using System.Globalization;
using System.Text.Json;
using System.Text.Json.Nodes;
using Deal.Contracts.Integrations.Models;
using Deal.Modules.Kanban.Application.Models;
using Deal.Modules.Kanban.Application.Services;
using Deal.Modules.Pipeline.Application.Models;
using Deal.Modules.Pipeline.Application.Parse;
using Deal.SharedKernel.Utilities;

namespace Deal.Modules.Pipeline.Application.Services;

/// <summary>
/// Строгий маппинг JSON-ответа ИИ-классификатора в контрактный разбор карточки.
/// </summary>
public static class AiRawCardMapper
{
    private const int MaxTitleCodePoints = 140;

    private const int MaxFallbackTextCodePoints = 140;

    private const string BudgetAmountPattern = @"[0-9.,]+\s*[кkКK]?";

    // Строковые значения bool-полей, которые считаются «ложью».
    private static readonly IReadOnlySet<string> FalsyAnswerValues =
        new HashSet<string>(StringComparer.Ordinal) { "0", BoolText.False, "no", "нет", "null", "none" };

    // Регулярное выражение числа бюджета: число + необязательные «к»/валюта-суффиксы.
    private static readonly System.Text.RegularExpressions.Regex BudgetNumRe =
        new(@"\A" + BudgetAmountPattern + @"(?:руб|р|₽)?\z", System.Text.RegularExpressions.RegexOptions.CultureInvariant);

    /// <summary>
    /// Маппит JSON-ответ модели в контрактный разбор карточки.
    /// </summary>
    /// <param name="json">Сырой JSON-ответ модели (ClassifyReply.Json; типовую схему задаёт промпт).</param>
    /// <param name="text">Исходный текст сообщения.</param>
    /// <returns>Разбор: структурированный блок «О заявке»/суть, стек, бюджет, контакты, тип/спам/доска.</returns>
    /// <exception cref="JsonException">Ответ не объект/не разбирается — «ИИ не дал разбора» (ветка aiFail воркера).</exception>
    public static AiParsedCardDto Map(string json, string text)
    {
        JsonObject? root = JsonNode.Parse(json) as JsonObject
            ?? throw new JsonException("Ответ ИИ-классификатора — не JSON-объект (ok=true, но схема нарушена).");

        string title = MessageTextCleaner.CleanShort(ReadRawString(root, AiRawCardKeys.Title), MaxTitleCodePoints);
        if (title.Length == 0)
        {
            title = MessageTextCleaner.CleanShort(text, MaxFallbackTextCodePoints); // python L455 fallback
        }

        IReadOnlyList<string> stack = ReadStack(root);
        AiBudgetDto? budget = ReadBudget(root);
        IReadOnlyList<AiContactDto> contacts = ReadContacts(root, text);

        string? board = ReadRawString(root, AiRawCardKeys.Board).Trim();
        if (board.Length == 0)
        {
            board = null;
        }

        return new AiParsedCardDto(
            Title: title,
            Company: ReadNullableString(root, AiRawCardKeys.Company),
            Format: ReadNullableString(root, AiRawCardKeys.Format),
            Task: ReadNullableString(root, AiRawCardKeys.Task),
            Requirements: ReadItems(root, AiRawCardKeys.Requirements),
            Plus: ReadItems(root, AiRawCardKeys.Plus),
            Conditions: ReadNullableString(root, AiRawCardKeys.Conditions),
            Summary: ReadNullableString(root, AiRawCardKeys.Summary),
            Stack: stack,
            Budget: budget,
            Contacts: contacts,
            IsVacancy: ReadBool(root, AiRawCardKeys.IsVacancy),
            IsVacancyKnown: ReadBool(root, AiRawCardKeys.IsVacancyKnown), // false — воркер стемпит true после успешного ИИ
            IsSpam: ReadBool(root, AiRawCardKeys.IsSpam),
            Board: board);
    }

    private static string ReadRawString(JsonObject root, string field)
    {
        if (!root.TryGetPropertyValue(field, out JsonNode? node) || node is null)
        {
            return string.Empty;
        }

        return node is JsonValue value ? ValueToString(value) : string.Empty;
    }

    private static string? ReadNullableString(JsonObject root, string field)
    {
        string value = ReadRawString(root, field);
        return value.Length == 0 ? null : value;
    }

    private static bool ReadBool(JsonObject root, string field)
    {
        if (!root.TryGetPropertyValue(field, out JsonNode? node) || node is null)
        {
            return false;
        }

        if (node is not JsonValue value)
        {
            return false;
        }

        if (value.TryGetValue<bool>(out bool flag))
        {
            return flag;
        }

        if (value.TryGetValue<int>(out int number))
        {
            return number != 0;
        }

        if (value.TryGetValue<string>(out string? text))
        {
            string lower = (text ?? string.Empty).Trim().ToLowerInvariant();
            return lower.Length > 0 && !FalsyAnswerValues.Contains(lower);
        }

        return false;
    }

    private static IReadOnlyList<string>? ReadItems(JsonObject root, string field)
    {
        if (!root.TryGetPropertyValue(field, out JsonNode? node) || node is null)
        {
            return null;
        }

        IReadOnlyList<string> normalized = node is JsonValue scalarValue
            ? MessageListNormalizer.NormalizeList(NodeToString(scalarValue)) // python: строка разбивается по [;|\n]
            : node is JsonArray array
                ? MessageListNormalizer.NormalizeList(array.Select(NodeToString))
                : Array.Empty<string>();
        var result = new List<string>(normalized.Count);
        foreach (string item in normalized)
        {
            string cleaned = MessageTextCleaner.CleanShort(item);
            if (cleaned.Length > 0)
            {
                result.Add(cleaned);
            }
        }

        return result;
    }

    private static IReadOnlyList<string> ReadStack(JsonObject root)
    {
        if (!root.TryGetPropertyValue(AiRawCardKeys.Stack, out JsonNode? node) || node is null)
        {
            return Array.Empty<string>();
        }

        return node is JsonValue value
            ? MessageListNormalizer.NormalizeStack(ValueToString(value))
            : node is JsonArray array
                ? MessageListNormalizer.NormalizeStack(array.Select(NodeToString))
                : Array.Empty<string>();
    }

    private static AiBudgetDto? ReadBudget(JsonObject root)
    {
        if (!root.TryGetPropertyValue(AiRawCardKeys.Budget, out JsonNode? node) || node is not JsonObject budget)
        {
            return null;
        }

        string currency = ReadRawString(budget, AiRawCardKeys.Currency);
        if (currency.Length == 0)
        {
            currency = ReadRawString(budget, AiRawCardKeys.CurrencyShort); // ai.py L327: currency или cur
        }

        double? from = ParseBudgetBound(budget, AiRawCardKeys.From);
        double? to = ParseBudgetBound(budget, AiRawCardKeys.To);
        CardBudgetDto? normalized = BudgetNormalizer.Normalize(new BudgetRangeDto(from, to, currency));
        return normalized is null
            ? null
            : new AiBudgetDto(normalized.From, normalized.To, normalized.Cur);
    }

    private static double? ParseBudgetBound(JsonObject budget, string field)
    {
        if (!budget.TryGetPropertyValue(field, out JsonNode? node) || node is null)
        {
            return null;
        }

        if (node is JsonValue value && value.TryGetValue<double>(out double direct))
        {
            return direct == 0 ? null : direct; // python L313: x == 0 → None
        }

        string text = ReadRawString(budget, field).Replace("\u00a0", string.Empty).Replace(" ", string.Empty).ToLowerInvariant();
        if (text.Length == 0)
        {
            return null;
        }

        double multiplier = 1.0;
        if (text.EndsWith('к') || text.EndsWith('k'))
        {
            multiplier = 1000.0;
            text = text[..^1];
        }

        if (text.EndsWith("руб", StringComparison.Ordinal))
        {
            text = text[..^3];
        }
        else if (text.EndsWith('р') || text.EndsWith('₽'))
        {
            text = text[..^1];
        }

        if (!BudgetNumRe.IsMatch(text) || !double.TryParse(text.Replace(',', '.'), NumberStyles.Float, CultureInfo.InvariantCulture, out double amount))
        {
            return null;
        }

        double result = amount * multiplier;
        return result == 0 ? null : result;
    }

    private static IReadOnlyList<AiContactDto> ReadContacts(JsonObject root, string text)
    {
        List<string> candidates = new();
        if (root.TryGetPropertyValue(AiRawCardKeys.Contacts, out JsonNode? node) && node is not null)
        {
            if (node is JsonValue)
            {
                candidates.Add(ValueToString((JsonValue)node)); // строка: разобьётся разделителями ниже
            }
            else if (node is JsonArray array)
            {
                foreach (JsonNode? item in array)
                {
                    switch (item)
                    {
                        case null:
                            continue;
                        case JsonValue value:
                            candidates.Add(ValueToString(value));
                            break;
                        case JsonObject contactObject:
                        {
                            string value = ReadRawString(contactObject, AiRawCardKeys.Value);
                            if (value.Length > 0)
                            {
                                candidates.Add(value);
                            }

                            break;
                        }
                    }
                }
            }
            else if (candidates.Count == 0)
            {
                return Array.Empty<AiContactDto>();
            }
        }

        IReadOnlyList<CardContactDto> qualified = ContactsQualifier.Build(
            candidates.Count > 0 ? candidates : null, text);
        var result = new List<AiContactDto>(qualified.Count);
        foreach (CardContactDto contact in qualified)
        {
            result.Add(new AiContactDto(contact.Type, contact.Value));
        }

        return result;
    }

    private static string NodeToString(JsonNode? node)
        => node is JsonValue value ? ValueToString(value) : string.Empty;

    private static string ValueToString(JsonValue value)
    {
        if (value.TryGetValue<string>(out string? text))
        {
            return text ?? string.Empty;
        }

        if (value.TryGetValue<bool>(out bool flag))
        {
            return flag ? "true" : "false";
        }

        return value.ToJsonString().Trim('"');
    }
}