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

namespace QuestionsApi.Services;

public static class DynamicReviewExportCommand
{
    public static async Task<int> RunAsync(string[] args, TextWriter output)
    {
        static string Argument(string[] values, string name, string fallback = "")
        {
            var index = Array.FindIndex(values, value => value.Equals(name, StringComparison.OrdinalIgnoreCase));
            return index >= 0 && index + 1 < values.Length ? values[index + 1] : fallback;
        }
        var source = Argument(args, "--source", Path.Combine(AppContext.BaseDirectory, "content", "dynamic_questions"));
        var destination = Argument(args, "--output");
        if (!Directory.Exists(source) || string.IsNullOrWhiteSpace(destination))
        {
            await output.WriteLineAsync("Usage: export-dynamic-review --source <blueprints> --output <directory>");
            return 2;
        }
        var jsonOptions = new JsonSerializerOptions(JsonSerializerDefaults.Web)
            { PropertyNameCaseInsensitive = true, WriteIndented = 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), jsonOptions) ?? []);
        blueprints = blueprints.Where(value => value.IsPublished && value.QualityStandardVersion >= 2).ToList();

        var configuration = new ConfigurationBuilder()
            .AddJsonFile("appsettings.json", optional: true)
            .AddEnvironmentVariables()
            .Build();
        var authored = (await new QuestionStore(new MongoDatabaseProvider(configuration)).GetPublishedAsync())
            .OrderBy(value => value.ExternalId, StringComparer.Ordinal)
            .Take(blueprints.Count * 3)
            .ToList();
        if (authored.Count < blueprints.Count * 3)
            throw new InvalidOperationException("Not enough published authored questions for a balanced review packet.");

        var generator = new DynamicQuestionGenerator();
        var entries = new List<(Question Question, string Source, string Detail)>();
        foreach (var blueprint in blueprints)
            for (var seed = 0; seed < 3; seed++)
            {
                var generated = generator.Generate(blueprint, $"review-{seed}", $"review-{blueprint.ExternalId}-{seed}");
                entries.Add((generated.Question, "dynamic", $"{blueprint.ExternalId}:{generated.CaseFamilyId}"));
            }
        entries.AddRange(authored.Select(value => (value, "authored", value.ExternalId)));
        var ordered = entries.OrderBy(value => Convert.ToHexString(
            System.Security.Cryptography.SHA256.HashData(System.Text.Encoding.UTF8.GetBytes(value.Detail)))).ToList();

        Directory.CreateDirectory(destination);
        var packet = ordered.Select((entry, index) => new
        {
            reviewId = $"Q{index + 1:D2}",
            entry.Question.Stem,
            entry.Question.LeadIn,
            entry.Question.Choices,
            entry.Question.Labs,
            entry.Question.Explanation,
            entry.Question.ChoiceExplanations,
            entry.Question.ReviewFollowups,
            entry.Question.WrongAnswerFollowups,
            scoring = new { realism = 0, distractors = 0, explanation = 0, step3Relevance = 0, criticalIssue = "", predictedSource = "" }
        });
        var key = ordered.Select((entry, index) => new { reviewId = $"Q{index + 1:D2}", entry.Source, entry.Detail });
        await File.WriteAllTextAsync(Path.Combine(destination, "review-packet.json"), JsonSerializer.Serialize(packet, jsonOptions));
        await File.WriteAllTextAsync(Path.Combine(destination, "answer-key.json"), JsonSerializer.Serialize(key, jsonOptions));
        await output.WriteLineAsync($"Exported {ordered.Count} blinded questions to {destination}.");
        return 0;
    }
}