param(
    [string]$SourceDump = (Join-Path $PSScriptRoot '..\db\dump-pg-202604211927.pretrim-backup.sql'),
    [string]$OutputDump = (Join-Path $PSScriptRoot '..\db\dump-pg-202604211927.trimmed.sql'),
    [string]$ContainerName = 'regalami-dump-trim-mysql-temp',
    [string]$VolumeName = 'regalami-dump-trim-mysql-temp-data',
    [string]$DatabaseName = 'pgtrim',
    [string]$RootPassword = 'root'
)

$ErrorActionPreference = 'Stop'

function Invoke-DockerCapture {
    param(
        [Parameter(Mandatory = $true)]
        [string[]]$DockerArgs
    )

    $output = & docker @DockerArgs 2>&1
    if ($LASTEXITCODE -ne 0) {
        throw (("docker " + ($DockerArgs -join ' ')) + " failed:`n" + ($output -join "`n"))
    }

    return $output
}

function Invoke-DockerQuiet {
    param(
        [Parameter(Mandatory = $true)]
        [string[]]$DockerArgs
    )

    & docker @DockerArgs | Out-Null
    if ($LASTEXITCODE -ne 0) {
        throw "docker $($DockerArgs -join ' ') failed"
    }
}

function Wait-ForMysqlReady {
    param(
        [Parameter(Mandatory = $true)]
        [string]$Name,
        [Parameter(Mandatory = $true)]
        [string]$Password
    )

    for ($attempt = 0; $attempt -lt 180; $attempt++) {
        $portOutput = & docker exec $Name mysql -N -B -uroot -p$Password -e "SELECT @@port;" 2>$null
        if ($LASTEXITCODE -eq 0) {
            $reportedPort = ($portOutput | Select-Object -First 1).Trim()
            if ($reportedPort -eq '3306') {
                return
            }
        }

        Start-Sleep -Seconds 2
    }

    throw "MySQL in container $Name did not become ready in time."
}

function Invoke-MysqlQuery {
    param(
        [Parameter(Mandatory = $true)]
        [string]$Query,
        [switch]$SkipDatabase
    )

    $dockerArgs = @('exec', $ContainerName, 'mysql', '-N', '-B', '-uroot', "-p$RootPassword")
    if (-not $SkipDatabase) {
        $dockerArgs += @('-D', $DatabaseName)
    }
    $dockerArgs += @('-e', $Query)
    return Invoke-DockerCapture -DockerArgs $dockerArgs
}

function Get-SqlScalar {
    param(
        [Parameter(Mandatory = $true)]
        [string]$Query,
        [switch]$SkipDatabase
    )

    $result = Invoke-MysqlQuery -Query $Query -SkipDatabase:$SkipDatabase
    if (-not $result) {
        return ''
    }

    return ($result | Select-Object -First 1).Trim()
}

function Quote-Identifier {
    param([string]$Name)
    return '`' + $Name.Replace('`', '``') + '`'
}

function Quote-SqlLiteral {
    param([string]$Value)
    return "'" + $Value.Replace("'", "''") + "'"
}

if (-not (Test-Path $SourceDump)) {
    throw "Source dump not found: $SourceDump"
}

$dbDirectory = Split-Path -Parent (Resolve-Path $SourceDump).Path
$sourceFileName = Split-Path -Leaf $SourceDump
$outputFileName = Split-Path -Leaf $OutputDump
$importErrorLogFileName = [System.IO.Path]::GetFileNameWithoutExtension($sourceFileName) + '.import-errors.log'
$importErrorLogPath = Join-Path $dbDirectory $importErrorLogFileName
$sourceSizeBytes = (Get-Item $SourceDump).Length

Write-Host "Using source dump: $SourceDump"
Write-Host "Source size: $sourceSizeBytes bytes"
Write-Host "Import error log: $importErrorLogPath"

try {
    & docker rm -f $ContainerName 1>$null 2>$null
    & docker volume rm $VolumeName 1>$null 2>$null

    Invoke-DockerCapture -DockerArgs @(
        'run', '-d', '--name', $ContainerName,
        '-e', "MYSQL_ROOT_PASSWORD=$RootPassword",
        '-v', "${dbDirectory}:/workspace/db",
        '-v', "${VolumeName}:/var/lib/mysql",
        'mysql:8.4',
        '--max_allowed_packet=1G',
        '--net_read_timeout=600',
        '--net_write_timeout=600'
    ) | Out-Null

    Wait-ForMysqlReady -Name $ContainerName -Password $RootPassword

    Invoke-MysqlQuery -SkipDatabase -Query "DROP DATABASE IF EXISTS $DatabaseName; CREATE DATABASE $DatabaseName CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci;" | Out-Null

    Write-Host "Importing source dump into temporary MySQL database..."
    if (Test-Path $importErrorLogPath) {
        Remove-Item $importErrorLogPath -Force
    }
    Invoke-DockerQuiet -DockerArgs @(
        'exec', $ContainerName, 'sh', '-lc',
        "mysql --force -uroot -p$RootPassword $DatabaseName < /workspace/db/$sourceFileName 2> /workspace/db/$importErrorLogFileName"
    )

    $beforeFoto = [int64](Get-SqlScalar -Query 'SELECT COUNT(*) FROM foto;')
    $beforeLogFoto = [int64](Get-SqlScalar -Query 'SELECT COUNT(*) FROM log_foto;')
    $usersExists = (Get-SqlScalar -SkipDatabase -Query "SELECT COUNT(*) FROM information_schema.tables WHERE table_schema = '$DatabaseName' AND table_name = 'users';") -eq '1'
    $beforeUsers = 0
    if ($usersExists) {
        $beforeUsers = [int64](Get-SqlScalar -Query 'SELECT COUNT(*) FROM users;')
    }

    $garaDateColumn = Get-SqlScalar -SkipDatabase -Query @"
SELECT COLUMN_NAME
FROM information_schema.columns
WHERE table_schema = '$DatabaseName'
  AND table_name = 'gara'
  AND COLUMN_NAME IN ('dataGaraInizio', 'dataGaraFine', 'data', 'createTmst', 'lastUpdTmst')
ORDER BY FIELD(COLUMN_NAME, 'dataGaraInizio', 'dataGaraFine', 'data', 'createTmst', 'lastUpdTmst')
LIMIT 1;
"@
    if (-not $garaDateColumn) {
        throw 'Could not determine race date column from gara table.'
    }

    $usersDateColumn = ''
    if ($usersExists) {
        $usersDateColumn = Get-SqlScalar -SkipDatabase -Query @"
SELECT COLUMN_NAME
FROM information_schema.columns
WHERE table_schema = '$DatabaseName'
  AND table_name = 'users'
  AND COLUMN_NAME IN ('dataInserimento', 'dataInizioVld', 'lastUpdTmst')
ORDER BY FIELD(COLUMN_NAME, 'dataInserimento', 'dataInizioVld', 'lastUpdTmst')
LIMIT 1;
"@
        if (-not $usersDateColumn) {
            $usersDateColumn = 'id_users'
        }
    }

    $garaDateExpr = Quote-Identifier $garaDateColumn
    $usersDateExpr = Quote-Identifier $usersDateColumn

    Invoke-MysqlQuery -Query @"
DROP TABLE IF EXISTS keep_gara_ids;
CREATE TABLE keep_gara_ids AS
SELECT id_gara
FROM gara
ORDER BY $garaDateExpr DESC, id_gara DESC
LIMIT 10;

DROP TABLE IF EXISTS keep_foto_ids;
CREATE TABLE keep_foto_ids AS
SELECT id_foto
FROM foto
WHERE id_gara IN (SELECT id_gara FROM keep_gara_ids);
"@ | Out-Null

    $cleanupStats = [System.Collections.Generic.List[string]]::new()

    Invoke-MysqlQuery -Query 'DELETE FROM log_foto;' | Out-Null
    $cleanupStats.Add('log_foto:deleted-all')

    $fotoDependentTables = Invoke-MysqlQuery -SkipDatabase -Query @"
SELECT table_name
FROM information_schema.columns
WHERE table_schema = '$DatabaseName'
  AND column_name = 'id_foto'
  AND table_name NOT IN ('foto', 'log_foto', 'keep_foto_ids', 'keep_gara_ids')
ORDER BY table_name;
"@

    foreach ($tableName in $fotoDependentTables) {
        if (-not $tableName) {
            continue
        }
        $trimmedTableName = $tableName.Trim()
        $quotedTable = Quote-Identifier $trimmedTableName
        $deletedRows = [int64](Get-SqlScalar -Query "SELECT COUNT(*) FROM $quotedTable WHERE id_foto IS NOT NULL AND id_foto NOT IN (SELECT id_foto FROM keep_foto_ids);")
        if ($deletedRows -gt 0) {
            Invoke-MysqlQuery -Query "DELETE FROM $quotedTable WHERE id_foto IS NOT NULL AND id_foto NOT IN (SELECT id_foto FROM keep_foto_ids);" | Out-Null
            $cleanupStats.Add("$($trimmedTableName):$deletedRows")
        }
    }

    $deletedFotoRows = [int64](Get-SqlScalar -Query 'SELECT COUNT(*) FROM foto WHERE id_foto NOT IN (SELECT id_foto FROM keep_foto_ids);')
    if ($deletedFotoRows -gt 0) {
        Invoke-MysqlQuery -Query 'DELETE FROM foto WHERE id_foto NOT IN (SELECT id_foto FROM keep_foto_ids);' | Out-Null
        $cleanupStats.Add("foto:$deletedFotoRows")
    }

    if ($usersExists) {
        Invoke-MysqlQuery -Query @"
DROP TABLE IF EXISTS keep_user_ids;
CREATE TABLE keep_user_ids AS
SELECT id_users
FROM users
ORDER BY $usersDateExpr ASC, id_users ASC
LIMIT 5;
"@ | Out-Null

        $usersDependentTables = Invoke-MysqlQuery -SkipDatabase -Query @"
SELECT table_name
FROM information_schema.columns
WHERE table_schema = '$DatabaseName'
  AND column_name = 'id_users'
  AND table_name NOT IN ('users', 'keep_user_ids')
ORDER BY table_name;
"@

        foreach ($tableName in $usersDependentTables) {
            if (-not $tableName) {
                continue
            }
            $trimmedTableName = $tableName.Trim()
            $quotedTable = Quote-Identifier $trimmedTableName
            $deletedRows = [int64](Get-SqlScalar -Query "SELECT COUNT(*) FROM $quotedTable WHERE id_users IS NOT NULL AND id_users NOT IN (SELECT id_users FROM keep_user_ids);")
            if ($deletedRows -gt 0) {
                Invoke-MysqlQuery -Query "DELETE FROM $quotedTable WHERE id_users IS NOT NULL AND id_users NOT IN (SELECT id_users FROM keep_user_ids);" | Out-Null
                $cleanupStats.Add("$($trimmedTableName):$deletedRows")
            }
        }

        $deletedUsers = [int64](Get-SqlScalar -Query 'SELECT COUNT(*) FROM users WHERE id_users NOT IN (SELECT id_users FROM keep_user_ids);')
        if ($deletedUsers -gt 0) {
            Invoke-MysqlQuery -Query 'DELETE FROM users WHERE id_users NOT IN (SELECT id_users FROM keep_user_ids);' | Out-Null
            $cleanupStats.Add("users:$deletedUsers")
        }
    }

    $afterFoto = [int64](Get-SqlScalar -Query 'SELECT COUNT(*) FROM foto;')
    $afterLogFoto = [int64](Get-SqlScalar -Query 'SELECT COUNT(*) FROM log_foto;')
    $afterUsers = 0
    if ($usersExists) {
        $afterUsers = [int64](Get-SqlScalar -Query 'SELECT COUNT(*) FROM users;')
    }

    $keptGaraIds = Invoke-MysqlQuery -Query "SELECT id_gara FROM keep_gara_ids ORDER BY $garaDateExpr DESC, id_gara DESC;"

    if (Test-Path $OutputDump) {
        Remove-Item $OutputDump -Force
    }

    Write-Host "Exporting trimmed dump..."
    Invoke-DockerQuiet -DockerArgs @(
        'exec', $ContainerName, 'sh', '-lc',
        "mysqldump -uroot -p$RootPassword --default-character-set=utf8mb4 --single-transaction --routines --triggers --set-gtid-purged=OFF $DatabaseName > /workspace/db/$outputFileName"
    )

    if (-not (Test-Path $OutputDump)) {
        throw "Trimmed dump was not created: $OutputDump"
    }

    $outputSizeBytes = (Get-Item $OutputDump).Length

    Write-Host "OriginalSizeBytes=$sourceSizeBytes"
    Write-Host "TrimmedSizeBytes=$outputSizeBytes"
    Write-Host "BeforeFoto=$beforeFoto"
    Write-Host "AfterFoto=$afterFoto"
    Write-Host "BeforeLogFoto=$beforeLogFoto"
    Write-Host "AfterLogFoto=$afterLogFoto"
    Write-Host "BeforeUsers=$beforeUsers"
    Write-Host "AfterUsers=$afterUsers"
    Write-Host ("KeptGaraIds=" + (($keptGaraIds | ForEach-Object { $_.Trim() }) -join ','))
    Write-Host ("DependencyCleanup=" + (($cleanupStats | Sort-Object) -join ';'))
    if (Test-Path $importErrorLogPath) {
        $importErrorCount = (Get-Item $importErrorLogPath).Length
        Write-Host "ImportErrorLogBytes=$importErrorCount"
    }
}
finally {
    & docker rm -f $ContainerName 1>$null 2>$null
    & docker volume rm $VolumeName 1>$null 2>$null
}