from pptx import Presentation
from pptx.util import Inches, Pt, Emu
from pptx.dml.color import RGBColor
from pptx.enum.text import PP_ALIGN, MSO_ANCHOR
from pptx.oxml.ns import qn
from pptx.oxml import parse_xml
from lxml import etree
from io import BytesIO

# Color palette - medical/professional
BG_DARK   = RGBColor(0x0D, 0x2B, 0x45)   # deep navy
BG_MID    = RGBColor(0x10, 0x4E, 0x8B)   # rich blue
ACCENT    = RGBColor(0x00, 0xB4, 0xD8)   # cyan accent
ACCENT2   = RGBColor(0x90, 0xE0, 0xEF)   # light cyan
WHITE     = RGBColor(0xFF, 0xFF, 0xFF)
LIGHT_BG  = RGBColor(0xE8, 0xF4, 0xFD)   # very light blue
DARK_TEXT = RGBColor(0x0D, 0x2B, 0x45)
GOLD      = RGBColor(0xFF, 0xC3, 0x00)   # gold accent

prs = Presentation()
prs.slide_width  = Inches(13.333)
prs.slide_height = Inches(7.5)
blank = prs.slide_layouts[6]  # fully blank

def hex_to_rgb(hex_str):
    h = hex_str.lstrip('#')
    return tuple(int(h[i:i+2], 16) for i in (0, 2, 4))

def add_rect(slide, x, y, w, h, fill_color, alpha=None):
    shape = slide.shapes.add_shape(1, Inches(x), Inches(y), Inches(w), Inches(h))
    shape.line.fill.background()
    fill = shape.fill
    fill.solid()
    fill.fore_color.rgb = fill_color
    return shape

def add_textbox(slide, text, x, y, w, h, font_size=18, bold=False, color=WHITE,
                align=PP_ALIGN.LEFT, italic=False, wrap=True):
    tb = slide.shapes.add_textbox(Inches(x), Inches(y), Inches(w), Inches(h))
    tf = tb.text_frame
    tf.word_wrap = wrap
    tf.auto_size = None
    tf.margin_left  = Pt(4)
    tf.margin_right = Pt(4)
    tf.margin_top   = Pt(2)
    tf.margin_bottom= Pt(2)
    p = tf.paragraphs[0]
    p.alignment = align
    run = p.add_run()
    run.text = text
    run.font.size  = Pt(font_size)
    run.font.bold  = bold
    run.font.italic = italic
    run.font.color.rgb = color
    run.font.name  = "Calibri"
    return tb

def add_bullet_slide(slide, title, bullets, subtitle=None):
    # Full background
    add_rect(slide, 0, 0, 13.333, 7.5, BG_DARK)
    # Left accent bar
    add_rect(slide, 0, 0, 0.12, 7.5, ACCENT)
    # Title bar
    add_rect(slide, 0.12, 0, 13.22, 1.3, BG_MID)
    # Title text
    add_textbox(slide, title, 0.35, 0.1, 12.6, 1.1,
                font_size=28, bold=True, color=WHITE, align=PP_ALIGN.LEFT)
    if subtitle:
        add_textbox(slide, subtitle, 0.35, 1.3, 12.6, 0.45,
                    font_size=14, bold=False, color=ACCENT2, italic=True)
    # Content area
    y_start = 1.55 if not subtitle else 1.85
    content_h = 7.5 - y_start - 0.2
    tb = slide.shapes.add_textbox(
        Inches(0.5), Inches(y_start), Inches(12.5), Inches(content_h))
    tf = tb.text_frame
    tf.word_wrap = True
    tf.auto_size = None
    tf.margin_left  = Pt(4)
    tf.margin_right = Pt(4)
    tf.margin_top   = Pt(4)
    tf.margin_bottom= Pt(4)

    for i, bullet in enumerate(bullets):
        if i == 0:
            p = tf.paragraphs[0]
        else:
            p = tf.add_paragraph()
        p.space_before = Pt(6)
        p.space_after  = Pt(4)
        # bullet marker
        run0 = p.add_run()
        run0.text = "▶  "
        run0.font.size  = Pt(15)
        run0.font.color.rgb = ACCENT
        run0.font.name  = "Calibri"
        run0.font.bold  = True
        # bullet text
        run1 = p.add_run()
        run1.text = bullet
        run1.font.size  = Pt(18)
        run1.font.color.rgb = WHITE
        run1.font.name  = "Calibri"

def add_two_column_slide(slide, title, left_title, left_bullets, right_title, right_bullets):
    add_rect(slide, 0, 0, 13.333, 7.5, BG_DARK)
    add_rect(slide, 0, 0, 0.12, 7.5, ACCENT)
    add_rect(slide, 0.12, 0, 13.22, 1.25, BG_MID)
    add_textbox(slide, title, 0.35, 0.1, 12.6, 1.05,
                font_size=28, bold=True, color=WHITE)
    # Left column header
    add_rect(slide, 0.4, 1.4, 5.9, 0.55, ACCENT)
    add_textbox(slide, left_title, 0.45, 1.42, 5.8, 0.5,
                font_size=18, bold=True, color=BG_DARK, align=PP_ALIGN.CENTER)
    # Right column header
    add_rect(slide, 6.9, 1.4, 5.9, 0.55, GOLD)
    add_textbox(slide, right_title, 6.95, 1.42, 5.8, 0.5,
                font_size=18, bold=True, color=BG_DARK, align=PP_ALIGN.CENTER)

    def fill_col(x, bullets):
        tb = slide.shapes.add_textbox(
            Inches(x), Inches(2.05), Inches(5.8), Inches(5.1))
        tf = tb.text_frame
        tf.word_wrap = True
        tf.auto_size = None
        tf.margin_left = Pt(4)
        tf.margin_right = Pt(4)
        for i, b in enumerate(bullets):
            p = tf.paragraphs[0] if i == 0 else tf.add_paragraph()
            p.space_before = Pt(6)
            p.space_after  = Pt(4)
            r0 = p.add_run()
            r0.text = "•  "
            r0.font.size  = Pt(15)
            r0.font.color.rgb = ACCENT
            r0.font.name  = "Calibri"
            r0.font.bold  = True
            r1 = p.add_run()
            r1.text = b
            r1.font.size  = Pt(16)
            r1.font.color.rgb = WHITE
            r1.font.name  = "Calibri"

    fill_col(0.45, left_bullets)
    fill_col(6.95, right_bullets)

# ───────────────────────────────────────────────────────────
# SLIDE 1 – TITLE SLIDE
# ───────────────────────────────────────────────────────────
slide = prs.slides.add_slide(blank)
add_rect(slide, 0, 0, 13.333, 7.5, BG_DARK)
add_rect(slide, 0, 0, 13.333, 0.12, ACCENT)   # top bar
add_rect(slide, 0, 7.38, 13.333, 0.12, ACCENT) # bottom bar
add_rect(slide, 0, 2.0, 13.333, 3.5, BG_MID)
# Main title
add_textbox(slide,
    "Ultrasound-Guided Regional Blocks",
    0.5, 2.2, 12.333, 1.6,
    font_size=42, bold=True, color=WHITE, align=PP_ALIGN.CENTER)
# Subtitle
add_textbox(slide,
    "Introduction, Principles, Advantages & Disadvantages",
    0.5, 3.75, 12.333, 0.7,
    font_size=22, bold=False, color=ACCENT2, align=PP_ALIGN.CENTER, italic=True)
add_textbox(slide,
    "Department of Anaesthesiology",
    0.5, 4.6, 12.333, 0.5,
    font_size=18, bold=False, color=GOLD, align=PP_ALIGN.CENTER)
add_textbox(slide,
    "Source: Miller's Anesthesia, 10th Edition",
    0.5, 6.9, 12.333, 0.4,
    font_size=12, bold=False, color=ACCENT2, align=PP_ALIGN.CENTER, italic=True)

# ───────────────────────────────────────────────────────────
# SLIDE 2 – OVERVIEW / AGENDA
# ───────────────────────────────────────────────────────────
slide = prs.slides.add_slide(blank)
add_bullet_slide(slide,
    "Overview",
    [
        "History and evolution of regional anesthesia techniques",
        "What is ultrasound guidance and how does it work?",
        "Physics of ultrasound relevant to nerve imaging",
        "Key techniques: in-plane vs. out-of-plane approaches",
        "Advantages, disadvantages, and training considerations",
    ])

# ───────────────────────────────────────────────────────────
# SLIDE 3 – HISTORICAL EVOLUTION
# ───────────────────────────────────────────────────────────
slide = prs.slides.add_slide(blank)
add_bullet_slide(slide,
    "Historical Evolution of Regional Anesthesia",
    [
        "Regional anesthesia traditionally relied on anatomical landmarks and paraesthesia elicitation.",
        "Peripheral nerve stimulators (PNS) improved localization by triggering motor responses without paresthesia.",
        "Early ultrasound use in regional anesthesia was described in the 1990s for brachial plexus blocks.",
        "Widespread adoption of portable, high-resolution ultrasound began in the 2000s.",
        "Today, ultrasound guidance is considered the gold standard for most peripheral nerve blocks.",
    ],
    subtitle="From Landmark Techniques to Real-Time Imaging")

# ───────────────────────────────────────────────────────────
# SLIDE 4 – WHAT IS USG GUIDANCE?
# ───────────────────────────────────────────────────────────
slide = prs.slides.add_slide(blank)
add_bullet_slide(slide,
    "What is Ultrasound-Guided Regional Anesthesia?",
    [
        "USG regional anesthesia uses real-time sonographic imaging to guide needle placement near target nerves.",
        "It allows direct visualization of the peripheral nerve, surrounding structures, needle tip, and spread of local anesthetic.",
        "High-frequency transducers (>10 MHz) provide the resolution needed for peripheral nerve imaging.",
        "Sound waves reflected at tissue interfaces with different acoustic impedances generate the echoes seen on screen.",
        "This modality is also used to guide fascial plane blocks with relatively deep targets.",
    ],
    subtitle="Real-Time Visualization of Nerves and Needle")

# ───────────────────────────────────────────────────────────
# SLIDE 5 – PHYSICS OF ULTRASOUND
# ───────────────────────────────────────────────────────────
slide = prs.slides.add_slide(blank)
add_bullet_slide(slide,
    "Physics of Ultrasound Relevant to Nerve Blocks",
    [
        "Ultrasound is sound above 20,000 Hz; clinical imaging uses frequencies of 2–15+ MHz.",
        "Higher frequency (>10 MHz) gives better resolution but less tissue penetration — used for superficial nerves.",
        "Lower frequency (2–5 MHz) penetrates deeper tissues but at reduced resolution — used for deep blocks.",
        "Speed of sound in soft tissue is assumed to be 1540 m/s, enabling accurate depth measurement.",
        "Common artifacts include anisotropy, acoustic shadowing, bayonet artifact, and reverberation.",
    ],
    subtitle="Key Principles for Nerve Imaging")

# ───────────────────────────────────────────────────────────
# SLIDE 6 – NERVE APPEARANCE ON USG
# ───────────────────────────────────────────────────────────
slide = prs.slides.add_slide(blank)
add_bullet_slide(slide,
    "Sonographic Appearance of Peripheral Nerves",
    [
        "Peripheral nerves appear as hyperechoic (bright) fascicular structures on ultrasound — the 'honeycomb' appearance.",
        "High-frequency insonation (≥10 MHz) can distinguish nerves from tendons based on echotexture alone.",
        "Nerves are not easily compressible and show characteristic motion with extremity movement.",
        "The point of optimal visibility (POV) balances depth with branching pattern for best imaging.",
        "Nerve pathology — enlargement, fascicular crowding, or loss of fascicular pattern — can be detected sonographically.",
    ],
    subtitle="Identifying the Target: The Honeycomb Sign")

# ───────────────────────────────────────────────────────────
# SLIDE 7 – APPROACHES TO USG BLOCK
# ───────────────────────────────────────────────────────────
slide = prs.slides.add_slide(blank)
add_bullet_slide(slide,
    "Approaches to Regional Block with Ultrasound",
    [
        "Peripheral nerves are usually imaged in short axis (cross-section) rather than long axis.",
        "In-plane technique: needle approaches within the imaging plane — entire needle shaft and tip are visible.",
        "Out-of-plane technique: needle crosses the imaging plane and appears as an echogenic dot on screen.",
        "Offline marking uses skin markings before needle insertion; online imaging means real-time needle guidance.",
        "Adequate visualization of nerve, needle tip, and local anesthetic spread is more important than the approach used.",
    ],
    subtitle="In-Plane vs. Out-of-Plane Needling")

# ───────────────────────────────────────────────────────────
# SLIDE 8 – LOCAL ANESTHETIC SPREAD
# ───────────────────────────────────────────────────────────
slide = prs.slides.add_slide(blank)
add_bullet_slide(slide,
    "Confirming Successful Injection",
    [
        "Successful injection distributes local anesthetic around the nerve, clarifying the nerve border.",
        "The injectate should travel along the nerve path and separate the nerve from adjacent anatomic structures.",
        "Small-volume test injections (≤1 mL) of saline can confirm needle or catheter tip position.",
        "Gently wiggling the needle improves tip conspicuity on ultrasound when visibility is poor.",
        "Echogenic needle designs with textured surfaces improve needle tip detection regardless of insonation angle.",
    ],
    subtitle="Visualizing Local Anesthetic Spread")

# ───────────────────────────────────────────────────────────
# SLIDE 9 – ADVANTAGES (dedicated slide)
# ───────────────────────────────────────────────────────────
slide = prs.slides.add_slide(blank)
add_bullet_slide(slide,
    "Advantages of USG-Guided Regional Blocks",
    [
        "Real-time visualization of the nerve, needle tip, and local anesthetic spread enhances precision.",
        "Higher block success rates, faster onset times, and reduced number of needle passes compared to nerve stimulation.",
        "Potential to prevent intravascular and intraneural injection of local anesthetic, improving patient safety.",
        "Allows reduction in local anesthetic volume (volume-sparing effect), decreasing systemic toxicity risk.",
        "Enables fascial plane blocks and guides catheter placement for continuous peripheral nerve block techniques.",
    ],
    subtitle="Why Ultrasound Has Become the Gold Standard")

# ───────────────────────────────────────────────────────────
# SLIDE 10 – MORE ADVANTAGES (clinical)
# ───────────────────────────────────────────────────────────
slide = prs.slides.add_slide(blank)
add_bullet_slide(slide,
    "Clinical & Patient-Centred Advantages",
    [
        "Avoids need to elicit paresthesias — blocks can be performed in more sedated or uncooperative patients.",
        "Identifies anatomical variants and pathological nerve changes (e.g., diabetic neuropathy, Charcot–Marie–Tooth disease).",
        "Doppler imaging detects adjacent vasculature, reducing accidental vascular puncture and hematoma formation.",
        "Provides shorter block performance time and improved patient comfort during the procedure.",
        "Large systematic reviews confirm USG guidance improves both block safety and overall success rates.",
    ],
    subtitle="Beyond Technique — Impact on Patient Outcomes")

# ───────────────────────────────────────────────────────────
# SLIDE 11 – DISADVANTAGES
# ───────────────────────────────────────────────────────────
slide = prs.slides.add_slide(blank)
add_bullet_slide(slide,
    "Disadvantages of USG-Guided Regional Blocks",
    [
        "Significant learning curve — requires dedicated training in both ultrasound physics and image interpretation.",
        "Common novice errors include advancing the needle without visualization and unintentional probe movement.",
        "Equipment cost is substantial; high-quality portable machines may not be available in all settings.",
        "Image quality is reduced in obese patients, heavily calcified tissues, or with deep target nerves.",
        "USG alone cannot prevent all complications — intraneural injection can still occur if not recognized promptly.",
    ],
    subtitle="Limitations to Recognize and Address")

# ───────────────────────────────────────────────────────────
# SLIDE 12 – TECHNICAL LIMITATIONS
# ───────────────────────────────────────────────────────────
slide = prs.slides.add_slide(blank)
add_bullet_slide(slide,
    "Technical Limitations & Artifacts",
    [
        "Anisotropy causes nerve brightness to change with probe angle — the nerve may appear invisible at certain angles.",
        "Acoustic shadowing from bone or calcified structures can obscure underlying nerves.",
        "The bayonet artifact (apparent needle bending) results from heterogeneities in tissue speed of sound.",
        "Reverberation artifacts produce false echoes deep to reflectors, potentially misidentifying structures.",
        "Low-frequency transducers may not adequately reflect echoes from textured echogenic needle surfaces.",
    ],
    subtitle="Understanding Ultrasound Artifacts in Regional Anesthesia")

# ───────────────────────────────────────────────────────────
# SLIDE 13 – COMPARISON TABLE (two-column)
# ───────────────────────────────────────────────────────────
slide = prs.slides.add_slide(blank)
add_two_column_slide(slide,
    "USG vs. Nerve Stimulator — At a Glance",
    "✔  USG Advantages",
    [
        "Real-time nerve & needle visualization",
        "Detects adjacent vessels (Doppler)",
        "Lower local anesthetic volumes needed",
        "Identifies anatomical variants",
        "Guides fascial plane & catheter blocks",
    ],
    "✖  Nerve Stimulator Limitations",
    [
        "No direct visualization of nerve",
        "Cannot confirm LA spread",
        "Higher risk of vascular puncture",
        "Low current may still be intraneural",
        "Cannot detect anatomical anomalies",
    ])

# ───────────────────────────────────────────────────────────
# SLIDE 14 – TRAINING & COMPETENCY
# ───────────────────────────────────────────────────────────
slide = prs.slides.add_slide(blank)
add_bullet_slide(slide,
    "Training & Competency in USG Regional Anesthesia",
    [
        "The six-step learning model covers anatomy, USG physics, transducer handling, phantom practice, clinical supervision, and independent practice.",
        "Step 1: Translate anatomical knowledge into sono-anatomy to create an imaging roadmap.",
        "Step 4 (most important): Tissue-equivalent phantom training coordinates eye, hand, probe, needle, and image simultaneously.",
        "Advancing a needle without visualization is the most dangerous error made by novices.",
        "Standardized teaching programs, workshops, and certification guidelines exist to ensure safe competency.",
    ],
    subtitle="The Six-Step Learning Model")

# ───────────────────────────────────────────────────────────
# SLIDE 15 – CONCLUSION / KEY TAKEAWAYS
# ───────────────────────────────────────────────────────────
slide = prs.slides.add_slide(blank)
add_rect(slide, 0, 0, 13.333, 7.5, BG_DARK)
add_rect(slide, 0, 0, 0.12, 7.5, ACCENT)
add_rect(slide, 0.12, 0, 13.22, 1.3, BG_MID)
add_textbox(slide, "Key Takeaways", 0.35, 0.1, 12.6, 1.1,
            font_size=28, bold=True, color=WHITE)

points = [
    "Ultrasound guidance has transformed regional anesthesia by enabling real-time nerve, needle, and injectate visualization.",
    "Major advantages: higher success rates, improved safety, LA volume sparing, and detection of anatomical variants.",
    "Key disadvantages: steep learning curve, equipment cost, artifact-related errors, and depth/obesity limitations.",
    "Combining USG with nerve stimulation may further improve safety in complex or deep blocks.",
    "Adequate training, structured education, and phantom practice are essential before independent clinical application.",
]

tb = slide.shapes.add_textbox(Inches(0.5), Inches(1.55), Inches(12.3), Inches(5.6))
tf = tb.text_frame
tf.word_wrap = True
tf.auto_size = None
for i, pt in enumerate(points):
    p = tf.paragraphs[0] if i == 0 else tf.add_paragraph()
    p.space_before = Pt(8)
    r0 = p.add_run()
    r0.text = f"{i+1}.  "
    r0.font.size  = Pt(17)
    r0.font.color.rgb = GOLD
    r0.font.bold  = True
    r0.font.name  = "Calibri"
    r1 = p.add_run()
    r1.text = pt
    r1.font.size  = Pt(17)
    r1.font.color.rgb = WHITE
    r1.font.name  = "Calibri"

add_textbox(slide,
    "Source: Miller's Anesthesia, 10th Edition | Morgan & Mikhail's Clinical Anesthesiology, 7th Edition",
    0.5, 7.05, 12.333, 0.35,
    font_size=11, italic=True, color=ACCENT2, align=PP_ALIGN.CENTER)

# ───────────────────────────────────────────────────────────
# SAVE
# ───────────────────────────────────────────────────────────
out_path = "/tmp/workspace/usg-regional-blocks/USG_Regional_Blocks.pptx"
buf = BytesIO()
prs.save(buf)
with open(out_path, "wb") as f:
    f.write(buf.getvalue())
print(f"Saved: {out_path}")
print(f"Slides: {len(prs.slides)}")