param(
    [string]$ArchiveListPath = "",
    [string]$CacheRoot = "",
    [string]$SQLiteDllPath = $env:ISPHERE_MSGLIB_SQLITE_DLL,
    [string]$DbPath = $env:ISPHERE_MSGLIB_DB,
    [string]$Password = "123",
    [switch]$SkipDb
)

$ErrorActionPreference = "Stop"
Set-StrictMode -Version Latest

$repo = (Resolve-Path -LiteralPath (Join-Path $PSScriptRoot "..")).Path

function Add-Count([hashtable]$Map, [string]$Key, [int]$Increment = 1) {
    if ([string]::IsNullOrWhiteSpace($Key)) { return }
    if ($Map.ContainsKey($Key)) {
        $Map[$Key] = [int]$Map[$Key] + $Increment
    }
    else {
        $Map[$Key] = $Increment
    }
}

function Get-Sha256Text([string]$Value) {
    $sha = [System.Security.Cryptography.SHA256]::Create()
    try {
        $bytes = [System.Text.Encoding]::UTF8.GetBytes($Value)
        $hash = $sha.ComputeHash($bytes)
        return (($hash | ForEach-Object { $_.ToString("x2") }) -join "")
    }
    finally {
        $sha.Dispose()
    }
}

function Normalize-FileName([string]$Value) {
    if ([string]::IsNullOrWhiteSpace($Value)) { return "" }
    $leaf = ($Value -split '[\\/]')[-1]
    return $leaf.Trim().ToLowerInvariant()
}

function Normalize-Extension([string]$Value) {
    if ([string]::IsNullOrWhiteSpace($Value)) { return "" }
    $extension = $Value.Trim().ToLowerInvariant()
    if ($extension -match '^\.[a-z0-9]{1,8}$') { return $extension }
    return ".other"
}

function New-EmptyCacheSummary {
    return [ordered]@{
        checked = $false
        candidate_count = 0
        extension_counts = @{}
        hash_dir_length_counts = @{}
        hash_dir_value_hash_counts = @{}
        filename_hash_counts = @{}
        filename_size_hash_counts = @{}
        has_size_data = $false
    }
}

function Add-CacheCandidate($Summary, [string]$Name, [Nullable[Int64]]$Size, [string]$HashDir) {
    $normalizedName = Normalize-FileName $Name
    if ($normalizedName -eq "") { return }
    $extension = Normalize-Extension ([System.IO.Path]::GetExtension($normalizedName))
    if ($extension -ne "") {
        Add-Count $Summary.extension_counts $extension
    }
    if (-not [string]::IsNullOrWhiteSpace($HashDir)) {
        Add-Count $Summary.hash_dir_length_counts ([string]$HashDir.Length)
        Add-Count $Summary.hash_dir_value_hash_counts (Get-Sha256Text $HashDir.ToLowerInvariant())
    }
    Add-Count $Summary.filename_hash_counts (Get-Sha256Text $normalizedName)
    if ($null -ne $Size -and $Size.Value -ge 0) {
        $Summary["has_size_data"] = $true
        Add-Count $Summary.filename_size_hash_counts (Get-Sha256Text ($normalizedName + "|" + $Size.Value))
    }
    $Summary["candidate_count"] = [int]$Summary["candidate_count"] + 1
}

function Get-HashDirFromPathText([string]$Value) {
    $match = [regex]::Match($Value, '(?i)(?:^|[\\/])importal[\\/]([0-9a-f]{32,})(?:[\\/])')
    if ($match.Success) {
        return $match.Groups[1].Value.ToLowerInvariant()
    }
    return ""
}

function Read-CacheSummaryFromArchiveList([string]$Path) {
    if (-not (Test-Path -LiteralPath $Path)) {
        throw "ArchiveListPath not found"
    }
    $summary = New-EmptyCacheSummary
    $summary["checked"] = $true
    foreach ($line in Get-Content -LiteralPath $Path) {
        $text = [string]$line
        $hashDir = Get-HashDirFromPathText $text
        if ($hashDir -eq "") { continue }
        Add-CacheCandidate $summary $text $null $hashDir
    }
    return $summary
}

function Read-CacheSummaryFromRoot([string]$Path) {
    if (-not (Test-Path -LiteralPath $Path)) {
        throw "CacheRoot not found"
    }
    $summary = New-EmptyCacheSummary
    $summary["checked"] = $true
    foreach ($file in Get-ChildItem -LiteralPath $Path -File -Recurse) {
        $hashDir = Get-HashDirFromPathText $file.FullName
        if ($hashDir -eq "") { continue }
        Add-CacheCandidate $summary $file.Name ([Int64]$file.Length) $hashDir
    }
    return $summary
}

function Convert-CountObjectToHashtable($Value) {
    $map = @{}
    if ($null -eq $Value) { return $map }
    if ($Value -is [System.Collections.IDictionary]) {
        foreach ($key in $Value.Keys) {
            $map[[string]$key] = [int]$Value[$key]
        }
        return $map
    }
    foreach ($property in $Value.PSObject.Properties) {
        $map[$property.Name] = [int]$property.Value
    }
    return $map
}

function Count-Intersections([hashtable]$Left, [hashtable]$Right) {
    $count = 0
    foreach ($key in $Left.Keys) {
        if ($Right.ContainsKey($key)) {
            $count += [Math]::Min([int]$Left[$key], [int]$Right[$key])
        }
    }
    return $count
}

function Count-UniqueIntersections([hashtable]$Left, [hashtable]$Right) {
    $count = 0
    foreach ($key in $Left.Keys) {
        if ($Right.ContainsKey($key) -and [int]$Left[$key] -eq 1 -and [int]$Right[$key] -eq 1) {
            $count++
        }
    }
    return $count
}

function Invoke-ReceiveFileRecordProbe([string]$SQLiteDll, [string]$Database, [string]$DbPassword) {
    if (-not (Test-Path -LiteralPath $SQLiteDll)) {
        throw "SQLite DLL not found"
    }
    if (-not (Test-Path -LiteralPath $Database)) {
        throw "MsgLib DB not found"
    }

    $tempDir = Join-Path $repo ("runs\file-cache-mapping-db-probe-" + [guid]::NewGuid().ToString("N"))
    $source = Join-Path $tempDir "ReceiveFileRecordProbe.cs"
    $exe = Join-Path $tempDir "ReceiveFileRecordProbe.exe"
    $sqliteCopy = Join-Path $tempDir "System.Data.SQLite.dll"
    $csc = "$env:WINDIR\Microsoft.NET\Framework\v4.0.30319\csc.exe"
    if (-not (Test-Path -LiteralPath $csc)) {
        throw "32-bit .NET Framework csc.exe v4.0.30319 not found"
    }

    try {
        New-Item -ItemType Directory -Force -Path $tempDir | Out-Null
        Copy-Item -LiteralPath $SQLiteDll -Destination $sqliteCopy -Force
        @'
using System;
using System.Collections.Generic;
using System.Data.Common;
using System.IO;
using System.Reflection;
using System.Security.Cryptography;
using System.Text;
using System.Web.Script.Serialization;

internal static class ReceiveFileRecordProbe
{
    private static int Main(string[] args)
    {
        try
        {
            string sqliteDllPath = args[0];
            string dbPath = args[1];
            string password = args.Length > 2 ? args[2] : "123";
            AppDomain.CurrentDomain.AssemblyResolve += delegate(object sender, ResolveEventArgs eventArgs)
            {
                if (eventArgs.Name.StartsWith("System.Data.SQLite", StringComparison.OrdinalIgnoreCase))
                {
                    return Assembly.LoadFrom(sqliteDllPath);
                }
                return null;
            };

            Assembly sqliteAssembly = Assembly.LoadFrom(sqliteDllPath);
            Type factoryType = sqliteAssembly.GetType("System.Data.SQLite.SQLiteFactory", true);
            FieldInfo instanceField = factoryType.GetField("Instance", BindingFlags.Public | BindingFlags.Static);
            DbProviderFactory factory = (DbProviderFactory)instanceField.GetValue(null);

            var result = NewResult();
            using (DbConnection connection = factory.CreateConnection())
            {
                connection.ConnectionString = "Data Source=" + dbPath + ";Version=3;Read Only=True;Password=" + password + ";";
                connection.Open();
                ExecuteNonQuery(connection, "PRAGMA query_only=ON");
                if (!TableExists(connection, "TD_ReceiveFileRecord"))
                {
                    PrintJson(result);
                    return 0;
                }
                result["table_available"] = true;
                HashSet<string> columns = ReadColumns(connection, "TD_ReceiveFileRecord");
                string msgColumn = ExistingColumn(columns, "ReceiveMsgGuid");
                string nameColumn = ExistingColumn(columns, "FileName");
                string sizeColumn = ExistingColumn(columns, "FileSize", "Size");
                string sourceColumn = ExistingColumn(columns, "SourceID", "FileGuid", "FileId");
                if (nameColumn == "")
                {
                    PrintJson(result);
                    return 0;
                }

                string sql = "select " +
                    SelectColumn(msgColumn, "receive_msg_guid") + ", " +
                    SelectColumn(nameColumn, "file_name") + ", " +
                    SelectColumn(sizeColumn, "size_bytes") + ", " +
                    SelectColumn(sourceColumn, "source_id") +
                    " from " + QuoteIdent("TD_ReceiveFileRecord") + " limit 100000";

                using (DbCommand command = connection.CreateCommand())
                {
                    command.CommandText = sql;
                    using (DbDataReader reader = command.ExecuteReader())
                    {
                        while (reader.Read())
                        {
                            result["record_count"] = (int)result["record_count"] + 1;
                            string receiveMsgGuid = ReaderString(reader, "receive_msg_guid");
                            string fileName = SafeFileName(ReaderString(reader, "file_name"));
                            long size = ReaderInt64(reader, "size_bytes");
                            string sourceId = ReaderString(reader, "source_id").Trim().ToLowerInvariant();

                            if (receiveMsgGuid.Trim() != "") result["receive_msg_guid_present_count"] = (int)result["receive_msg_guid_present_count"] + 1;
                            if (fileName.Trim() != "") result["filename_present_count"] = (int)result["filename_present_count"] + 1;
                            if (size > 0) result["size_present_count"] = (int)result["size_present_count"] + 1;
                            if (sourceId != "") result["source_id_present_count"] = (int)result["source_id_present_count"] + 1;

                            string normalizedName = fileName.Trim().ToLowerInvariant();
                            if (normalizedName != "")
                            {
                                AddCount((Dictionary<string, object>)result["extension_counts"], SafeExtension(Path.GetExtension(normalizedName)));
                                AddCount((Dictionary<string, object>)result["filename_hash_counts"], Sha256(normalizedName));
                                if (size > 0) AddCount((Dictionary<string, object>)result["filename_size_hash_counts"], Sha256(normalizedName + "|" + size.ToString()));
                            }
                            if (sourceId != "")
                            {
                                AddCount((Dictionary<string, object>)result["source_id_hash_counts"], Sha256(sourceId));
                                if (IsHexLike(sourceId)) result["source_id_hash_shape_count"] = (int)result["source_id_hash_shape_count"] + 1;
                            }
                        }
                    }
                }
            }
            PrintJson(result);
            return 0;
        }
        catch (Exception ex)
        {
            Console.Error.WriteLine(ex.GetType().Name + ": " + ex.Message);
            return 1;
        }
    }

    private static Dictionary<string, object> NewResult()
    {
        return new Dictionary<string, object>
        {
            { "table_available", false },
            { "record_count", 0 },
            { "filename_present_count", 0 },
            { "size_present_count", 0 },
            { "source_id_present_count", 0 },
            { "receive_msg_guid_present_count", 0 },
            { "source_id_hash_shape_count", 0 },
            { "extension_counts", new Dictionary<string, object>() },
            { "filename_hash_counts", new Dictionary<string, object>() },
            { "filename_size_hash_counts", new Dictionary<string, object>() },
            { "source_id_hash_counts", new Dictionary<string, object>() }
        };
    }

    private static void PrintJson(Dictionary<string, object> value)
    {
        Console.WriteLine(new JavaScriptSerializer().Serialize(value));
    }

    private static void AddCount(Dictionary<string, object> map, string key)
    {
        if (string.IsNullOrWhiteSpace(key)) return;
        if (map.ContainsKey(key)) map[key] = (int)map[key] + 1;
        else map[key] = 1;
    }

    private static bool TableExists(DbConnection connection, string table)
    {
        using (DbCommand command = connection.CreateCommand())
        {
            command.CommandText = "select count(*) from sqlite_master where type='table' and name=@name";
            DbParameter parameter = command.CreateParameter();
            parameter.ParameterName = "@name";
            parameter.Value = table;
            command.Parameters.Add(parameter);
            return Convert.ToInt32(command.ExecuteScalar()) > 0;
        }
    }

    private static HashSet<string> ReadColumns(DbConnection connection, string table)
    {
        var columns = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
        using (DbCommand command = connection.CreateCommand())
        {
            command.CommandText = "pragma table_info(" + QuoteIdent(table) + ")";
            using (DbDataReader reader = command.ExecuteReader())
            {
                while (reader.Read()) columns.Add(Convert.ToString(reader["name"]));
            }
        }
        return columns;
    }

    private static string ExistingColumn(HashSet<string> columns, params string[] names)
    {
        foreach (string name in names)
        {
            if (!string.IsNullOrWhiteSpace(name) && columns.Contains(name)) return name;
        }
        return "";
    }

    private static string SelectColumn(string column, string alias)
    {
        if (string.IsNullOrWhiteSpace(column)) return "'' as " + QuoteIdent(alias);
        return QuoteIdent(column) + " as " + QuoteIdent(alias);
    }

    private static string QuoteIdent(string value)
    {
        return "\"" + value.Replace("\"", "\"\"") + "\"";
    }

    private static string ReaderString(DbDataReader reader, string column)
    {
        object value = reader[column];
        if (value == null || value == DBNull.Value) return "";
        return Convert.ToString(value);
    }

    private static long ReaderInt64(DbDataReader reader, string column)
    {
        object value = reader[column];
        if (value == null || value == DBNull.Value) return 0;
        long parsed;
        if (long.TryParse(Convert.ToString(value), out parsed)) return parsed;
        return 0;
    }

    private static string SafeFileName(string value)
    {
        if (string.IsNullOrWhiteSpace(value)) return "";
        try { return Path.GetFileName(value); }
        catch
        {
            int slash = Math.Max(value.LastIndexOf('/'), value.LastIndexOf('\\'));
            if (slash >= 0 && slash + 1 < value.Length) return value.Substring(slash + 1);
            return value;
        }
    }

    private static string SafeExtension(string value)
    {
        if (string.IsNullOrWhiteSpace(value)) return "";
        string extension = value.Trim().ToLowerInvariant();
        if (extension.Length < 2 || extension.Length > 9) return ".other";
        if (extension[0] != '.') return ".other";
        for (int i = 1; i < extension.Length; i++)
        {
            char c = extension[i];
            bool ok = (c >= 'a' && c <= 'z') || (c >= '0' && c <= '9');
            if (!ok) return ".other";
        }
        return extension;
    }

    private static bool IsHexLike(string value)
    {
        if (value.Length < 16) return false;
        foreach (char c in value)
        {
            bool ok = (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F');
            if (!ok) return false;
        }
        return true;
    }

    private static string Sha256(string value)
    {
        using (SHA256 sha = SHA256.Create())
        {
            byte[] hash = sha.ComputeHash(Encoding.UTF8.GetBytes(value));
            var builder = new StringBuilder(hash.Length * 2);
            foreach (byte b in hash) builder.Append(b.ToString("x2"));
            return builder.ToString();
        }
    }

    private static void ExecuteNonQuery(DbConnection connection, string sql)
    {
        using (DbCommand command = connection.CreateCommand())
        {
            command.CommandText = sql;
            command.ExecuteNonQuery();
        }
    }
}
'@ | Set-Content -LiteralPath $source -Encoding UTF8

        & $csc `
            /nologo `
            /target:exe `
            /platform:x86 `
            /optimize+ `
            /warn:0 `
            /out:$exe `
            /reference:System.dll `
            /reference:System.Core.dll `
            /reference:System.Data.dll `
            /reference:System.Web.Extensions.dll `
            /reference:$sqliteCopy `
            $source | Out-Null
        if ($LASTEXITCODE -ne 0) {
            throw "ReceiveFileRecordProbe compilation failed"
        }
        @'
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <startup useLegacyV2RuntimeActivationPolicy="true">
    <supportedRuntime version="v4.0" />
    <supportedRuntime version="v2.0.50727" />
  </startup>
</configuration>
'@ | Set-Content -LiteralPath ($exe + ".config") -Encoding UTF8

        $output = & $exe $sqliteCopy $Database $DbPassword
        if ($LASTEXITCODE -ne 0) {
            throw "ReceiveFileRecordProbe failed"
        }
        return $output | ConvertFrom-Json
    }
    finally {
        if (Test-Path -LiteralPath $tempDir) {
            Remove-Item -LiteralPath $tempDir -Recurse -Force
        }
    }
}

$cacheSummary = New-EmptyCacheSummary
if (-not [string]::IsNullOrWhiteSpace($ArchiveListPath)) {
    $cacheSummary = Read-CacheSummaryFromArchiveList $ArchiveListPath
}
elseif (-not [string]::IsNullOrWhiteSpace($CacheRoot)) {
    $cacheSummary = Read-CacheSummaryFromRoot $CacheRoot
}

$dbChecked = $false
$dbProbe = [ordered]@{
    table_available = $false
    record_count = 0
    filename_present_count = 0
    size_present_count = 0
    source_id_present_count = 0
    receive_msg_guid_present_count = 0
    source_id_hash_shape_count = 0
    extension_counts = @{}
    filename_hash_counts = @{}
    filename_size_hash_counts = @{}
    source_id_hash_counts = @{}
}

if (-not $SkipDb) {
    if ([string]::IsNullOrWhiteSpace($SQLiteDllPath) -or [string]::IsNullOrWhiteSpace($DbPath)) {
        throw "MsgLib DB probe requires SQLiteDllPath and DbPath, or pass -SkipDb"
    }
    $dbProbe = Invoke-ReceiveFileRecordProbe $SQLiteDllPath $DbPath $Password
    $dbChecked = $true
}

$dbFilenameHashes = Convert-CountObjectToHashtable $dbProbe.filename_hash_counts
$dbFilenameSizeHashes = Convert-CountObjectToHashtable $dbProbe.filename_size_hash_counts
$dbSourceIDHashes = Convert-CountObjectToHashtable $dbProbe.source_id_hash_counts
$cacheFilenameHashes = [hashtable]$cacheSummary["filename_hash_counts"]
$cacheFilenameSizeHashes = [hashtable]$cacheSummary["filename_size_hash_counts"]
$cacheHashDirValueHashes = [hashtable]$cacheSummary["hash_dir_value_hash_counts"]

$filenameOnlyMatches = Count-Intersections $dbFilenameHashes $cacheFilenameHashes
$filenameSizeMatches = Count-Intersections $dbFilenameSizeHashes $cacheFilenameSizeHashes
$uniqueFilenameSizeMatches = Count-UniqueIntersections $dbFilenameSizeHashes $cacheFilenameSizeHashes
$sourceIDHashDirMatches = Count-Intersections $dbSourceIDHashes $cacheHashDirValueHashes

$mappingValidated = ($uniqueFilenameSizeMatches -gt 0 -and [bool]$cacheSummary["has_size_data"])
$recommendedNextNode = "additional evidence request"
if ($mappingValidated) {
    $recommendedNextNode = "R4 cache-file resolver candidate"
}
elseif ($filenameOnlyMatches -gt 0 -or $sourceIDHashDirMatches -gt 0) {
    $recommendedNextNode = "additional evidence request: collect file size or cache root metadata"
}

[ordered]@{
    ok = $true
    verification = "file_cache_mapping"
    db_checked = $dbChecked
    db_table_available = [bool]$dbProbe.table_available
    db_record_count = [int]$dbProbe.record_count
    db_filename_present_count = [int]$dbProbe.filename_present_count
    db_size_present_count = [int]$dbProbe.size_present_count
    db_source_id_present_count = [int]$dbProbe.source_id_present_count
    db_receive_msg_guid_present_count = [int]$dbProbe.receive_msg_guid_present_count
    db_source_id_hash_shape_count = [int]$dbProbe.source_id_hash_shape_count
    db_extension_counts = $dbProbe.extension_counts
    cache_checked = [bool]$cacheSummary["checked"]
    cache_candidate_count = [int]$cacheSummary["candidate_count"]
    cache_extension_counts = $cacheSummary["extension_counts"]
    hash_dir_length_counts = $cacheSummary["hash_dir_length_counts"]
    filename_only_match_count = $filenameOnlyMatches
    filename_size_match_count = $filenameSizeMatches
    unique_filename_size_match_count = $uniqueFilenameSizeMatches
    source_id_hash_dir_match_count = $sourceIDHashDirMatches
    mapping_validated = $mappingValidated
    recommended_next_node = $recommendedNextNode
    raw_paths_printed = $false
    file_contents_read = $false
    file_paths_returned = $false
    raw_rows_returned = $false
    message_body_values_printed = $false
} | ConvertTo-Json -Depth 8 -Compress