param(
    [Parameter(Mandatory=$true)]
    [ValidateSet("unread_count","latest","send_clipboard","summarize_inbox")]
    [string]$Action,

    [string]$Recipient = "",
    [string]$Body = "",
    [int]$Limit = 5
)

$ErrorActionPreference = 'Stop'
$OutputEncoding = [System.Text.Encoding]::UTF8
[Console]::OutputEncoding = [System.Text.Encoding]::UTF8

# Output protocol (parsed by Lua scripts):
#   First line: "OK" or "ERR:<code>" or "ERR:<code>:<message>"
#   Subsequent lines depend on Action:
#     unread_count    -> "<count>"
#     latest          -> "FROM\t<name>" / "SUBJECT\t<subj>" / "PREVIEW\t<body200>"
#     send_clipboard  -> "TO\t<name>" / "ADDR\t<email>" / "SUBJECT\t<subj>"
#     summarize_inbox -> repeated "FROM\t<name>\tSUBJECT\t<subj>"
#
# All multiline strings get newlines collapsed to spaces before printing.

function Clean-Line([string]$s) {
    if (-not $s) { return "" }
    $s = $s -replace "`r", " " -replace "`n", " " -replace "`t", " "
    return ($s -replace '\s+', ' ').Trim()
}

function Fail($code, $msg = "") {
    if ($msg) {
        Write-Output ("ERR:{0}:{1}" -f $code, (Clean-Line $msg))
    } else {
        Write-Output ("ERR:{0}" -f $code)
    }
    exit 0
}

function Get-OutlookSession {
    try {
        $ol = New-Object -ComObject Outlook.Application
        $ns = $ol.GetNamespace("MAPI")
        return @{ App = $ol; Ns = $ns }
    } catch {
        Fail "outlook_unavailable" $_.Exception.Message
    }
}

function Strip-Html([string]$s) {
    if (-not $s) { return "" }
    $s = [regex]::Replace($s, '<[^>]+>', ' ')
    $s = $s -replace '&nbsp;', ' ' -replace '&amp;', '&' -replace '&lt;', '<' -replace '&gt;', '>' -replace '&quot;', '"' -replace "&#39;", "'"
    return Clean-Line $s
}

function Resolve-Recipient([object]$ns, [string]$query) {
    if ([string]::IsNullOrWhiteSpace($query)) { return $null }
    try {
        $r = $ns.CreateRecipient($query)
        $null = $r.Resolve()
        if ($r.Resolved) {
            $addr = $null
            try { $addr = $r.AddressEntry.GetExchangeUser().PrimarySmtpAddress } catch { }
            if (-not $addr) {
                try { $addr = $r.AddressEntry.Address } catch { }
            }
            if (-not $addr) { $addr = $r.Name }
            return @{ Name = $r.Name; Address = $addr }
        }
    } catch { }
    return $null
}

switch ($Action) {
    "unread_count" {
        $s = Get-OutlookSession
        try {
            $inbox = $s.Ns.GetDefaultFolder(6)
            $count = 0
            try { $count = [int]$inbox.UnReadItemCount } catch { }
            if (-not $count) {
                $count = ($inbox.Items | Where-Object { $_.UnRead -eq $true }).Count
            }
            Write-Output "OK"
            Write-Output ([int]$count).ToString()
        } catch {
            Fail "inbox_failed" $_.Exception.Message
        }
    }

    "latest" {
        $s = Get-OutlookSession
        try {
            $inbox = $s.Ns.GetDefaultFolder(6)
            $items = $inbox.Items
            $items.Sort("[ReceivedTime]", $true)
            $latest = $null
            foreach ($it in $items) {
                if ($it.Class -eq 43) { $latest = $it; break }   # olMail = 43
            }
            if (-not $latest) { Fail "empty_inbox" }
            $fromName = ""
            try { $fromName = $latest.SenderName } catch { }
            if (-not $fromName) { try { $fromName = $latest.SenderEmailAddress } catch { } }
            $subject = ""
            try { $subject = $latest.Subject } catch { }
            $body = ""
            try { $body = $latest.Body } catch { }
            if (-not $body) {
                try { $body = Strip-Html $latest.HTMLBody } catch { }
            } else {
                $body = Clean-Line $body
            }
            if ($body.Length -gt 200) { $body = $body.Substring(0, 200) + "..." }
            Write-Output "OK"
            Write-Output ("FROM`t{0}"    -f (Clean-Line $fromName))
            Write-Output ("SUBJECT`t{0}" -f (Clean-Line $subject))
            Write-Output ("PREVIEW`t{0}" -f $body)
        } catch {
            Fail "latest_failed" $_.Exception.Message
        }
    }

    "send_clipboard" {
        if ([string]::IsNullOrWhiteSpace($Recipient)) { Fail "no_recipient" }
        $s = Get-OutlookSession
        try {
            $resolved = Resolve-Recipient $s.Ns $Recipient
            if (-not $resolved) { Fail "unresolved" $Recipient }
            $bodyText = if ($Body) { $Body } else { "" }
            $subject = ""
            if ($bodyText) {
                $firstLine = ($bodyText -split "`r?`n", 2)[0].Trim()
                if ($firstLine.Length -gt 60) {
                    $subject = $firstLine.Substring(0, 60).Trim()
                } else {
                    $subject = $firstLine
                }
            }
            if ([string]::IsNullOrWhiteSpace($subject)) { $subject = "From J.A.R.V.I.S." }

            $mail = $s.App.CreateItem(0)
            $mail.To = $resolved.Address
            $mail.Subject = $subject
            $mail.Body = $bodyText
            $mail.Send()
            Write-Output "OK"
            Write-Output ("TO`t{0}"      -f (Clean-Line $resolved.Name))
            Write-Output ("ADDR`t{0}"    -f (Clean-Line $resolved.Address))
            Write-Output ("SUBJECT`t{0}" -f (Clean-Line $subject))
        } catch {
            Fail "send_failed" $_.Exception.Message
        }
    }

    "summarize_inbox" {
        $s = Get-OutlookSession
        try {
            $inbox = $s.Ns.GetDefaultFolder(6)
            $items = $inbox.Items
            $items.Sort("[ReceivedTime]", $true)
            $taken = 0
            $lines = @()
            foreach ($it in $items) {
                if ($taken -ge $Limit) { break }
                if ($it.Class -ne 43) { continue }
                $unread = $false
                try { $unread = [bool]$it.UnRead } catch { }
                if (-not $unread) { continue }
                $fromName = ""
                try { $fromName = $it.SenderName } catch { }
                $subj = ""
                try { $subj = $it.Subject } catch { }
                $lines += ("FROM`t{0}`tSUBJECT`t{1}" -f (Clean-Line $fromName), (Clean-Line $subj))
                $taken += 1
            }
            Write-Output "OK"
            foreach ($l in $lines) { Write-Output $l }
        } catch {
            Fail "summary_failed" $_.Exception.Message
        }
    }
}