using BakeryErp.Infrastructure.Database;

namespace BakeryErp.Infrastructure.Repositories;

public sealed class OcrDocumentRepository
{
    private readonly DatabaseOptions _options;

    public OcrDocumentRepository(DatabaseOptions options)
    {
        _options = options;
    }

    public IReadOnlyList<LocalOcrDocument> List()
    {
        return LocalDataStoreFile.Load(_options)
            .OcrDocuments
            .OrderByDescending(static document => document.CreatedAt)
            .ToList();
    }

    public LocalOcrDocument? Find(Guid id)
    {
        return LocalDataStoreFile.Load(_options)
            .OcrDocuments
            .FirstOrDefault(document => document.Id == id);
    }

    public OcrReport GetReport()
    {
        var documents = LocalDataStoreFile.Load(_options).OcrDocuments;
        return new OcrReport(
            documents.Count,
            documents.Count(static document => document.Status == LocalOcrStatus.Uploaded),
            documents.Count(static document => document.Status == LocalOcrStatus.Recognized),
            documents.Count(static document => document.Status == LocalOcrStatus.MappingRequired),
            documents.Count(static document => document.Status == LocalOcrStatus.Confirmed),
            documents.Count(static document => document.Status == LocalOcrStatus.ConvertedToReceipt),
            documents.Count(static document => document.Status == LocalOcrStatus.Failed),
            documents.Sum(static document => document.TotalAmount ?? 0));
    }

    public SaveOcrDocumentResult Save(LocalOcrDocument document)
    {
        var store = LocalDataStoreFile.Load(_options);
        var documentNumber = document.DocumentNumber.Trim().ToUpperInvariant();

        if (string.IsNullOrWhiteSpace(documentNumber))
        {
            return SaveOcrDocumentResult.ValidationError("單據編號為必填。");
        }

        var duplicatedNumber = store.OcrDocuments.Any(existing =>
            existing.Id != document.Id &&
            string.Equals(existing.DocumentNumber, documentNumber, StringComparison.OrdinalIgnoreCase));
        if (duplicatedNumber)
        {
            return SaveOcrDocumentResult.ValidationError("單據編號已存在，請改用其他編號。");
        }

        var existingDocument = store.OcrDocuments.FirstOrDefault(existing => existing.Id == document.Id);
        if (existingDocument is null)
        {
            document.Id = document.Id == Guid.Empty ? Guid.NewGuid() : document.Id;
            document.DocumentNumber = documentNumber;
            document.FileName = BlankToEmpty(document.FileName);
            document.SupplierName = BlankToNull(document.SupplierName);
            document.RawText = BlankToNull(document.RawText);
            document.RecognizedItems = BlankToNull(document.RecognizedItems);
            document.ReviewNote = BlankToNull(document.ReviewNote);
            document.CreatedAt = DateTime.UtcNow;
            store.OcrDocuments.Add(document);
        }
        else
        {
            existingDocument.DocumentNumber = documentNumber;
            existingDocument.FileName = BlankToEmpty(document.FileName);
            existingDocument.SupplierName = BlankToNull(document.SupplierName);
            existingDocument.DocumentDate = document.DocumentDate;
            existingDocument.Status = document.Status;
            existingDocument.TotalAmount = document.TotalAmount;
            existingDocument.RawText = BlankToNull(document.RawText);
            existingDocument.RecognizedItems = BlankToNull(document.RecognizedItems);
            existingDocument.ReviewNote = BlankToNull(document.ReviewNote);
            existingDocument.UpdatedAt = DateTime.UtcNow;
        }

        LocalDataStoreFile.Save(_options, store);
        return SaveOcrDocumentResult.Success();
    }

    public void Review(Guid id, bool approved)
    {
        var store = LocalDataStoreFile.Load(_options);
        var document = store.OcrDocuments.FirstOrDefault(existing => existing.Id == id);
        if (document is null)
        {
            return;
        }

        document.Status = approved ? LocalOcrStatus.Confirmed : LocalOcrStatus.MappingRequired;
        document.ReviewedAt = DateTime.UtcNow;
        document.UpdatedAt = DateTime.UtcNow;
        LocalDataStoreFile.Save(_options, store);
    }

    public void ConvertToReceipt(Guid id)
    {
        var store = LocalDataStoreFile.Load(_options);
        var document = store.OcrDocuments.FirstOrDefault(existing => existing.Id == id);
        if (document is null)
        {
            return;
        }

        document.Status = LocalOcrStatus.ConvertedToReceipt;
        document.UpdatedAt = DateTime.UtcNow;
        LocalDataStoreFile.Save(_options, store);
    }

    public static string GetStatusName(LocalOcrStatus status)
    {
        return status switch
        {
            LocalOcrStatus.Uploaded => "已上傳",
            LocalOcrStatus.Recognized => "已辨識",
            LocalOcrStatus.MappingRequired => "待對應",
            LocalOcrStatus.Confirmed => "已確認",
            LocalOcrStatus.ConvertedToReceipt => "已轉進貨",
            LocalOcrStatus.Failed => "失敗",
            _ => status.ToString()
        };
    }

    private static string BlankToEmpty(string? value)
    {
        return string.IsNullOrWhiteSpace(value) ? string.Empty : value.Trim();
    }

    private static string? BlankToNull(string? value)
    {
        return string.IsNullOrWhiteSpace(value) ? null : value.Trim();
    }
}

public sealed record OcrReport(
    int TotalCount,
    int UploadedCount,
    int RecognizedCount,
    int MappingRequiredCount,
    int ConfirmedCount,
    int ConvertedToReceiptCount,
    int FailedCount,
    decimal TotalAmount);

public sealed record SaveOcrDocumentResult(bool IsSuccess, string? ErrorMessage)
{
    public static SaveOcrDocumentResult Success() => new(true, null);
    public static SaveOcrDocumentResult ValidationError(string message) => new(false, message);
}