body_type_classifier.py

import math

# ===========================
# 男性體型分類
# ===========================
def classify_male_body_type(body_measurements):
    """
    根據胸圍、腰圍、臀圍判斷男生體型：
    回傳其中一個：
        "矩形", "三角形", "倒三角", "梯形", "橢圓形"
    """

    C = body_measurements["chest circumference"]   # 胸圍
    W = body_measurements["waist circumference"]   # 腰圍
    H = body_measurements["hip circumference"]     # 臀圍

    if C <= 0 or W <= 0 or H <= 0:
        raise ValueError("胸圍、腰圍、臀圍必須為正數")

    # 1) 轉成比例（避免整體放大時結果改變）
    total = C + W + H
    pC, pW, pH = C / total, W / total, H / total
    v = (pC, pW, pH)

    # 2) 各體型的「理想比例」（pC, pW, pH）
    ideal_patterns = {
        "矩形":   (0.34, 0.32, 0.34),
        "三角形": (0.32, 0.31, 0.37),
        "倒三角": (0.37, 0.31, 0.32),
        "梯形":   (0.36, 0.31, 0.33),
        "橢圓形": (0.32, 0.36, 0.32),
    }

    # 3) 表格規則的門檻
    def gate_rect(C, W, H):
        # 胸臀差 ≤ 5%，腰比胸臀小
        diff_CH = abs(C - H) / max(C, H)
        return diff_CH <= 0.05 and W <= min(C, H)

    def gate_tri(C, W, H):
        # 三角形（下寬上窄）：臀比胸大 > 10%，且腰比胸臀都小
        return (H >= C * 1.10) and (W <= min(C, H))

    def gate_inv(C, W, H):
        # 倒三角（上寬下窄）：胸比臀大 > 10%，且腰比胸臀都小
        return (C >= H * 1.10) and (W <= min(C, H))

    def gate_trap(C, W, H):
        # 梯形：胸比臀大 5%～10%，腰比胸臀小
        return (C > H * 1.05) and (C <= H * 1.10) and (W <= min(C, H))

    def gate_oval(C, W, H):
        # 橢圓形：腰比胸臀都大 5% 以上
        return (W >= C * 1.05) and (W >= H * 1.05)

    gates = {
        "矩形": gate_rect,
        "三角形": gate_tri,
        "倒三角": gate_inv,
        "梯形": gate_trap,
        "橢圓形": gate_oval,
    }

    def dist(a, b):
        return math.sqrt(
            (a[0] - b[0]) ** 2 +
            (a[1] - b[1]) ** 2 +
            (a[2] - b[2]) ** 2
        )

    # 4) 先找有通過門檻的
    candidates = []
    for name in ideal_patterns.keys():
        if gates[name](C, W, H):
            d = dist(v, ideal_patterns[name])
            candidates.append((d, name))

    if candidates:
        candidates.sort()
        return candidates[0][1]

    # 5) 若完全沒有門檻通過，就純看誰最接近 ideal pattern
    best_name = None
    best_d = float("inf")
    for name, ideal_v in ideal_patterns.items():
        d = dist(v, ideal_v)
        if d < best_d:
            best_d = d
            best_name = name

    return best_name


# ===========================
# 女性體型分類
# ===========================
def classify_female_body_type(body_measurements):
    """
    使用【比例】而不是【公分】來判斷女性體型，並引入 ideal_patterns + 距離判斷：
    - 沙漏型：胸 & 臀 都明顯 > 腰，且胸臀相近
    - 蘋果型：腰明顯 > 臀（且多半 ≥ 胸）
    - 梨型：臀明顯 > 肩寬x2
    - 倒三角型：肩寬x2 明顯 > 臀
    - H 型：胸/腰/臀差距都不大、肩寬x2 與 臀也接近

    回傳：
        "蘋果型", "梨型", "沙漏型", "倒三角型", "H 型"
    """

    C = body_measurements["chest circumference"]   # 胸圍（任意長度單位）
    W = body_measurements["waist circumference"]   # 腰圍
    H = body_measurements["hip circumference"]     # 臀圍
    S = body_measurements["shoulder breadth"]      # 肩寬（寬度，不是圍度）
    shoulders2 = S * 2

    if min(C, W, H, shoulders2) <= 0:
        raise ValueError("胸/腰/臀/肩寬 必須為正數")

    # ========= 1) 轉成比例（不吃單位） =========
    total = C + W + H
    pC, pW, pH = C / total, W / total, H / total
    v = (pC, pW, pH)

    # ========= 2) 各體型的 ideal pattern（比例） =========
    ideal_patterns = {
        "沙漏型":   (0.35, 0.30, 0.35),  # 胸 & 臀大、腰細
        "蘋果型":   (0.32, 0.36, 0.32),  # 腰較大
        "梨型":     (0.32, 0.31, 0.37),  # 臀較大
        "倒三角型": (0.37, 0.31, 0.32),  # 胸較大
        "H 型":     (0.34, 0.32, 0.34),  # 三者接近
    }

    def dist(a, b):
        return math.sqrt(
            (a[0] - b[0]) ** 2 +
            (a[1] - b[1]) ** 2 +
            (a[2] - b[2]) ** 2
        )

    # ========= 3) 定義比例型 gate（門檻） =========
    cw_ratio = (C - W) / W              # 胸比腰大幾%
    hw_ratio = (H - W) / W              # 臀比腰大幾%
    hip_shoulder_diff = (H - shoulders2) / H  # 臀比肩寬x2 大幾%（<0 表肩更寬）

    ch_diff_ratio = abs(C - H) / max(C, H)    # 胸臀接近程度
    w_vs_ch_hip = (W - min(C, H)) / min(C, H) # 腰比胸/臀大多少（判斷蘋果用）

    # 沙漏型 gate：胸 & 臀 都比腰大，且胸臀接近
    def gate_hourglass(C, W, H, shoulders2):
        return (cw_ratio >= 0.25 and hw_ratio >= 0.30 and ch_diff_ratio <= 0.07)

    # 蘋果型 gate：腰明顯 > 臀（通常也 ≥ 胸）
    def gate_apple(C, W, H, shoulders2):
        return (W >= max(C, H)) and ((W - H) / H > 0.03)

    # 梨型 gate：臀明顯 > 肩寬x2（原本「> 3cm」，改成約 3%）
    def gate_pear(C, W, H, shoulders2):
        return hip_shoulder_diff > 0.03

    # 倒三角 gate：肩寬x2 明顯 > 臀
    def gate_inv_tri(C, W, H, shoulders2):
        return hip_shoulder_diff < -0.03

    # H 型 gate：肩寬x2 與 臀差距小，胸臀也跟腰差距不算大
    def gate_h(C, W, H, shoulders2):
        return (
            abs(hip_shoulder_diff) <= 0.03 and
            abs(cw_ratio) <= 0.25 and
            abs(hw_ratio) <= 0.25 and
            w_vs_ch_hip < 0.10   # 腰不會比胸/臀大太多（避免蘋果）
        )

    gates = {
        "沙漏型": gate_hourglass,
        "蘋果型": gate_apple,
        "梨型": gate_pear,
        "倒三角型": gate_inv_tri,
        "H 型": gate_h,
    }

    # ========= 4) 先找「有通過門檻」的體型，裡面選距離最近 =========
    candidates = []
    for name in ideal_patterns.keys():
        if gates[name](C, W, H, shoulders2):
            d = dist(v, ideal_patterns[name])
            candidates.append((d, name))

    if candidates:
        candidates.sort()
        return candidates[0][1]

    # ========= 5) 若完全沒有門檻通過，就純看 ideal pattern 距離 =========
    best_name = None
    best_d = float("inf")
    for name, ideal_v in ideal_patterns.items():
        d = dist(v, ideal_v)
        if d < best_d:
            best_d = d
            best_name = name

    return best_name


# ===========================
# 測試範例
# ===========================
if __name__ == "__main__":
    # === 男性測試資料（用你之前那組） ===
    male_body_measurements = {
        "height": 196.27,
        "shoulder to crotch height": 77.3,
        "arm left length": 55.35,
        "arm right length": 58.13,
        "inside leg height": 81.09,
        "shoulder breadth": 62.82,
        "arm length (shoulder to elbow)": 36.15,
        "crotch height": 83.7,
        "Hip circumference max height": 94.81,
        "arm length (spine to wrist)": 32.54,
        "head circumference": 60.98,
        "neck circumference": 33.72,
        "chest circumference": 150.78,
        "waist circumference": 154.85,
        "hip circumference": 158.92,
        "wrist right circumference": 25.12,
        "bicep right circumference": 39.0,
        "forearm right circumference": 35.64,
        "thigh left circumference": 72.86,
        "calf left circumference": 49.86,
        "ankle left circumference": 29.34
    }

    male_type = classify_male_body_type(male_body_measurements)
    print("男性體型判斷結果：", male_type)

    # === 女性測試資料（先給一組假資料，你之後可以換成實際量測） ===
    female_body_measurements = {
        "height": 165.0,
        "shoulder to crotch height": 60.0,
        "arm left length": 50.0,
        "arm right length": 50.0,
        "inside leg height": 75.0,
        "shoulder breadth": 40.0,          # 肩寬 40 → 肩寬x2 = 80
        "arm length (shoulder to elbow)": 30.0,
        "crotch height": 78.0,
        "Hip circumference max height": 95.0,
        "arm length (spine to wrist)": 30.0,
        "head circumference": 55.0,
        "neck circumference": 33.0,
        "chest circumference": 90.0,       # 胸 90
        "waist circumference": 70.0,       # 腰 70
        "hip circumference": 95.0,         # 臀 95
        "wrist right circumference": 16.0,
        "bicep right circumference": 28.0,
        "forearm right circumference": 24.0,
        "thigh left circumference": 55.0,
        "calf left circumference": 36.0,
        "ankle left circumference": 22.0
    }

    female_type = classify_female_body_type(female_body_measurements)
    print("女性體型判斷結果：", female_type)