"""PinMAP data validator.

Validates a parsed PinMAP for structural and data integrity:
  1. Pin-number uniqueness
  2. Pin-number continuity (1..N with no gaps)
  3. Missing PinName detection (warning, defaults to "NC")
  4. Rectangular-structure sanity

Usage
-----
>>> from validator import validate_pinmap
>>> result = validate_pinmap(pinmap)
>>> if result.is_valid:
...     print("All good")
... else:
...     for e in result.errors:
...         print(f"[ERROR] {e.message}: {e.details}")
"""

from collections import Counter

from models import PinMAP, ValidationResult, ValidationError


def validate_pinmap(pinmap: PinMAP) -> ValidationResult:
    """Validate a PinMAP and return a ValidationResult.

    Checks performed
    ----------------
    1. **Uniqueness** — every pin number must appear exactly once.
    2. **Continuity** — pin numbers must form the sequence 1, 2, …, N
       with no gaps.
    3. **PinName completeness** — pins with empty / whitespace-only names
       generate a *warning* (they will default to "NC" in the output).
    4. **Structure** — width and height must each be ≥ 2.

    Parameters
    ----------
    pinmap : PinMAP
        A pin map produced by ``pinmap_parser.parse_pinmap``.

    Returns
    -------
    ValidationResult
    """
    result = ValidationResult(is_valid=True, errors=[], warnings=[])

    numbers = [p.number for p in pinmap.pins]

    # ── 1. Uniqueness ────────────────────────────────────────────
    if len(numbers) != len(set(numbers)):
        counts = Counter(numbers)
        duplicates = sorted(n for n, c in counts.items() if c > 1)
        result.errors.append(ValidationError(
            level="error",
            message="Pin序号重复",
            details=f"重复的序号: {duplicates}",
        ))

    # ── 2. Continuity ────────────────────────────────────────────
    if numbers:
        expected = set(range(1, max(numbers) + 1))
        actual = set(numbers)
        missing = expected - actual
        if missing:
            result.errors.append(ValidationError(
                level="error",
                message="Pin序号不连续",
                details=f"缺失的序号: {sorted(missing)}",
            ))

    # ── 3. PinName completeness ──────────────────────────────────
    missing_names = [
        p for p in pinmap.pins
        if not p.name or not p.name.strip()
    ]
    if missing_names:
        result.warnings.append(ValidationError(
            level="warning",
            message=(
                f"检测到 {len(missing_names)} 个引脚缺少 PinName"
            ),
            details=(
                f"缺失引脚序号: {[p.number for p in missing_names]}，"
                f"将默认为 NC"
            ),
        ))

    # ── 4. Structure sanity ──────────────────────────────────────
    if pinmap.width < 2 or pinmap.height < 2:
        result.errors.append(ValidationError(
            level="error",
            message="方形结构不完整",
            details=(
                f"尺寸: {pinmap.width}x{pinmap.height}，至少需要 2x2"
            ),
        ))

    # ── Final verdict ────────────────────────────────────────────
    if result.errors:
        result.is_valid = False

    return result


def validate_pinlist_for_map(
    entries: list,
    rows: int,
    cols: int,
) -> ValidationResult:
    """验证 PinList 数据是否适合转换为 PinMAP。

    Checks performed
    ----------------
    1. **Continuity** — pin numbers must start from 1 with no gaps.
    2. **Uniqueness** — no duplicate pin numbers.
    3. **Perimeter match** — total pin count must equal
       (rows + cols) × 2 (the grid perimeter).
    4. **Non-multiple-of-4** — if pin count is not a multiple of 4,
       a warning is issued (but conversion is not blocked).

    Parameters
    ----------
    entries : list[PinListEntry]
        PinList entries, each with ``number`` and ``name`` attributes.
    rows : int
        Target PinMAP row count.
    cols : int
        Target PinMAP column count.

    Returns
    -------
    ValidationResult
    """
    result = ValidationResult(is_valid=True, errors=[], warnings=[])

    numbers = [e.number for e in entries]

    # ── 1. Continuity (1..N, no gaps) ────────────────────────────
    expected_numbers = list(range(1, len(numbers) + 1))
    if numbers != expected_numbers:
        missing = set(expected_numbers) - set(numbers)
        if missing:
            result.errors.append(ValidationError(
                level="error",
                message="Pin序号不连续",
                details=f"缺失的序号: {sorted(missing)}",
            ))

    # ── 2. Uniqueness ────────────────────────────────────────────
    if len(numbers) != len(set(numbers)):
        counts = Counter(numbers)
        duplicates = sorted(n for n, c in counts.items() if c > 1)
        result.errors.append(ValidationError(
            level="error",
            message="Pin序号存在重复",
            details=f"重复的序号: {duplicates}",
        ))

    # ── 3. Perimeter match ───────────────────────────────────────
    # 周长公式：(rows + cols) * 2
    expected_total = (rows + cols) * 2
    actual_total = len(entries)
    if actual_total != expected_total:
        result.errors.append(ValidationError(
            level="error",
            message="Pin数量与网格周长不匹配",
            details=(
                f"网格 {rows}×{cols} 需要 {expected_total} 个引脚，"
                f"但 PinList 有 {actual_total} 个"
            ),
        ))

    # ── 4. Non-multiple-of-4 warning ─────────────────────────────
    if actual_total % 4 != 0:
        result.warnings.append(ValidationError(
            level="warning",
            message="Pin数量不是4的倍数",
            details=(
                f"Pin数量 ({actual_total}) 不是 4 的倍数，"
                f"四条边将不均匀分布"
            ),
        ))

    # ── Final verdict ────────────────────────────────────────────
    if result.errors:
        result.is_valid = False

    return result