# tien-kiem-cua.ps1 - GD-3 khoan (iv): tien kiem chi phi ~0 o DAU MOI CUA.
#
# Chi DOC. KHONG ghi. LUON exit 0 - day la lop INFORM, KHONG phai cong chan.
# Cong chan bang ma loi = W3b (khoan C3-04 + thang 4 trang thai), dang cho owner (P1).
# Ai sua file nay de tra ma != 0 la da doi lop, phai qua W3b truoc.
#
# Vi sao KHONG tin mtime cua he dieu hanh:
#   hook 'wal:' cham tep o bien moi luot, va 'git checkout' viet lai mtime hang loat.
#   mtime tra loi "tep bi cham luc nao", KHONG tra loi "cua dong luc nao".
#   => chon cua bang DAU THOI GIAN GHI TRONG TEP (hub: phu-luc GD-3 khoan (iv)).
#
# Guard vang tep = VI TU MAY (khoan (vii)): Test-Path roi bo qua VA KHAI.
#   CAM dung menh de "cai do chua lam" - menh de do sai ngay giay tep kia ha canh.
#
# A2 (mat ca tap): het nguon => in co THIEU-TAP RIENG, KHONG in "ok".
#   So 0 khong duoc phep doc thanh "sach".
#
# Dung: powershell -NoProfile -ExecutionPolicy Bypass -File scripts/tien-kiem-cua.ps1
#       -Cua adap-apply            (ten cua dang mo - chi de in kem, khong doi hanh vi)
#       -RepoRoot <path>           (fault-inject tren cay tam)

param(
    [string]$Cua = '',
    [string]$RepoRoot = ''
)

$ErrorActionPreference = 'Stop'

function Get-RepoRoot {
    param([string]$Explicit)
    if ($Explicit -and $Explicit.Trim().Length -gt 0) { return $Explicit }
    return (Resolve-Path (Join-Path $PSScriptRoot '..')).Path
}

# Rut dau thoi gian GHI TRONG TEP cua WAL (cua dung: /pause, /snapshot, hook wal:).
# Khuon: "updated: YYYY-MM-DD | session: S<n> ..."
function Read-WalStamp {
    param([string]$Root)
    $p = Join-Path $Root '.claude/WAL.md'
    if (-not (Test-Path -LiteralPath $p)) { return $null }
    # chi doc 10 dong dau - re, va moc luon nam o dau tep
    $head = Get-Content -LiteralPath $p -TotalCount 10 -ErrorAction Stop
    foreach ($line in $head) {
        $m = [regex]::Match($line, 'updated:\s*(\d{4}-\d{2}-\d{2})')
        if ($m.Success) {
            $s = [regex]::Match($line, 'session:\s*(S\d+)')
            return [pscustomobject]@{
                Nguon   = 'WAL'
                Ngay    = $m.Groups[1].Value
                Phien   = $(if ($s.Success) { $s.Groups[1].Value } else { '?' })
            }
        }
    }
    return $null
}

# Rut dau thoi gian GHI TRONG TEP cua so dem phien (cua dung: /session-start, /session-end).
function Read-CounterStamp {
    param([string]$Root)
    $p = Join-Path $Root '.claude/governance/.session-counter.json'
    if (-not (Test-Path -LiteralPath $p)) { return $null }
    $raw = Get-Content -LiteralPath $p -Raw -ErrorAction Stop
    $j = $raw | ConvertFrom-Json
    $ngay = $j.last_ticked_at
    if (-not $ngay) { return $null }
    if ($ngay -notmatch '^\d{4}-\d{2}-\d{2}$') { return $null }
    $phien = $j.last_ticked_session
    if (-not $phien) { $phien = '?' }
    return [pscustomobject]@{
        Nguon = 'counter'
        Ngay  = $ngay
        Phien = "$phien"
    }
}

try {
    $root = Get-RepoRoot -Explicit $RepoRoot
    $nhan = ''
    if ($Cua -and $Cua.Trim().Length -gt 0) { $nhan = " cua=$Cua" }

    $nguon = @()
    $hong  = @()

    foreach ($fn in @('Read-WalStamp', 'Read-CounterStamp')) {
        $r = $null
        try { $r = & $fn -Root $root } catch { $r = $null }
        if ($null -ne $r) { $nguon += $r } else { $hong += $fn }
    }

    # A2 - mat CA TAP: khong con nguon nao doc duoc.
    # In co RIENG, tuyet doi khong in "ok". So 0 mat quyen doc thanh "sach".
    if ($nguon.Count -eq 0) {
        Write-Output "TIEN-KIEM:$nhan THIEU-TAP - 0/2 nguon moc doc duoc (WAL.md + .session-counter.json) | KHONG ket luan duoc gi | (khong chan)"
        exit 0
    }

    # chon cua dong GAN NHAT theo dau thoi gian TRONG TEP (khong phai mtime)
    $moi = $nguon | Sort-Object -Property Ngay -Descending | Select-Object -First 1

    $co = @()
    if ($hong.Count -gt 0) {
        $ten = ($hong -join ',') -replace 'Read-|Stamp', ''
        $co += "NGUON-HONG:$ten"
    }

    # lech phien giua 2 nguon = dau hieu mot dau cua khong dong
    if ($nguon.Count -ge 2) {
        $pset = @($nguon | ForEach-Object { $_.Phien } | Sort-Object -Unique)
        if ($pset.Count -gt 1) { $co += ("LECH-PHIEN:" + ($pset -join '/')) }
    }

    $trangthai = $(if ($co.Count -eq 0) { 'ok' } else { ($co -join ' ') })

    Write-Output ("TIEN-KIEM:$nhan cua-dong-gan-nhat={0} moc-trong-tep={1} phien={2} | nguon {3}/2 | {4}" -f `
        $moi.Nguon, $moi.Ngay, $moi.Phien, $nguon.Count, $trangthai)
    exit 0
}
catch {
    # fail-soft, y nguyen khuon nhip-no-probe: mot buoc MOI khong bao gio duoc lam hong nghi thuc dang chay tot
    Write-Output "tien-kiem loi (khong chan)"
    exit 0
}