using Microsoft.Extensions.Configuration;
using QuestionsApi.Models;
using System.Text.Json;

namespace QuestionsApi.Services;

public static class DynamicBlueprintCommand
{
    public static async Task<int> RunAsync(string[] args, TextWriter output)
    {
        var apply = args.Contains("--apply", StringComparer.OrdinalIgnoreCase);
        var sourceIndex = Array.FindIndex(args, value => value.Equals("--source", StringComparison.OrdinalIgnoreCase));
        var source = sourceIndex >= 0 && sourceIndex + 1 < args.Length
            ? args[sourceIndex + 1]
            : Path.Combine(AppContext.BaseDirectory, "content", "dynamic_questions");
        if (!Directory.Exists(source))
        {
            await output.WriteLineAsync($"Dynamic blueprint directory not found: {source}");
            return 2;
        }
        var json = new JsonSerializerOptions(JsonSerializerDefaults.Web) { PropertyNameCaseInsensitive = true };
        var blueprints = new List<DynamicQuestionBlueprint>();
        foreach (var file in Directory.EnumerateFiles(source, "*.json", SearchOption.AllDirectories))
            blueprints.AddRange(JsonSerializer.Deserialize<List<DynamicQuestionBlueprint>>(await File.ReadAllTextAsync(file), json) ?? []);

        var generator = new DynamicQuestionGenerator();
        var generatedVariants = 0;
        foreach (var blueprint in blueprints)
        {
            var error = DynamicQuestionGenerator.Validate(blueprint);
            if (error is not null)
                throw new InvalidDataException($"{blueprint.ExternalId} v{blueprint.Version}: {error}");
            var validationSeeds = blueprint.QualityStandardVersion >= 2 ? 10_000 : 1_000;
            for (var seed = 0; seed < validationSeeds; seed++)
                generator.Generate(blueprint, seed.ToString(), seed.ToString());
            generatedVariants += validationSeeds;
        }
        await output.WriteLineAsync($"Validated {blueprints.Count} blueprints across {generatedVariants:N0} generated variants.");
        if (!apply)
        {
            await output.WriteLineAsync("Dry run only. Pass --apply to publish.");
            return 0;
        }
        var configuration = new ConfigurationBuilder()
            .AddJsonFile("appsettings.json", optional: true)
            .AddEnvironmentVariables()
            .Build();
        var store = new DynamicQuestionStore(new MongoDatabaseProvider(configuration));
        var result = await store.UpsertBlueprintsAsync(blueprints);
        await output.WriteLineAsync($"Promotion complete: {result.Inserted} inserted, {result.Unchanged} unchanged.");
        return 0;
    }
}