param(
    [switch]$debug,
    [switch]$clear,
    [switch]$noplan
)

if ($debug) {
    $script:debug = $debug
}

if($noplan) {
    $script:noplan = $noplan
}

$teamsName = "IT Support & Delivery" 
$scheduleGroupName = "IT SUPPORT"
$ClientId = "6cb76bbf-f253-4551-87a8-5e1f49d8ace3"
$ClientSecret = "IQg8Q~JTBTDbrHyjKMc.KMSETtQoKWvUhnCr1aY1" 
$tenantid = "e81b4a31-e8ad-4df6-aa30-3bdcc1da2cdd" 
$userIdAdmin = "747bd624-5cd7-4ae0-952f-5dc374e07a5e"
$logPath = (".\log_{0}.log" -f (Get-Date).toString("yyyy_MM_dd"))

function Write-Debug {
    param(
        [string]$message
    )
    if ($script:debug) {
        Write-Host $message
    }
    else {
        $message | Add-Content $logPath
    }
}

function Set-Shift {
    param(
        [string]$userId,
        [string]$groupID,
        [string]$shiftName,
        [System.DateTime]$StartDate,
        [System.DateTime]$EndDate,
        [string]$color,
        [string]$teamID,
        [string]$mail
    )

    $params = @{
            UserId            = $userId
            schedulingGroupId = $groupID
            sharedShift       = @{
            notes         = ($shiftName)
            startDateTime = [System.DateTime]::Parse($StartDate.ToString("yyyy-MM-dd'T'HH:mm:ssZ"))
            endDateTime   = [System.DateTime]::Parse($EndDate.ToString("yyyy-MM-dd'T'HH:mm:ssZ"))
            theme         = $color
       }
    }

    if($script:noplan -eq $false) {
        $newShift = New-MgTeamScheduleShift -TeamId $teamID -BodyParameter $params -Headers @{ "MS-APP-ACTS-AS" = $userIdAdmin }
        Write-Debug("{0} {1}: setting {2}'s shift - {3} {4}-{5}" -f $dayDate, $dayDate.DayOfWeek, $mail, $shiftName, $StartDate, $EndDate)
    }
    else {
        Write-Debug("{0} {1}: Not setting {2}'s shift - {3} {4}-{5} - running with -noplan" -f $dayDate, $dayDate.DayOfWeek, $mail, $shiftName, $StartDate, $EndDate)
        $newshift = 0
    }
    

    return $newShift
}

function Remove-Shift {
    param(
        [PSCustomObject]$shift,
        [string]$teamID
    )

    if($script:noplan -eq $false) {
        Write-Debug("{0} {1}: removing {2}'s shift - {2} {3}-{4}" -f $dayDate, $dayDate.DayOfWeek, $futureds_email, $shift.Notes, $shift.StartDateTime, $shift.EndDateTime)
        Remove-MgTeamScheduleShift -ShiftId $shift.id -TeamId $teamID
    }
    else {
        Write-Debug("{0} {1}: Not removing {2}'s shift - {2} {3}-{4} - running with -noplan" -f $dayDate, $dayDate.DayOfWeek, $futureds_email, $shift.Notes, $shift.StartDateTime, $shift.EndDateTime)
    }
}

function Invoke-HasTimeOff {
    param(
        [string]$UID,
        [PSCustomObject]$timeoff,
        [string]$mail
    )

    foreach ($toff in $timeoff) {
        if($toff.UserId -eq $UID) {
            Write-Debug("{0} {1}: {2} has time off" -f $dayDate, $dayDate.DayOfWeek, $mail)
            return $true
            break
        }
    }
    return $false
}
function Invoke-HasShift {
    param(
        [string]$UID,
        [PSCustomObject]$shifts,
        [string]$mail
    )

    foreach ($shift in $shifts) {
        if($shift.UserId -eq $UID) {
            Write-Debug("{0} {1}: {2} has a shift already - {3} {4}-{5}" -f $dayDate, $dayDate.DayOfWeek, $mail, $shift.SharedShift.Notes, $shift.SharedShift.StartDateTime, $shift.SharedShift.EndDateTime)
            return $true
            break
        }
    }
    return $false
}

function Invoke-HasShiftorTimeOff {
    param(
        [string]$UID,
        [PSCustomObject]$shifts,
        [PSCustomObject]$timeoff,
        [string]$mail
    )

    foreach ($shift in $shifts) {
        if($shift.UserId -eq $UID) {
            Write-Debug("{0} {1}: {2} has a shift already - {3} {4}-{5}" -f $dayDate, $dayDate.DayOfWeek, $mail, $shift.SharedShift.Notes, $shift.SharedShift.StartDateTime, $shift.SharedShift.EndDateTime)
            return $true
            break
        }
    }

    foreach ($toff in $timeoff) {
        if($toff.UserId -eq $UID) {
            Write-Debug("{0} {1}: {2} has time off" -f $dayDate, $dayDate.DayOfWeek, $mail)
            return $true
            break
        }
    }
    return $false
}

$body = @{
    grant_type    = "client_credentials"
    resource      = "https://graph.microsoft.com"
    client_id     = $ClientId
    client_secret = $ClientSecret
}
$authUri = "https://login.microsoftonline.com/$tenantid/oauth2/token"
$response = Invoke-RestMethod $authUri -Method 'POST' -Body $body

$token = $response.access_token

Import-Module Microsoft.Graph.Teams
Connect-MgGraph -AccessToken $($token | ConvertTo-SecureString -AsPlainText -Force) >> $null

# ---| SCHEDULE |---
$schedule = Get-Content -Path "./config.json" -Raw | ConvertFrom-Json

# ---| ALL MEMBERS SPECIFIED IN THE SCHEDULE |---
$allemails = $schedule.PSObject.Properties | ForEach-Object {
    if ($_.Name -in @("monday", "tuesday", "wednesday", "thursday", "friday")) {
        $_.Value.PSObject.Properties | ForEach-Object {
            if ($_.Name -in @("ds", "ho", "os", "ns")) {
                $_.Value | ForEach-Object {
                    $_
                }
            }
        }
    }
} | Select-Object -Unique

# --------------------------- | DATE SETTINGS | ---------------------------

# ---| Today's date |---
$today = (Get-Date).Date

# ---| Specific date |---
#$today = Get-Date -Day 27 -Month 10 -Year 2025 -Hour 9 -Minute 00 -Second 00 -Millisecond 00

$daysahead = 14 #How many days ahead to plan
$timeoff_past_look = -7 #How many days to look into the past for the start of a multi-day time off

# ---| Time span |---
$startSpanDate = Get-Date -Day $today.Day -Month $today.Month -Year $today.Year -Hour 9 -Minute 00 -Second 00 -Millisecond 00
$endSpanDate = Get-Date -Day $startSpanDate.AddDays($daysahead).Day -Month $startSpanDate.AddDays($daysahead).Month -Year $startSpanDate.AddDays($daysahead).Year -Hour 17 -Minute 00 -Second 00 -Millisecond 00

# --------------------------- | RLCZ MAINTENANCE SETTINGS | ---------------------------

$rlcz_mtnc_email = "jiri.kotlan@itego.cz"
$rlcz_shift_reduction = -3 #How many hours does the next day shift get reduced by

# --------------------------- | MAIN SCRIPT | ---------------------------

try {
    $team = Get-MgTeam -Property "id,displayName" | Where-Object -property displayName -value $teamsName -eq
    $group = Get-MgTeamScheduleSchedulingGroup -TeamId  $team.id -Headers @{ "MS-APP-ACTS-AS" = $userIdAdmin } |  Where-Object -property displayName -value $scheduleGroupName -eq
    
    $allshifts = [object[]] (Get-MgTeamScheduleShift -TeamId $team.id -Filter "SharedShift/StartDateTime ge $($startSpanDate.toString('yyyy-MM-ddT00:00:00Z'))" -All  -Headers @{ "MS-APP-ACTS-AS" = $userIdAdmin })
    $timeoff_all = [object[]] (Get-MgTeamScheduleTimeOff -TeamId $team.id -Filter "SharedTimeOff/StartDateTime ge $($startSpanDate.AddDays($timeoff_past_look).toString('yyyy-MM-ddT00:00:00Z'))" -All  -Headers @{ "MS-APP-ACTS-AS" = $userIdAdmin } | Select-Object -Property *,@{name="Date";expression={$_.SharedTimeOff.StartDateTime.AddHours(1).Date}})

    # ---| SHIFT CLEARING with -clear |---
    if ($clear) {
        foreach ($shift in $allshifts) {
            if($shift.SharedShift.Notes -ne "RLCZ") {
                Remove-Shift -shift $shift -teamID $team.Id
            }
        }
       return
    }

    
    $timeSpan = New-TimeSpan -Start $startSpanDate -End $endSpanDate
    Write-Debug("Planning from {0} to {1}" -f $startSpanDate, $endSpanDate)

    # ---| DAY LOOP |---
    for ($dayNumber = 0; $dayNumber -lt $timespan.Days; $dayNumber++) {
        $dayDate = $today.AddDays($dayNumber);

        # ---| WEEKEND CHECK |---
        if($dayDate.DayOfWeek -in  @("Saturday", "Sunday")) {
            Write-Debug("{0} {1}: skipping weekend day" -f $dayDate, $dayDate.DayOfWeek)
            continue
        }

        # ---| NEW DAY INIT |---
        $ds_shift_inplace = $false
        $ho_emails = $schedule.($dayDate.DayOfWeek.ToString().ToLower()).'ho'
        $ds_email = $schedule.($dayDate.DayOfWeek.ToString().ToLower()).'ds'
        $os_emails = $schedule.($dayDate.DayOfWeek.ToString().ToLower()).'os'
        $ns_emails = $schedule.($dayDate.DayOfWeek.ToString().ToLower()).'ns'

        # ---| TIME SYNC |---
        $dateStart = $(get-date -Day $dayDate.Day -Month $dayDate.Month -Year $dayDate.Year -Hour 9 -Minute 00 -Second 00).AddHours(-1)
        $dateEnd = $(get-date -Day $dayDate.Day -Month $dayDate.Month -Year $dayDate.Year -Hour 17 -Minute 00 -Second 00).AddHours(-1)
           
        if (($dayDate.IsDaylightSavingTime()) -eq $true) {
            $dateStart = $dateStart.AddHours(-1)
            $dateEnd = $dateEnd.AddHours(-1)
        }

        $dayEnd = Get-Date -Day $dayDate.Day -Month $dayDate.Month -Year $dayDate.Year -Hour 23 -Minute 00 -Second 0
        $dayStart = $dayEnd.AddDays(-1)

        # ---| TODAY'S SHIFTS AND TIME OFF |---
        $shifts_today = [Object[]] $allshifts | Where-Object -Filter { 
            $_.schedulingGroupId -eq $group.Id -and $_.SharedShift.StartDateTime.ToString("yyyy-MM-dd HH:mm") -ge $dateStart.ToString("yyyy-MM-dd HH:mm") -and $_.SharedShift.EndDateTime.ToString("yyyy-MM-dd HH:mm") -le $dateEnd.ToString("yyyy-MM-dd HH:mm") 
        }

        $timeoff_today = [Object[]] $timeoff_all | Where-Object {
            $_.SharedTimeOff.StartDateTime.Date -le $dayStart.Date -and
            $_.SharedTimeOff.EndDateTime.Date -ge $dayEnd.Date
        }
            
        $manual_dayshifts = [Object[]] $shifts_today | Where-Object -Filter { ($_.SharedShift.Notes -eq "Home Office - Denní směna") -or ($_.SharedShift.Notes -eq "Office - Denní směna") }
            
        if ($null -eq $manual_dayshifts) {
            $ds_shift_inplace = $false
            Write-Debug("{0} {1}: day shift not yet set" -f $dayDate, $dayDate.DayOfWeek)
        }
        else {
            $ds_shift_inplace = $true
            Write-Debug("{0} {1}: day shift set already" -f $dayDate, $dayDate.DayOfWeek)
        }

        # ---| TEAM MEMBER LOOP |---
        foreach($email in $allemails) {
            $userId = $(Get-MgUser -Filter "UserPrincipalName eq '$email' or proxyAddresses/any(c:c eq 'smtp:$email')").Id

            # ---| DAY SHIFT CHECK |---
            if($ds_shift_inplace -eq $false) {
                if($email -eq $ds_email) {
                    Write-Debug("{0} {1}: checking {2} for day shift availability..." -f $dayDate, $dayDate.DayOfWeek, $email)

                    # ---| IF DAY SHIFT CAN BE ASSIGNED TO THE PROPER MEMEBER |---
                    if((Invoke-HasShiftorTimeOff -UID $userId -shifts $shifts_today -timeoff $timeoff_today -mail $email) -eq $false) {
                        # ---| HOME-OFFICE DAY SHIFT |---
                        if ($email -in $ho_emails) {
                            $newshift = Set-Shift -userId $userId -groupID $group.id -shiftName "Home Office - Denní směna" -StartDate $dateStart -EndDate $dateEnd -color "purple" -teamID $team.id -mail $email
                            $allshifts += [Object[]] $newshift
                            $ds_shift_inplace = $true
                            continue
                        }
                        # ---| OFFICE DAY SHIFT |---
                        else {
                            $newshift = Set-Shift -userId $userId -groupID $group.id -shiftName "Office - Denní směna" -StartDate $dateStart -EndDate $dateEnd -color "purple" -teamID $team.id -mail $email
                            $allshifts += [Object[]] $newShift
                            $ds_shift_inplace = $true
                            continue
                        }
                    }

                    # ---| DAY SHIFT REPLACEMENT CHECK |---
                    else { 
                        Write-Debug("{0} {1}: looking ahead for a day shift replacement" -f $dayDate, $dayDate.DayOfWeek)
                        $remainingdays = $timespan.Days - $dayNumber
                        
                        # ---| FUTURE DAYS LOOP |---
                        for ($daysahead = 1; $daysahead -lt $remainingdays; $daysahead++) {
                            $futureday = $dayDate.AddDays($daysahead)

                            # ---| WEEKEND CHECK |---
                            if ($futureday.DayOfWeek -in @("Saturday", "Sunday")) {
                                Write-Debug(">>> {0} {1}: skipping weekend day" -f $futureday, $futureday.DayOfWeek, $futureds_email)
                                continue
                            }

                            # ---| NEXT IN LINE FOR THE DAY-SHIFT |---
                            $futureds_email = $schedule.($futureday.DayOfWeek.ToString().ToLower()).'ds'
                            $futureds_id = $(Get-MgUser -Filter "UserPrincipalName eq '$futureds_email' or proxyAddresses/any(c:c eq 'smtp:$futureds_email')").Id
                            Write-Debug(">>> {0} {1}: {2} has it on that day" -f $futureday, $futureday.DayOfWeek, $futureds_email)

                            # ---| THE NEXT IN LINE FOR THE DAY-SHIFT DOESN'T HAVE TIME OFF, NO-SHIFT OR ON-SITE |---
                            if((Invoke-HasTimeOff -UID $futureds_id -timeoff $timeoff_today -mail $futureds_email) -eq $false -and ($futureds_email -notin $os_emails) -and ($futureds_email -notin $ns_emails)) {
                                
                                # ---| NEXT IN LINE DOESN'T HAVE A SHIFT ALREADY |---
                                if((Invoke-HasShift -UID $futureds_id -shifts $shifts_today -mail $futureds_email) -eq $false) {

                                    # ---| HOME-OFFICE DAY SHIFT |---
                                    if($futureds_email -in $ho_emails) {
                                        $newshift = Set-Shift -userId $futureds_id -groupID $group.id -shiftName "Home Office - Denní směna" -StartDate $dateStart -EndDate $dateEnd -color "purple" -teamID $team.id -mail $futureds_email
                                        $allshifts += [Object[]] $newshift
                                        $ds_shift_inplace = $true
                                        break
                                    }
                                    # ---| OFFICE DAY SHIFT |---
                                    else {
                                        $newshift = Set-Shift -userId $futureds_id -groupID $group.id -shiftName "Office - Denní směna" -StartDate $dateStart -EndDate $dateEnd -color "purple" -teamID $team.id -mail $futureds_email
                                        $allshifts += [Object[]] $newShift
                                        $ds_shift_inplace = $true
                                        break
                                    }
                                }
                                # ---| NEXT IN LINE HAS A SHIFT ALREADY |---
                                else {
                                    # ---| LOOKING FOR THE SHIFT |---
                                    foreach ($shift in $shifts_today) {
                                        if($shift.UserId -eq $futureds_id) {
                                            # ---| REMOVE THE SHIFT |---
                                            Remove-Shift -shift $shift -teamID $team.Id
                                            
                                            # ---| HOME-OFFICE DAY SHIFT |---
                                            if($futureds_email -in $ho_emails) {
                                                $newshift = Set-Shift -userId $futureds_id -groupID $group.id -shiftName "Home Office - Denní směna" -StartDate $dateStart -EndDate $dateEnd -color "purple" -teamID $team.id -mail $futureds_email
                                                $allshifts += [Object[]] $newshift
                                                $ds_shift_inplace = $true
                                                break
                                            }
                                            # ---| OFFICE DAY SHIFT |---
                                            else {
                                                $newshift = Set-Shift -userId $futureds_id -groupID $group.id -shiftName "Office - Denní směna" -StartDate $dateStart -EndDate $dateEnd -color "purple" -teamID $team.id -mail $futureds_email
                                                $allshifts += [Object[]] $newShift
                                                $ds_shift_inplace = $true
                                                break
                                            }
                                        }
                                    }
                                }

                            }
                            # ---| IF THE DAY SHIFT IS SET, BREAK OUT OF THE FUTURE DAYS LOOP |---
                            if($ds_shift_inplace -eq $true) {
                                break
                            }
                            # ---| MOVE ON TO THE NEXT FUTURE DAY IF NO CONDITION IS MET |---
                            continue
                        }
                    }
                }
            }
            # ---| END OF THE DAY SHIFT CHECK SECTION |---
                
            # ---| UPDATE COLLECTION OF SHIFTS TODAY |---
            $shifts_today = [Object[]] $allshifts | Where-Object -Filter { 
                $_.schedulingGroupId -eq $group.Id -and $_.SharedShift.StartDateTime.ToString("yyyy-MM-dd HH:mm") -ge $dateStart.ToString("yyyy-MM-dd HH:mm") -and $_.SharedShift.EndDateTime.ToString("yyyy-MM-dd HH:mm") -le $dateEnd.ToString("yyyy-MM-dd HH:mm") 
            }

            # ---| ON-SITE SHIFT CHECK |---
            if($email -in $os_emails) {
                if((Invoke-HasShiftorTimeOff -UID $userId -shifts $shifts_today -timeoff $timeoff_today -mail $email) -eq $false) {
                    $newshift = Set-Shift -userId $userId -groupID $group.id -shiftName "On-site" -StartDate $dateStart -EndDate $dateEnd -color "gray" -teamID $team.id -mail $email
                    $allshifts += [Object[]] $newshift
                    continue
                }
            }

            # ---| NO-SHIFT CHECK |---
            if($email -in $ns_emails) {
                Write-Debug("{0} {1}: {2} has no-shift defined for today" -f $dayDate, $dayDate.DayOfWeek, $email)
                continue
            }

            # ---| RLCZ MAINTENANCE CHECK |---
            if($email -eq $rlcz_mtnc_email) {
                if ($dayDate.DayOfWeek -eq "Thursday") {
                    $yesterday = $dayDate.AddDays(-1)
                    $rlcz_shifts = [Object[]] $allshifts | Where-Object -Filter { $_.schedulingGroupId -eq $group.Id -and $_.SharedShift.Notes -eq "RLCZ" -and ($_.SharedShift.StartDateTime.Date -eq $yesterday.Date -or $_.SharedShift.EndDateTime.Date -eq $yesterday.Date) }
                        
                    if (Invoke-HasShift -UID $userId -shifts $rlcz_shifts -mail $email) {
                        if((Invoke-HasShiftorTimeOff -UID $userId -shifts $shifts_today -timeoff $timeoff_today -mail $email) -eq $false) {
                            if($email -in $ho_emails) {
                                $newshift = Set-Shift -userId $userId -groupID $group.id -shiftName "Home office" -StartDate $dateStart -EndDate $dateEnd.AddHours($rlcz_shift_reduction) -color "pink" -teamID $team.id -mail $email
                                $allshifts += [Object[]] $newshift
                                continue
                            }
                            else {
                                $newshift = Set-Shift -userId $userId -groupID $group.id -shiftName "Office" -StartDate $dateStart -EndDate $dateEnd.AddHours($rlcz_shift_reduction) -color "blue" -teamID $team.id -mail $email
                                $allshifts += [Object[]] $newshift
                                continue
                            }
                        }
                    }
                }
            }

            # ---| HOME-OFFICE CHECK |---
            if($email -in $ho_emails) {
                if((Invoke-HasShiftorTimeOff -UID $userId -shifts $shifts_today -timeoff $timeoff_today -mail $email) -eq $false) {
                    $newshift = Set-Shift -userId $userId -groupID $group.id -shiftName "Home office" -StartDate $dateStart -EndDate $dateEnd -color "pink" -teamID $team.id -mail $email
                    $allshifts += [Object[]] $newshift
                    continue
                }
            }

            # ---| OFFICE DEFAULT |---
            if((Invoke-HasShiftorTimeOff -UID $userId -shifts $shifts_today -timeoff $timeoff_today -mail $email) -eq $false) {
                $newshift = Set-Shift -userId $userId -groupID $group.id -shiftName "Office" -StartDate $dateStart -EndDate $dateEnd -color "blue" -teamID $team.id -mail $email
                $allshifts += [Object[]] $newshift
                continue
            }
        }
    }

    # ---| SCHEDULE SHARING |---
    if($script:noplan -eq $false) {

        $params = @{
            notifyTeam    = $false
            startDateTime = [System.DateTime]::Parse($startSpanDate.ToString("yyyy-MM-dd'T'HH:mm:ssZ"))
            endDateTime   = [System.DateTime]::Parse($endSpanDate.ToString("yyyy-MM-dd'T'HH:mm:ssZ"))
        }

        Invoke-MgShareTeamSchedule -TeamId $team.Id -BodyParameter $params -Headers @{ "MS-APP-ACTS-AS" = $userIdAdmin }
        ("SHARING: {0}" -f $scheduleGroupName) | Add-Content -Path $logPath
    
    }
    else {
        Write-Debug("Schedule not shared because of -noplan")
    }
}
catch {
    $_
    break;
}