# Mohe & XiaoXiaoMo Chat Viewer
# Lists [mohe]/[xxm] messages from an OpenCode session.
#
# Usage:
#   .\moho_chat.ps1 <session_id> [minutes]
#
# Examples:
#   .\moho_chat.ps1 ses_1d95d15c4ffehQaZ6hrbIbak5k
#   .\moho_chat.ps1 ses_1d95d15c4ffehQaZ6hrbIbak5k 30

param(
    [Parameter(Mandatory=$true)][string]$SessionId,
    [int]$Minutes = 0
)

$ErrorActionPreference = 'Stop'

Write-Host "Exporting session..." -ForegroundColor DarkGray

$tmpFile = [System.IO.Path]::GetTempFileName() + ".json"
$env:CI = 'true'
opencode.cmd export $SessionId 2>$null | Set-Content -Path $tmpFile -NoNewline -Encoding UTF8

if (-not (Test-Path $tmpFile) -or (Get-Item $tmpFile).Length -eq 0) {
    Write-Error "Export failed"
    exit 1
}

$size = (Get-Item $tmpFile).Length
Write-Host "Read ($($size / 1MB -as [int]) MB)" -ForegroundColor DarkGray

$raw = Get-Content $tmpFile -Raw -Encoding UTF8
Remove-Item $tmpFile -Force

# Check if it's actually UTF-16LE in disguise (opencode export uses UTF-16LE)
if ($raw.Length -eq 0 -or $raw[0] -ne '{') {
    # Re-read as UTF-16
    $bytes = [System.IO.File]::ReadAllBytes($tmpFile)
    Remove-Item $tmpFile -Force
    $raw = [System.Text.Encoding]::Unicode.GetString($bytes)
}

$brace = $raw.IndexOf('{')
if ($brace -gt 0) { $raw = $raw.Substring($brace) }

# Use regex to find "text": "[mohe]..." patterns directly (no JSON parsing)
$pattern = '"text":\s*"\[(mohe|xxm)\][^"]*"'

$cutoff = if ($Minutes -gt 0) { (Get-Date).ToUniversalTime().AddMinutes(-$Minutes) } else { $null }

$results = @()
$matchPos = 0

while ($true) {
    $m = [regex]::Match($raw, $pattern, $matchPos)
    if (-not $m.Success) { break }
    $matchPos = $m.Index + 1
    
    $tag = $m.Groups[1].Value
    $content = $m.Value
    
    # Extract the full text content (everything between "text": " and the closing ")
    $start = $m.Index + $m.Value.IndexOf('"', $m.Value.IndexOf(':')+1) + 1
    $fullText = ''
    $escape = $false
    for ($i = $start; $i -lt $raw.Length; $i++) {
        $c = $raw[$i]
        if ($escape) { $fullText += $c; $escape = $false }
        elseif ($c -eq '\') { $fullText += $c; $escape = $true }
        elseif ($c -eq '"') { break }
        else { $fullText += $c }
    }
    
    $fullText = $fullText.Trim()
    if (-not ($fullText.StartsWith('[mohe]') -or $fullText.StartsWith('[xxm]'))) { continue }
    
    $sender = if ($fullText.StartsWith('[mohe]')) { '[mohe] Mohe' } else { '[xxm] XiaoXiaoMo' }
    $display = $fullText -replace '^\[\w+\]\s*', ''
    
    # Get timestamp by looking backward
    $before = $raw.Substring([Math]::Max(0, $m.Index - 3000), [Math]::Min(3000, $m.Index))
    $tsMatch = [regex]::Match($before, '"timestamp":\s*"([^"]+)"')
    $tsStr = if ($tsMatch.Success) { $tsMatch.Groups[1].Value } else { '' }
    
    if (-not $tsStr) {
        $crMatch = [regex]::Match($before, '"created":\s*(\d+)')
        if ($crMatch.Success) {
            $tsStr = ([DateTimeOffset]::FromUnixTimeMilliseconds([long]$crMatch.Groups[1].Value).UtcDateTime).ToString('o')
        }
    }
    
    $ts = $null
    if ($tsStr) {
        try { $ts = [DateTime]::Parse($tsStr, $null, [System.Globalization.DateTimeStyles]::AssumeUniversal) } catch {}
    }
    
    if ($cutoff -and $ts -and $ts -lt $cutoff) { continue }
    
    $timeLocal = if ($ts) { $ts.ToLocalTime().ToString('HH:mm:ss') } else { '??' }
    
    $results += [PSCustomObject]@{ Time=$timeLocal; Sort=if($ts){$ts.Ticks}else{0}; Sender=$sender; Message=$display }
}

$results = $results | Sort-Object Sort

if ($results.Count -eq 0) {
    Write-Host "No [mohe]/[xxm] messages found" -ForegroundColor Yellow
    if ($Minutes -gt 0) { Write-Host "(last $Minutes minutes)" }
    exit
}

Write-Host "`n$($results.Count) message(s)" -ForegroundColor Cyan
if ($Minutes -gt 0) { Write-Host "(last $Minutes min)" }
Write-Host ("=" * 60)

foreach ($r in $results) {
    Write-Host ("[{0}] {1}: {2}" -f $r.Time, $r.Sender, $r.Message)
}