using System.IO;
using System.Text.Json;
using CliFx;
using CliFx.Attributes;
using CliFx.Exceptions;
using CliFx.Infrastructure;
using ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.Import;

namespace ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.Cli.Commands;

/// <summary>
///     ablegacy-11 / #254 — read an RSLogix 500 / 5 "Database Export" CSV and emit either an
///     <c>appsettings.json</c> tag fragment or a summary line. Avoids the AbLegacyCommandBase
///     hierarchy because import is a purely-offline operation: no gateway, no driver, no
///     timeout. Mirrors the
///     <a href="https://github.com/dohertj2/lmxopcua/issues/254">#254 plan section</a>'s CLI
///     specification verbatim.
/// </summary>
[Command("import-rslogix", Description =
    "Read an RSLogix 500/5 CSV symbol export and emit a JSON tag fragment for appsettings.json. " +
    "Binary .RSS / .RSP project files are out of scope (see docs/drivers/AbLegacy-RSLogix-Import.md).")]
public sealed class ImportRslogixCommand : ICommand
{
    [CommandOption("file", 'f', Description =
        "Path to the RSLogix CSV export. RFC 4180-ish format with header columns " +
        "Symbol,Address,Description,DataType,Scope; quoted fields + doubled-quote escapes " +
        "are honoured; comment lines starting with ; or # are skipped.",
        IsRequired = true)]
    public string File { get; init; } = default!;

    [CommandOption("device", 'd', Description =
        "Canonical AB Legacy gateway URI (ab://host[:port]/cip-path) every imported tag " +
        "binds to. Required even though import is offline — the resulting tag definitions " +
        "carry the gateway address as their DeviceHostAddress.",
        IsRequired = true)]
    public string Device { get; init; } = default!;

    [CommandOption("emit", Description =
        "Output shape: 'appsettings-fragment' (default) emits a JSON object with a Tags array " +
        "ready to paste into appsettings.json; 'summary' emits one human-readable counter line.")]
    public string Emit { get; init; } = "appsettings-fragment";

    [CommandOption("output", 'o', Description =
        "Optional output file. When omitted, the result goes to stdout.")]
    public string? Output { get; init; }

    [CommandOption("scope", Description =
        "Optional Scope filter — match the row's Scope column against this value " +
        "case-insensitively. Common values: 'Global', 'Local:1', 'Local:2'. Rows with " +
        "no Scope column count as Global.")]
    public string? Scope { get; init; }

    [CommandOption("max-rows", Description =
        "Defensive cap on the number of rows imported. Beyond the cap the parser stops " +
        "and emits a warning; useful for dry-running a large export against the CLI.")]
    public int? MaxRows { get; init; }

    [CommandOption("strict", Description =
        "When set, the first malformed row throws and the CLI exits non-zero. Default is " +
        "permissive (skip + log).")]
    public bool Strict { get; init; }

    public async ValueTask ExecuteAsync(IConsole console)
    {
        if (!System.IO.File.Exists(File))
        {
            // Surface a clean exit-code-1 with a one-line error rather than letting
            // FileNotFoundException bubble up through CliFx's default exception path —
            // the CLI tests and operators both prefer `import-rslogix --file missing.csv`
            // to print "file not found" rather than a stack trace.
            throw new CommandException($"RSLogix CSV not found: {File}", exitCode: 1);
        }

        var opts = new ImportOptions(
            ScopeFilter: Scope,
            MaxRowsToImport: MaxRows,
            IgnoreInvalid: !Strict);

        RsLogixImportResult result;
        using (var stream = System.IO.File.OpenRead(File))
        {
            var importer = new RsLogixSymbolImport();
            result = importer.Parse(stream, Device, opts);
        }

        var emit = Emit?.Trim().ToLowerInvariant();
        var payload = emit switch
        {
            "summary" => FormatSummary(result),
            "appsettings-fragment" or null or "" => FormatFragment(result),
            _ => throw new CommandException(
                $"Unknown --emit value '{Emit}'. Use 'appsettings-fragment' or 'summary'.",
                exitCode: 2),
        };

        if (Output is { Length: > 0 })
        {
            await System.IO.File.WriteAllTextAsync(Output, payload);
            await console.Output.WriteLineAsync(
                $"Wrote {result.ParsedCount} tag(s) to {Output} (skipped={result.SkippedCount}, errors={result.ErrorCount}).");
        }
        else
        {
            await console.Output.WriteLineAsync(payload);
        }
    }

    /// <summary>
    ///     Serialise the imported tag list as a JSON fragment shaped like the
    ///     <c>AbLegacyDriverConfigDto</c>'s <c>Tags</c> array — drop straight into the
    ///     <c>appsettings.json</c> driver config under
    ///     <c>Drivers/&lt;instance&gt;/Config/Tags</c>.
    /// </summary>
    internal static string FormatFragment(RsLogixImportResult result)
    {
        var tags = result.Tags.Select(t => new
        {
            Name = t.Name,
            DeviceHostAddress = t.DeviceHostAddress,
            Address = t.Address,
            DataType = t.DataType.ToString(),
            Writable = t.Writable,
        }).ToArray();
        var doc = new { Tags = tags };
        return JsonSerializer.Serialize(doc, new JsonSerializerOptions { WriteIndented = true });
    }

    private static string FormatSummary(RsLogixImportResult result) =>
        $"Imported {result.ParsedCount} tag(s), skipped {result.SkippedCount}, errors {result.ErrorCount}.";
}