h, color):
    s = slide.shapes.add_shape(1, l, t, w, h)
    _fill(s, color)
    return s

def _oval(slide, l, t, w, h, color, alpha=0.15):
    s = slide.shapes.add_shape(9, l, t, w, h)
    _fill(s, color)
    try:
        sf = s.element.spPr.find(qn("a:solidFill"))
        if sf is not None:
            sc = sf.find(qn("a:srgbClr"))
            if sc is not None:
                ae = etree.SubElement(sc, qn("a:alpha"))
                ae.set("val", str(int(alpha * 100000)))
    except Exception:
        pass
    return s

def _txbox(slide, text, l, t, w, h, size, bold, color,
           align=PP_ALIGN.LEFT, italic=False):
    tb = slide.shapes.add_textbox(l, t, w, h)
    tf = tb.text_frame
    tf.word_wrap = True
    p = tf.paragraphs[0]
    p.alignment = align
    r = p.add_run()
    r.text = text
    r.font.name = "Calibri"
    r.font.size = Pt(size)
    r.font.bold = bold
    r.font.italic = italic
    r.font.color.rgb = color
    return tb

def _spc(para, before_pt=0, after_pt=0):
    pPr = para._p.get_or_add_pPr()
    if before_pt:
        sb = etree.SubElement(pPr, qn("a:spcBef"))
        etree.SubElement(sb, qn("a:spcPts")).set("val", str(before_pt * 100))
    if after_pt:
        sa = etree.SubElement(pPr, qn("a:spcAft"))
        etree.SubElement(sa, qn("a:spcPts")).set("val", str(after_pt * 100))

# ── Slide builders ─────────────────────────────────────────────────────────

def _build_title_slide(prs, data, t, total):
    slide = _blank_slide(prs)
    _set_bg(slide, t["dark"])

    # Background image with dark overlay
    img_path = _fetch_image(data.get("image_keyword", ""), 1200, 700)
    if img_path:
        try:
            pic = slide.shapes.add_picture(img_path, 0, 0, SLIDE_W, SLIDE_H)
            slide.shapes._spTree.remove(pic._element)
            slide.shapes._spTree.insert(2, pic._element)
            ov = _rect(slide, 0, 0, SLIDE_W, SLIDE_H, t["dark"])
            sf = ov.element.spPr.find(qn("a:solidFill"))
            if sf is not None:
                sc = sf.find(qn("a:srgbClr"))
                if sc is not None:
                    ae = etree.SubElement(sc, qn("a:alpha"))
                    ae.set("val", "78000")
        except Exception:
            pass

    _oval(slide, Inches(9.5), Inches(-1.5), Inches(6), Inches(6), t["primary"], 0.22)
    _oval(slide, Inches(-0.8), Inches(4.8), Inches(3.5), Inches(3.5), t["secondary"], 0.18)
    _rect(slide, 0, SLIDE_H - Inches(0.08), SLIDE_W, Inches(0.08), t["secondary"])
    _rect(slide, 0, Inches(1.5), Inches(0.06), Inches(4.5), t["primary"])

    tb = slide.shapes.add_textbox(Inches(0.5), Inches(1.8), Inches(12), Inches(2.5))
    tf = tb.text_frame; tf.word_wrap = True
    p = tf.paragraphs[0]; p.alignment = PP_ALIGN.LEFT
    r = p.add_run()
    r.text = data.get("title", "Presentation")
    r.font.name = "Calibri"; r.font.size = Pt(52)
    r.font.bold = True; r.font.color.rgb = t["white"]

    subtitle = data.get("subtitle", "")
    if subtitle:
        tb2 = slide.shapes.add_textbox(Inches(0.5), Inches(4.5), Inches(10), Inches(1))
        tf2 = tb2.text_frame; tf2.word_wrap = True
        p2 = tf2.paragraphs[0]; p2.alignment = PP_ALIGN.LEFT
        r2 = p2.add_run()
        r2.text = subtitle
        r2.font.name = "Calibri Light"; r2.font.size = Pt(24)
        r2.font.color.rgb = t["secondary"]

    _rect(slide, Inches(0.5), Inches(6.2), Inches(2.4), Inches(0.5), t["primary"])
    _txbox(slide, f"{total} slides", Inches(0.5), Inches(6.2),
           Inches(2.4), Inches(0.5), 11, False, t["white"], PP_ALIGN.CENTER)

    slide.notes_slide.notes_text_frame.text = data.get("speaker_notes", "")


def _build_content_slide(prs, data, slide_num, total, t):
    slide = _blank_slide(prs)
    _set_bg(slide, t["light"])

    img_path = _fetch_image(data.get("image_keyword", ""), 560, 430)
    has_image = img_path is not None

    # ── Header band ──────────────────────────────────────────────────────
    _rect(slide, 0, 0, SLIDE_W, Inches(1.4), t["primary"])
    _rect(slide, SLIDE_W - Inches(1.4), 0, Inches(1.4), Inches(1.4), t["secondary"])
    _txbox(slide, f"{slide_num:02d}",
           SLIDE_W - Inches(1.4), Inches(0.05), Inches(1.4), Inches(1.3),
           36, True, t["white"], PP_ALIGN.CENTER)
    _txbox(slide, data.get("title", ""),
           Inches(0.5), Inches(0.12), SLIDE_W - Inches(2.2), Inches(1.15),
           26, True, t["white"])

    # ── Left accent ───────────────────────────────────────────────────────
    _rect(slide, 0, Inches(1.4), Inches(0.06), SLIDE_H - Inches(1.75), t["secondary"])

    # ── Bullets ───────────────────────────────────────────────────────────
    bullets = data.get("bullets", [])
    text_w = Inches(7.6) if has_image else Inches(12.8)

    cb = slide.shapes.add_textbox(Inches(0.3), Inches(1.6), text_w, Inches(5.55))
    tf = cb.text_frame
    tf.word_wrap = True

    ICONS = ["①", "②", "③", "④", "⑤", "⑥", "⑦"]
    for idx, bullet in enumerate(bullets[:7]):
        p = tf.paragraphs[0] if idx == 0 else tf.add_paragraph()
        p.alignment = PP_ALIGN.LEFT
        if idx > 0:
            _spc(p, before_pt=5)

        rn = p.add_run()
        rn.text = f"{ICONS[idx]}  "
        rn.font.name = "Segoe UI"
        rn.font.size = Pt(17)
        rn.font.bold = True
        rn.font.color.rgb = t["primary"]

        rt = p.add_run()
        rt.text = bullet
        rt.font.name = "Calibri"
        rt.font.size = Pt(17)
        rt.font.bold = False
        rt.font.color.rgb = t["text_dark"]

    # ── Image panel ───────────────────────────────────────────────────────
    if has_image:
        il = Inches(8.2); it = Inches(1.55)
        iw = Inches(4.85); ih = Inches(5.55)

        # Border frame
        _rect(slide, il - Inches(0.07), it - Inches(0.07),
              iw + Inches(0.14), ih + Inches(0.14), t["secondary"])

        try:
            slide.shapes.add_picture(img_path, il, it, iw, ih)
        except Exception:
            _rect(slide, il, it, iw, ih, t["primary"])
            _txbox(slide, data.get("image_keyword", "").title(),
                   il + Inches(0.3), it + Inches(2.2), iw - Inches(0.6), Inches(1),
                   14, False, t["white"], PP_ALIGN.CENTER)

    # ── Footer ────────────────────────────────────────────────────────────
    _rect(slide, 0, SLIDE_H - Inches(0.32), SLIDE_W, Inches(0.32), t["primary"])
    _txbox(slide, f"Slide {slide_num} of {total}",
           SLIDE_W - Inches(2.5), SLIDE_H - Inches(0.32),
           Inches(2.4), Inches(0.32), 9, False, t["white"], PP_ALIGN.RIGHT)

    slide.notes_slide.notes_text_frame.text = data.get("speaker_notes", "")


def _build_closing_slide(prs, title, t):
    slide = _blank_slide(prs)
    _set_bg(slide, t["dark"])
    _oval(slide, Inches(-1), Inches(-1), Inches(5), Inches(5), t["secondary"], 0.15)
    _oval(slide, Inches(10), Inches(3.5), Inches(5), Inches(5), t["primary"], 0.18)
    _rect(slide, 0, SLIDE_H - Inches(0.08), SLIDE_W, Inches(0.08), t["secondary"])
    _rect(slide, 0, Inches(1.5), Inches(0.06), Inches(4.5), t["secondary"])
    _txbox(slide, "Thank You", Inches(0.5), Inches(1.8), Inches(12), Inches(2),
           60, True, t["white"])
    _txbox(slide, title, Inches(0.5), Inches(4.1), Inches(10), Inches(0.8),
           22, False, t["secondary"])
    _rect(slide, Inches(0.5), Inches(5.1), Inches(3), Inches(0.05), t["primary"])
    _txbox(slide, "Questions & Discussion",
           Inches(0.5), Inches(5.3), Inches(8), Inches(0.6),
           16, False, t["white"])


# ── Entry point ────────────────────────────────────────────────────────────

def build_pptx(presentation_data: dict, style: str) -> bytes:
    t = THEMES.get(style, THEMES["Professional"])
    prs = Presentation()
    prs.slide_width = SLIDE_W
    prs.slide_height = SLIDE_H

    slides = presentation_data.get("slides", [])
    pres_title = presentation_data.get("title", "Presentation")
    total = len(slides) + 1  # +1 for closing slide

    title_slides  = [s for s in slides if s.get("type") == "title"]
    content_slides = [s for s in slides if s.get("type") != "title"]

    for s in title_slides:
        _build_title_slide(prs, s, t, total)

    for i, s in enumerate(content_slides):
        _build_content_slide(prs, s, i + 2, total, t)

    _build_closing_slide(prs, pres_title, t)

    buf = io.BytesIO()
    prs.save(buf)
    buf.seek(0)
    return buf.getvalue()