#!/usr/bin/env python3
"""Programmatic visual review of screenshots: OCR geometry, contrast, palette, composition."""
import sys, subprocess, csv, io, math
from PIL import Image
import numpy as np

SHOTS = sys.argv[1:]
LANG = "eng+chi_sim"

def rel_lum(arr):
    a = arr.astype(np.float64) / 255.0
    def f(c): return np.where(c <= 0.03928, c / 12.92, ((c + 0.055) / 1.055) ** 2.4)
    return 0.2126 * f(a[..., 0]) + 0.7152 * f(a[..., 1]) + 0.0722 * f(a[..., 2])

def cr(l1, l2):
    hi, lo = max(l1, l2), min(l1, l2)
    return (hi + 0.05) / (lo + 0.05)

def hexc(rgb):
    return "#%02x%02x%02x" % tuple(int(x) for x in rgb)

def ocr_lines(img_path):
    """Return list of (text, x,y,w,h, conf) grouped per line."""
    p = subprocess.run(
        ["tesseract", img_path, "stdout", "-l", LANG, "--psm", "11", "tsv"],
        capture_output=True, text=True)
    rows = list(csv.DictReader(io.StringIO(p.stdout), delimiter="\t"))
    lines = {}
    for r in rows:
        try:
            conf = float(r["conf"])
        except Exception:
            continue
        if conf < 35 or not r["text"].strip():
            continue
        key = (r["block_num"], r["par_num"], r["line_num"])
        e = lines.setdefault(key, {"words": [], "x0": 10**9, "y0": 10**9, "x1": -1, "y1": -1, "confs": []})
        x, y, w, h = int(r["left"]), int(r["top"]), int(r["width"]), int(r["height"])
        e["words"].append((r["text"], conf))
        e["confs"].append(conf)
        e["x0"] = min(e["x0"], x); e["y0"] = min(e["y0"], y)
        e["x1"] = max(e["x1"], x + w); e["y1"] = max(e["y1"], y + h)
    out = []
    for k in sorted(lines, key=lambda k: (lines[k]["y0"], lines[k]["x0"])):
        e = lines[k]
        out.append({"text": " ".join(w for w, _ in e["words"]),
                    "bbox": (e["x0"], e["y0"], e["x1"] - e["x0"], e["y1"] - e["y0"]),
                    "conf": sum(e["confs"]) / len(e["confs"])})
    return out

def analyze(path):
    im = Image.open(path).convert("RGB")
    W, H = im.size
    arr = np.asarray(im)
    L = rel_lum(arr)
    gray = np.asarray(im.convert("L"))

    print(f"\n{'='*78}\n{path}  ({W}x{H})\n{'='*78}")

    # Global tone
    print(f"luminance mean={L.mean():.3f} p5={np.percentile(L,5):.3f} p50={np.percentile(L,50):.3f} "
          f"p95={np.percentile(L,95):.3f} | dark(<0.15)={100*(L<0.15).mean():.0f}% bright(>0.85)={100*(L>0.85).mean():.0f}%")

    # Palette
    q = im.quantize(colors=8, method=Image.Quantize.MEDIANCUT)
    pal = q.getpalette()
    counts = sorted(q.getcolors(W * H), reverse=True)
    tot = W * H
    tops = []
    for cnt, idx in counts[:8]:
        rgb = pal[idx*3:idx*3+3]
        tops.append(f"{hexc(rgb)} {100*cnt/tot:.0f}%")
    print("palette: " + "  ".join(tops))

    # Composition grid: 16 cols x 10 rows -> mean luminance (0-9) and dominant hue class letter
    GX, GY = 16, 10
    print("composition grid (mean lum 0-9; hue: R=red/warm Y=yellow/tan G=green C=cyan B=blue M=magenta K=neutral-dark N=neutral-mid W=white-ish):")
    hsv = np.asarray(im.convert("HSV")).astype(int)
    hh, ss, vv = hsv[..., 0], hsv[..., 1], hsv[..., 2]
    for gy in range(GY):
        row = ""
        for gx in range(GX):
            cell = L[gy*H//GY:(gy+1)*H//GY, gx*W//GX:(gx+1)*W//GX]
            m = cell.mean()
            # dominant hue of saturated pixels
            ch = hh[gy*H//GY:(gy+1)*H//GY, gx*W//GX:(gx+1)*W//GX]
            cs = ss[gy*H//GY:(gy+1)*H//GY, gx*W//GX:(gx+1)*W//GX]
            sat = cs > 60
            if m > 0.85: c = "W"
            elif sat.mean() > 0.12:
                ang = np.median(ch[sat]) * 360 / 255
                c = "R" if ang < 25 or ang >= 330 else "Y" if ang < 70 else "G" if ang < 160 else "C" if ang < 200 else "B" if ang < 270 else "M"
            elif m > 0.45: c = "N"
            else: c = "K"
            row += str(min(9, int(m * 10))) + c
        print("  " + row)

    # Low-variance (flat) regions — candidate dead space
    flat = []
    for gy in range(GY):
        for gx in range(GX):
            cell = gray[gy*H//GY:(gy+1)*H//GY, gx*W//GX:(gx+1)*W//GX]
            if cell.std() < 6:
                flat.append((gx, gy, round(float(cell.mean()))))
    print(f"flat cells (std<6): {len(flat)}/{GX*GY}" + (f" at {flat[:12]}" if flat else ""))

    # OCR line analysis
    lines = ocr_lines(path)
    print(f"OCR: {len(lines)} lines (conf>=35)")
    low_contrast, overlaps, tiny = [], [], []
    boxes = []
    for ln in lines:
        x, y, w, h = ln["bbox"]
        if w <= 1 or h <= 1 or x < 0 or y < 0 or x + w > W or y + h > H:
            continue
        pad = 2
        x0, y0 = max(0, x - pad), max(0, y - pad)
        x1, y1 = min(W, x + w + pad), min(H, y + h + pad)
        reg = L[y0:y1, x0:x1]
        lo, hi = np.percentile(reg, 5), np.percentile(reg, 95)
        ratio = cr(hi, lo)
        boxes.append((x, y, w, h, ln["text"]))
        if h < 9 and ln["conf"] > 50:
            tiny.append(ln)
        if ratio < 4.0 and len(ln["text"].strip()) > 1:
            low_contrast.append((ln["text"][:40], (x, y, w, h), round(ratio, 2)))
    # overlap between different lines (>25% of smaller area)
    for i in range(len(boxes)):
        for j in range(i + 1, len(boxes)):
            ax, ay, aw, ah, at = boxes[i]; bx, by, bw, bh, bt = boxes[j]
            ox = max(0, min(ax+aw, bx+bw) - max(ax, bx)); oy = max(0, min(ay+ah, by+bh) - max(ay, by))
            inter = ox * oy
            small = min(aw*ah, bw*bh)
            if small and inter / small > 0.30 and at != bt:
                overlaps.append((at[:28], bt[:28], round(100*inter/small)))
    if low_contrast:
        print("LOW CONTRAST (<4:1):")
        for t, b, r in low_contrast[:14]:
            print(f"   {r:>5}:1  @({b[0]},{b[1]},{b[2]}x{b[3]})  '{t}'")
        if len(low_contrast) > 14: print(f"   ... +{len(low_contrast)-14} more")
    else:
        print("LOW CONTRAST: none flagged")
    if overlaps:
        print("OVERLAPPING TEXT BOXES:")
        for a, b, pct in overlaps[:10]:
            print(f"   {pct}%  '{a}'  vs  '{b}'")
    if tiny:
        print(f"VERY SMALL TEXT (<9px tall): {len(tiny)} e.g. " + "; ".join(t['text'][:18] for t in tiny[:5]))

    # Print all OCR lines with geometry so reviewer can reconstruct layout
    print("--- OCR transcript (x,y w h | conf | text) ---")
    for ln in lines:
        x, y, w, h = ln["bbox"]
        print(f"   ({x:>4},{y:>4} {w:>4}x{h:<3}|{ln['conf']:.0f}) {ln['text'][:90]}")

for p in SHOTS:
    try:
        analyze(p)
    except Exception as e:
        print(f"\nFAILED {p}: {type(e).__name__}: {e}")