#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""mermaid 代码块语法预检（提交门禁：mermaid-syntax）

为什么要有（2026-10-30 接线）：
    docs/子系统设计/屏板链路设计说明.md §1 的 flowchart 里一行带文字点线写成了
    `S -.|"..."| T`（合法形态是 `-.->|"..."|` 或 `-. 文字 .->`，`-.|` 不是箭头
    token），mermaid 渲染 `Syntax error in text`。该图自 2026-10-29 落库起就是坏的，
    doc-links 等文档门禁全绿也拦不住——因为它们查链接与章节，**不查围栏内图表语法**。
    本闸只查围栏内的确定性形态，不重造 mermaid 解析器。

查什么（v1 三条，都是「错了必渲染失败」的确定性形态）：
    R1 图类型头：```mermaid 后首个非空行必须以已知图类型关键字开头
       （flowchart/graph/sequenceDiagram/stateDiagram.../classDiagram/erDiagram/
        gantt/journey/pie/mindmap/timeline/quadrantChart/gitGraph/C4Context...）。
       没有头的块 100% 渲染失败。
    R2 `-.` 后直接跟管道（本坑形态）：`-.` + 空白 + `|` 不是任何合法箭头；
       带文字点线的合法形态只有 `-.->|t|`、`-.-|t|`? 没有、以及 `-. t .->`。
       （`-.->` 在 `-.` 后是 `>`，`-. t .->` 在 `-.` 后是空白+文字再 `.->`，
         故本判据不误伤这两种——见 --selftest T2。）
    R3 容器配对：flowchart/graph 的 `subgraph` 行数 == 独占一行的 `end` 行数；
       sequenceDiagram 的行首块起点（alt/opt/loop/par/critical/rect/break）行数
       == 行首 `end` 行数（else/and/option 是分支不消费 end）。缺一边必渲染失败。

增量拦截（照 bom-guard / bsp-err / nested-comment 先例，只减不增）：
    存量钉在 BASELINE（按 文件 + 规则 + 上下文指纹 计数，不按行号）；
    基线之外的新命中 → 退出码 1。还清某条就删那一行，--prune 打台账。

用法：
    python scripts/check_mermaid.py [files...]     # 钩子模式（喂暂存的 md）
    python scripts/check_mermaid.py --all          # 全仓自查（口径 = 钩子实际会喂的文件集）
    python scripts/check_mermaid.py --prune        # 打基线台账 + 点名已还清可删的行
    python scripts/check_mermaid.py --selftest     # 自证五条

排除面（与 doc-links 同口径，见 .pre-commit-config.yaml 的 exclude）：
    芯片手册转录（外部资料，围栏形态不受控）与第三方目录整体不进语料。
"""
import argparse
import pathlib
import re
import sys

REPO = pathlib.Path(__file__).resolve().parent.parent

# 与钩子 exclude 一致：这些前缀下的 md 不进语料
EXCLUDE_PREFIXES = (
    ".opencode/node_modules/",
    "Lib/lvgl/",
    "MDK-ARM/RTE/",
    "docs/芯片手册/",
)

DIAGRAM_HEADS = (
    "flowchart", "graph", "sequenceDiagram", "stateDiagram", "stateDiagram-v2",
    "classDiagram", "erDiagram", "gantt", "journey", "pie", "mindmap",
    "timeline", "quadrantChart", "xychart-beta", "gitGraph", "requirementDiagram",
    "C4Context", "C4Container", "C4Component", "packet", "block-beta", "kanban",
    "architecture-beta", "radar", "treemap", "sankey-beta", "wardley",
)
RE_FENCE_OPEN = re.compile(r"^\s*```\s*mermaid\s*$")
RE_FENCE_CLOSE = re.compile(r"^\s*```\s*$")
# R2：`-.` 后（允许空白）直接出现管道 = 非法箭头 + 管道文字（本坑形态 `-.|"t"|`）
RE_BAD_DOT_PIPE = re.compile(r"-\.(\s*\|)")
# R3 用：行首关键字
RE_SUBGRAPH = re.compile(r"^\s*subgraph\b")
RE_END_LINE = re.compile(r"^\s*end\b\s*(\[\s*\])?\s*$")
RE_SEQ_BLOCK_START = re.compile(r"^\s*(alt|opt|loop|par|critical|rect|break)\b")
RE_SEQ_END = re.compile(r"^\s*end\b")
RE_COMMENT = re.compile(r"^\s*(%%|rem\b|#)")


def iter_blocks(lines):
    """产出 (fence_line_no_1based, [block lines])。围栏未闭合也报（当空块+坏）。"""
    i = 0
    n = len(lines)
    while i < n:
        m = RE_FENCE_OPEN.match(lines[i])
        if not m:
            i += 1
            continue
        start = i
        j = i + 1
        while j < n and not RE_FENCE_CLOSE.match(lines[j]):
            j += 1
        yield start + 1, lines[start + 1:j], j < n
        i = j + 1


def diagram_head(block):
    for ln in block:
        if not ln.strip() or RE_COMMENT.match(ln):
            continue
        return ln.strip()
    return ""


def hits_for_block(lines, offset):
    """返回 [(abs_line_1based, rule, 上下文指纹)]"""
    hits = []
    head = diagram_head(lines)
    if not head:
        hits.append((offset, "R1-no-head", "nohead"))
    elif not head.startswith(DIAGRAM_HEADS):
        first = re.split(r"[\s\[({]", head, 1)[0]
        hits.append((offset, "R1-bad-head", "head:" + first))
    is_flow = head.startswith(("flowchart", "graph"))
    is_seq = head.startswith("sequenceDiagram")
    sg = en = sb = se = 0
    for k, raw in enumerate(lines):
        ln = raw
        if RE_COMMENT.match(ln):
            continue
        if RE_BAD_DOT_PIPE.search(ln):
            ctx = "dotpipe:" + re.sub(r"\s+", " ", ln.strip())[:80]
            hits.append((offset + k + 1, "R2-dot-pipe", ctx))
        if RE_SUBGRAPH.match(ln):
            sg += 1
        elif RE_END_LINE.match(ln):
            en += 1
        if is_seq:
            if RE_SEQ_BLOCK_START.match(ln) and not RE_SEQ_END.match(ln):
                sb += 1
            elif RE_SEQ_END.match(ln):
                se += 1
    if is_flow:
        lo = min(sg, en)
        for _ in range(abs(sg - en)):
            hits.append((offset, "R3-subgraph-end",
                         "pair:sg=%d,end=%d" % (sg, en)))
    if is_seq:
        for _ in range(abs(sb - se)):
            hits.append((offset, "R3-seq-end",
                         "pair:blk=%d,end=%d" % (sb, se)))
    return hits


def scan_text(text):
    hits = []
    lines = text.splitlines()
    for start_no, block, closed in iter_blocks(lines):
        if not closed:
            hits.append((start_no, "R0-unclosed-fence", "unclosed"))
        hits.extend(hits_for_block(block, start_no))
    return hits


def check_file(path):
    """path: pathlib.Path（相对仓库根）。返回 (blocks数, [(abs_line, rule, ctx)]) 或 None（跳过）。"""
    try:
        text = path.read_text(encoding="utf-8")
    except (UnicodeDecodeError, OSError) as e:
        print("  [skip] %s（%s）" % (path, e))
        return None
    return count_and_hits(text)


def count_and_hits(text):
    hits = []
    lines = text.splitlines()
    nblk = 0
    for start_no, block, closed in iter_blocks(lines):
        nblk += 1
        if not closed:
            hits.append((start_no, "R0-unclosed-fence", "unclosed"))
        hits.extend(hits_for_block(block, start_no))
    return nblk, hits


# ---------------------------------------------------------------- 基线与报告
# 存量基线（接线当天 2026-10-30 --all 实扫钉入，只减不增；还清删行，--prune 点名）：
BASELINE = (
)


def fingerprint(rel, rule, ctx):
    # 上下文指纹不逐字节钉死（改图会漂移）：R3 的 pair 数字归一化
    if rule.startswith("R3"):
        return rel + "|" + rule + "|pair"
    return rel + "|" + rule + "|" + ctx


def collect_baseline():
    d = {}
    for rel, rule, ctx in BASELINE:
        key = fingerprint(rel, rule, ctx)
        d[key] = d.get(key, 0) + 1
    return d


def all_md_files():
    out = []
    for p in REPO.rglob("*.md"):
        rel = p.relative_to(REPO).as_posix()
        if any(rel.startswith(pre) for pre in EXCLUDE_PREFIXES):
            continue
        if "/node_modules/" in ("/" + rel) or "/.git/" in ("/" + rel):
            continue
        out.append(p)
    return sorted(out)


def report(files, show_baseline=False, prune=False):
    base = collect_baseline()
    consumed = dict(base)
    new_hits = []
    files_with = 0
    blocks = 0
    for p in files:
        rel = p.relative_to(REPO).as_posix()
        r = check_file(p)
        if r is None or r[0] == 0:
            continue
        nblk, hits = r
        files_with += 1
        blocks += nblk
        for (ln, rule, ctx) in hits:
            key = fingerprint(rel, rule, ctx)
            if consumed.get(key, 0) > 0:
                consumed[key] -= 1
            else:
                new_hits.append((rel, ln, rule, ctx))
    print("mermaid 预检：%d 个文件共 %d 块围栏，新发 %d 处，基线在册 %d 处"
          % (files_with, blocks, len(new_hits), sum(base.values())))
    if new_hits:
        print("\n--- 新发（不被基线吞）---")
        for (rel, ln, rule, ctx) in new_hits:
            print("  %s:%d  [%s] %s" % (rel, ln, rule, ctx))
        print("\n判读：R1=缺图类型头；R2=`-.` 后直接跟 `|`（改 `-.->|` 或 `-. t .->`）；"
              "R3=subgraph/块起点与独占行 end 不配对；R0=围栏未闭合。")
    if prune or (show_baseline and base):
        print("\n--- 存量基线台账（只减不增）---")
        for (rel, rule, ctx) in BASELINE:
            left = consumed.get(fingerprint(rel, rule, ctx), 0)
            mark = "已还清，可删" if left == 0 else "仍占 %d" % left
            print("  %-70s [%s] %s" % (rel, rule, mark))
    if prune:
        restorable = [b for b in BASELINE
                      if consumed.get(fingerprint(*b), 0) == 0]
        if restorable:
            print("\n[TIGHTEN] 基线 %d 条本轮实测已还清，可下架：%s"
                  % (len(restorable), restorable))
    return 1 if new_hits else 0


# ---------------------------------------------------------------- selftest
def selftest():
    ok = True
    def scan(text):
        return scan_text(text)

    # T1 正例：合法 flowchart（含 `-.->|` 与 `-. t .->` 两种合法点线）+ sequence 配对
    good = (
        "```mermaid\nflowchart TB\n"
        '  A["甲"] -->|"有字"| B["乙"]\n'
        "  A -.->|点线有字| B\n"
        "  A -. 点线文字 .-> B\n"
        "  subgraph SG[\"组\"]\n    B --> C[\"丙\"]\n  end\n"
        "```\n")
    h = [x for x in scan(good) if x[1] != "R0-unclosed-fence" or True]
    print("  T1 正例（含三种合法点线 + 配对 subgraph）→ 命中 %d（要求 0）" % len(h))
    ok &= (len(h) == 0)

    # T2 本坑形态必响，合法形态不误伤
    bad = "```mermaid\nflowchart TB\n  S -.|\"文字\"| T\n```\n"
    h = [x for x in scan(bad) if x[1] == "R2-dot-pipe"]
    print("  T2 本坑 `-.|\"..\"|` → R2 命中 %d（要求 1）" % len(h))
    ok &= (len(h) == 1)

    # T3 subgraph 缺 end 必响
    bad3 = "```mermaid\nflowchart LR\n  subgraph X[\"x\"]\n    A-->B\n```\n"
    h = [x for x in scan(bad3) if x[1].startswith("R3-subgraph")]
    print("  T3 subgraph 无 end → R3 命中 %d（要求 1）" % len(h))
    ok &= (len(h) == 1)

    # T4 缺图类型头必响；sequence 配对不误伤
    bad1 = "```mermaid\nflowChat TB\n  A-->B\n```\n"
    h = [x for x in scan(bad1) if x[1] == "R1-bad-head"]
    gseq = ("```mermaid\nsequenceDiagram\n  participant A\n  alt 条件\n    A->>A: x\n"
            "  else 其他\n    A->>A: y\n  end\n```\n")
    h2 = scan(gseq)
    print("  T4 假头必响 %d（要求 1）/ sequence alt-else-end 不误伤 %d（要求 0）"
          % (len(h), len(h2)))
    ok &= (len(h) == 1 and len(h2) == 0)

    # T5 基线吞得下 + 只减不增有牙
    rel = "fake/file.md"
    hit = scan(bad)[0]
    key_new = fingerprint(rel, hit[1], hit[2])
    b1 = {key_new: 1}
    within = 1 if collect_hit_in(b1, rel, hit) else 0
    b2 = {}
    outside = 0 if collect_hit_in(b2, rel, hit) else 1
    print("  T5 基线在册吞 %d（要求 1）/ 基线清空后同命中算新发 %d（要求 1）"
          % (within, outside))
    ok &= (within == 1 and outside == 1)

    print("SELFTEST:", "PASS" if ok else "FAIL")
    return 0 if ok else 1


def collect_hit_in(base, rel, hit):
    key = fingerprint(rel, hit[1], hit[2])
    return base.get(key, 0) > 0


# ---------------------------------------------------------------- main
def main():
    if hasattr(sys.stdout, "reconfigure"):
        sys.stdout.reconfigure(encoding="utf-8", errors="replace")
    ap = argparse.ArgumentParser(description="mermaid 围栏语法预检（只减不增基线）")
    ap.add_argument("files", nargs="*", help="md 文件（钩子喂暂存文件）")
    ap.add_argument("--all", action="store_true", help="全仓自查（口径=钩子文件集）")
    ap.add_argument("--prune", action="store_true", help="打基线台账并点名已还清行")
    ap.add_argument("--selftest", action="store_true", help="自证五条")
    args = ap.parse_args()

    if args.selftest:
        sys.exit(selftest())

    if args.all:
        files = all_md_files()
    else:
        files = [pathlib.Path(f).resolve() for f in args.files]
        files = [p for p in files
                 if not any(p.relative_to(REPO).as_posix().startswith(pre)
                            for pre in EXCLUDE_PREFIXES)]
    if not files:
        print("mermaid 预检：0 个文件（跳过 = 通过）")
        sys.exit(0)
    sys.exit(report(files, show_baseline=bool(args.all), prune=args.prune))


if __name__ == "__main__":
    main()