using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging.Abstractions;
using SVSim.Bootstrap.Importers;
using SVSim.Database;

namespace SVSim.Bootstrap;

public static class Program
{
    private const string DefaultConnectionString =
        "Host=localhost;Database=svsim;Username=postgres;password=postgres";

    public static async Task<int> Main(string[] args)
    {
        if (args.Length > 0 && (args[0] is "--help" or "-h"))
        {
            PrintUsage();
            return 1;
        }

        var opts = ParseArgs(args);
        if (opts is null)
        {
            PrintUsage();
            return 1;
        }

        if (opts.SkipCards && opts.SkipGlobals)
        {
            Console.Error.WriteLine("Both --skip-cards and --skip-globals set; nothing to do.");
            return 1;
        }

        Console.WriteLine($"[Bootstrap] Connection: {RedactPassword(opts.ConnectionString)}");
        Console.WriteLine($"[Bootstrap] Cards file:  {opts.CardsFile}");
        Console.WriteLine($"[Bootstrap] Captures:    {opts.CapturesDir}");

        var dbOptions = new DbContextOptionsBuilder<SVSimDbContext>()
            .UseNpgsql(opts.ConnectionString)
            .Options;

        await using var context = new SVSimDbContext(NullLogger<SVSimDbContext>.Instance, dbOptions);

        // Bootstrap applies pending migrations first so it can be the very first thing run after
        // `dotnet ef migrations add` — no need to start the server too.
        Console.WriteLine("[Bootstrap] Applying pending migrations...");
        await context.Database.MigrateAsync();

        if (!opts.SkipCards)
        {
            await new CardImporter().ImportAsync(context, opts.CardsFile);
        }
        else
        {
            Console.WriteLine("[Bootstrap] --skip-cards set; skipping card import.");
        }

        if (!opts.SkipGlobals)
        {
            await new GlobalsImporter().ImportAllAsync(context, opts.CapturesDir);
        }
        else
        {
            Console.WriteLine("[Bootstrap] --skip-globals set; skipping globals import.");
        }

        Console.WriteLine("[Bootstrap] Complete.");
        return 0;
    }

    private static BootstrapOptions? ParseArgs(string[] args)
    {
        string? dataDir = null;
        string? cards = null;
        string? captures = null;
        string? connection = null;
        bool skipCards = false;
        bool skipGlobals = false;
        string? positionalCards = null;

        for (int i = 0; i < args.Length; i++)
        {
            string a = args[i];
            switch (a)
            {
                case "--data-dir": dataDir = NextArg(args, ref i); break;
                case "--cards": cards = NextArg(args, ref i); break;
                case "--captures": captures = NextArg(args, ref i); break;
                case "--connection-string": connection = NextArg(args, ref i); break;
                case "--skip-cards": skipCards = true; break;
                case "--skip-globals": skipGlobals = true; break;
                default:
                    // Back-compat: legacy positional form `svsim-card-import <cards.json> [connection]`.
                    if (positionalCards is null && !a.StartsWith('-')) positionalCards = a;
                    else if (connection is null && !a.StartsWith('-')) connection = a;
                    else { Console.Error.WriteLine($"Unknown argument: {a}"); return null; }
                    break;
            }
        }

        // Resolution order:
        //   --cards beats --data-dir/cards.json beats legacy positional;
        //   --captures beats --data-dir/prod-captures beats Bootstrap/Data/prod-captures (shipped default).
        string baseDir = AppContext.BaseDirectory;
        string shippedCaptures = Path.Combine(baseDir, "Data", "prod-captures");

        string cardsFile = cards
            ?? (dataDir is not null ? Path.Combine(dataDir, "cards.json") : null)
            ?? positionalCards
            ?? "data_dumps/cards.json";

        // Resolve captures dir, falling back to the shipped copy if the data-dir path is unset
        // OR points at a missing folder. (Common case: user has cards.json in data_dumps/ but
        // hasn't copied prod-captures/ there — the shipped snapshot is the source of truth.)
        string? capturesCandidate = captures
            ?? (dataDir is not null ? Path.Combine(dataDir, "prod-captures") : null);
        string capturesDir = capturesCandidate is not null && Directory.Exists(capturesCandidate)
            ? capturesCandidate
            : shippedCaptures;

        string connStr = connection
            ?? Environment.GetEnvironmentVariable("NPGSQL_CONNECTION")
            ?? DefaultConnectionString;

        return new BootstrapOptions(cardsFile, capturesDir, connStr, skipCards, skipGlobals);
    }

    private static string NextArg(string[] args, ref int i)
    {
        if (i + 1 >= args.Length) throw new ArgumentException($"Missing value for {args[i]}");
        return args[++i];
    }

    private static string RedactPassword(string conn) =>
        System.Text.RegularExpressions.Regex.Replace(conn, "(?i)(password=)[^;]+", "$1***");

    private static void PrintUsage()
    {
        Console.Error.WriteLine(
            "Usage: svsim-bootstrap [options]\n" +
            "\n" +
            "  --data-dir <path>           Directory containing cards.json and prod-captures/\n" +
            "                              (default: ./data_dumps relative to working dir)\n" +
            "  --cards <file>              Override path to cards.json\n" +
            "  --captures <dir>            Override path to prod-captures directory\n" +
            "                              (default: shipped Data/prod-captures next to the binary)\n" +
            "  --connection-string <conn>  Postgres connection (or NPGSQL_CONNECTION env var,\n" +
            $"                              then \"{DefaultConnectionString}\")\n" +
            "  --skip-cards                Skip card import (re-run globals only)\n" +
            "  --skip-globals              Skip globals import (cards only — legacy behavior)\n" +
            "\n" +
            "Back-compat: `svsim-bootstrap <cards.json> [connection]` still works (positional).");
    }

    private sealed record BootstrapOptions(
        string CardsFile,
        string CapturesDir,
        string ConnectionString,
        bool SkipCards,
        bool SkipGlobals);
}