# ===== パラメーター =====
# Usage:
# .\msgsendbygrahapi.ps1 -msgsubj "TITLE" -msgbody "BODY" -msgto "toaddr@dummy.test"
# .\msgsendbygrahapi.ps1 "TITLE" "BODY" "toaddr@dummy.test"
# .\msgsendbygrahapi.ps1 "TITLE" "BODY"
param (
  [string]$msgsubj = "[Graph API] メッセージのタイトルです",
  [string]$msgbody = "[Graph API] メッセージの本文です。",
  #既定の宛先メールアドレス
  [string]$msgto = "toaddr@dummy.test"
)

# ===== テナントとメールアドレスの設定 =====
$TenantId   = "XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX"
$ClientId   = "XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX"
$ClientSecret = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
$from = "yourmailbox@dummy.test"
$to   = $msgto
#$cc   = "ccaddr1@dummy.test","ccaddr2@dummy.test"
$cc = ""

# ===== トークン取得 =====
$tokenBody = @{
  grant_type  = "client_credentials"
  scope   = "https://graph.microsoft.com/.default"
  client_id   = $clientId
  client_secret = $clientSecret
}

$tokenResponse = Invoke-RestMethod `
  -Method Post `
  -Uri "https://login.microsoftonline.com/$tenantId/oauth2/v2.0/token" `
  -Body $tokenBody

$accessToken = $tokenResponse.access_token

# ===== メール作成 =====
$message = @{
  subject = $msgsubj
  body = @{
    contentType = "Text"
    content   = $msgbody
  }
  toRecipients = @(
    @{
    emailAddress = @{
      address = $to
    }
    }
  )
  from = @{
  emailAddress = @{
    address = $from
  }
  }
}
if($cc) {
  if($cc.Count -gt 1) {
  $ccRecipients = foreach ($c in $cc) {
    @{
      emailAddress = @{
        address = $c
      }
     }
  }
  } else {
  $ccRecipients = @(
    @{
      emailAddress = @{
        address = $cc
      }
    }
  )
  }
  $message.ccRecipients = $ccRecipients
}

$mailBody = @{
  message = $message
  saveToSentItems = $true
} | ConvertTo-Json -Depth 5

# ===== 文字化け対策 =====
$mailBody = [System.Text.Encoding]::UTF8.GetBytes($mailBody )

# ===== 送信 =====
$uri = "https://graph.microsoft.com/v1.0/users/$from/sendMail"

$headers = @{
  Authorization = "Bearer $accessToken"
  "Content-Type" = "application/json"
}

Invoke-RestMethod -Method Post -Uri $uri -Headers $headers -Body $mailBody 

Write-Host "メール送信完了"