# context_watch.ps1 - cat context ocupa sesiunea curenta Claude Code.
# Citeste ultimul "usage" din transcriptul JSONL al sesiunii (input + cache_read + cache_creation).
# Utilizare:
#   - ca hook (PostToolUse): primeste pe stdin JSON-ul hook-ului, cu transcript_path;
#   - manual:  powershell -File context_watch.ps1 [-TranscriptPath <cale.jsonl>] [-Prag 250000]
# Iese cu 2 si scrie pe stderr cand contextul depaseste pragul (asa ajunge mesajul la agent).
[CmdletBinding()]
param(
    [string]$TranscriptPath,
    [int]$Prag = 250000,
    [int]$PragMax = 275000,
    [switch]$Intotdeauna,
    [switch]$Stdout   # UserPromptSubmit: mesajul se scrie pe stdout si se iese cu 0
)

if (-not $TranscriptPath) {
    $stdin = [Console]::In.ReadToEnd()
    if ($stdin) {
        try { $TranscriptPath = (ConvertFrom-Json $stdin).transcript_path } catch { }
    }
}
if (-not $TranscriptPath -or -not (Test-Path $TranscriptPath)) {
    $dir = Join-Path $env:USERPROFILE ".claude\projects\$((Get-Location).Path -replace '[:\\/]','-')"
    if (Test-Path $dir) {
        $f = Get-ChildItem "$dir\*.jsonl" | Sort-Object LastWriteTime -Descending | Select-Object -First 1
        if ($f) { $TranscriptPath = $f.FullName }
    }
}
if (-not $TranscriptPath -or -not (Test-Path $TranscriptPath)) { exit 0 }

# doar coada fisierului - transcriptul poate avea zeci de MB
$fs = [IO.File]::Open($TranscriptPath, 'Open', 'Read', 'ReadWrite')
try {
    $len = [Math]::Min(400KB, $fs.Length)
    $fs.Seek(-$len, 'End') | Out-Null
    $buf = New-Object byte[] $len
    $fs.Read($buf, 0, $len) | Out-Null
} finally { $fs.Close() }
$coada = [Text.Encoding]::UTF8.GetString($buf)

$m = [regex]::Matches($coada, '"usage":\{.*?"output_tokens":\d+')
if ($m.Count -eq 0) { exit 0 }
$ultim = $m[$m.Count - 1].Value
$total = 0
foreach ($camp in @('input_tokens', 'cache_creation_input_tokens', 'cache_read_input_tokens')) {
    if ($ultim -match ('"' + $camp + '":(\d+)')) { $total += [int]$Matches[1] }
}
$k = [Math]::Round($total / 1000)

$mesaj = ''
if ($total -ge $PragMax) {
    $mesaj = "CONTEXT ${k}k - peste limita de $([Math]::Round($PragMax/1000))k (regula 9): scrie handoff-ul in docs\progres.md si preda sesiunea acum."
} elseif ($total -ge $Prag) {
    $mesaj = "CONTEXT ${k}k - peste $([Math]::Round($Prag/1000))k (regula 9): actualizeaza docs\progres.md si pregateste predarea; deleaga la subagenti ce mai ai de citit/testat."
}
if ($mesaj) {
    if ($Stdout) { Write-Output $mesaj; exit 0 }
    [Console]::Error.WriteLine($mesaj)
    exit 2
}
if ($Intotdeauna) { Write-Output "CONTEXT ${k}k" }
exit 0