using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Text.Json;
using System.Threading;
using System.Threading.Tasks;
using FinlyticCore.Dtos.Yahoo;
using FinlyticCore.Services.Yahoo;
using FinlyticFundamentals.Entities;
using Microsoft.Extensions.Logging;

namespace FinlyticFundamentals.Services;

public interface IYahooFinanceScraper
{
    /// <summary>
    /// Resolves ticker from ISIN.
    /// </summary>
    Task<string?> ResolveTickerFromIsinAsync(string isin, CancellationToken cancellationToken = default);

    /// <summary>
    /// Resolves all tickers from ISIN.
    /// </summary>
    Task<List<string>> ResolveAllTickersFromIsinAsync(string isin, CancellationToken cancellationToken = default);

    /// <summary>
    /// Scrapes fundamentals.
    /// </summary>
    Task<ScrapedFundamentalsData?> ScrapeFundamentalsAsync(string isin, string ticker,
        CancellationToken cancellationToken = default);
}

public record ScrapedFundamentalsData(
    AssetFundamentalsEntity Fundamentals,
    TickerFundamentalsEntity TickerData,
    List<CompanyExecutiveEntity> Executives,
    List<FinancialStatementEntity> Statements,
    List<ForwardEstimateEntity> Estimates
);

public class YahooFinanceScraper : IYahooFinanceScraper
{
    private readonly HttpClient _httpClient;
    private readonly YahooFinanceClient _yahooClient;
    private readonly ILogger<YahooFinanceScraper> _logger;

    public YahooFinanceScraper(HttpClient httpClient, YahooFinanceClient yahooClient,
        ILogger<YahooFinanceScraper> logger)
    {
        _httpClient = httpClient;
        _yahooClient = yahooClient;
        _logger = logger;
    }

    /// <inheritdoc />
    public async Task<string?> ResolveTickerFromIsinAsync(string isin, CancellationToken cancellationToken = default)
    {
        var tickers = await ResolveAllTickersFromIsinAsync(isin, cancellationToken);
        return tickers.FirstOrDefault();
    }

    /// <inheritdoc />
    public async Task<List<string>> ResolveAllTickersFromIsinAsync(string isin,
        CancellationToken cancellationToken = default)
    {
        if (string.IsNullOrWhiteSpace(isin)) return new();

        var symbols = new List<(string symbol, int priority)>();

        var primary = await _yahooClient.SearchAsync(isin, quotesCount: 20, cancellationToken: cancellationToken);
        var quotes = primary?.Quotes ?? new();

        foreach (var q in quotes.Where(q => !string.IsNullOrEmpty(q.Symbol)))
        {
            symbols.Add((q.Symbol, GetExchangePriority(q.Symbol, isin)));
        }

        if (quotes.Count == 0) return [];

        // 2. Namenssuche für deutsche/andere Handelsplätze
        var companyName = quotes[0].LongName!;

        var secondary =
            await _yahooClient.SearchAsync(companyName, quotesCount: 20, cancellationToken: cancellationToken);

        foreach (var q in secondary?.Quotes ?? new())
        {
            if (!string.IsNullOrEmpty(q.Symbol) &&
                !symbols.Any(s => s.symbol.Equals(q.Symbol, StringComparison.OrdinalIgnoreCase)))
            {
                symbols.Add((q.Symbol, GetExchangePriority(q.Symbol, isin)));
            }
        }


        // 3. Sortieren und zurückgeben
        return symbols
            .OrderBy(s => s.priority)
            .Select(s => s.symbol)
            .Distinct(StringComparer.OrdinalIgnoreCase)
            .Take(20)
            .ToList();
    }

    private int GetExchangePriority(string symbol, string isin)
    {
        if (!string.IsNullOrEmpty(isin) && isin.StartsWith("US", StringComparison.OrdinalIgnoreCase))
        {
            if (!symbol.Contains('.')) return 1;
            if (symbol.EndsWith(".DE", StringComparison.OrdinalIgnoreCase)) return 2;
            if (symbol.EndsWith(".F", StringComparison.OrdinalIgnoreCase) ||
                symbol.EndsWith(".SG", StringComparison.OrdinalIgnoreCase)) return 3;
            return 4;
        }

        if (symbol.EndsWith(".DE", StringComparison.OrdinalIgnoreCase))
        {
            return 1; // XETRA
        }
        else if (symbol.EndsWith(".F", StringComparison.OrdinalIgnoreCase))
        {
            return 2; // Frankfurt
        }
        else if (symbol.EndsWith(".TG", StringComparison.OrdinalIgnoreCase))
        {
            return 3; // Gettex
        }
        else if (symbol.EndsWith(".MU", StringComparison.OrdinalIgnoreCase) ||
                 symbol.EndsWith(".SG", StringComparison.OrdinalIgnoreCase) ||
                 symbol.EndsWith(".BE", StringComparison.OrdinalIgnoreCase) ||
                 symbol.EndsWith(".DU", StringComparison.OrdinalIgnoreCase) ||
                 symbol.EndsWith(".HM", StringComparison.OrdinalIgnoreCase))
        {
            return 4; // Other German regional exchanges
        }
        else if (symbol.Contains('.') && !symbol.EndsWith(".OB", StringComparison.OrdinalIgnoreCase) &&
                 !symbol.EndsWith(".PK", StringComparison.OrdinalIgnoreCase))
        {
            return 5; // Domestic/home non-US exchanges
        }
        else
        {
            return 6; // Other
        }
    }

    /// <inheritdoc />
    public async Task<ScrapedFundamentalsData?> ScrapeFundamentalsAsync(string isin, string ticker,
        CancellationToken cancellationToken = default)
    {
        _logger.LogInformation(
            "[{Channel}] Fetching fundamental data for Ticker {Ticker} (ISIN: {Isin}) using YahooFinanceClient...",
            "FundamentalsChannel", ticker, isin);

        try
        {
            var summaryResponse = await _yahooClient.GetFullQuoteSummaryAsync(ticker, cancellationToken);
            if (summaryResponse?.QuoteSummary?.Result == null || summaryResponse.QuoteSummary.Result.Count == 0)
            {
                _logger.LogWarning("[{Channel}] YahooFinanceClient returned no result for ticker {Ticker}",
                    "FundamentalsChannel", ticker);
                return null;
            }

            var root = summaryResponse.QuoteSummary.Result[0];

            var assetProfile = root.AssetProfile;
            var financialData = root.FinancialData;
            var defaultKeyStatistics = root.DefaultKeyStatistics;
            var summaryDetail = root.SummaryDetail;
            var calendarEvents = root.CalendarEvents;

            // Instantiate entities
            var fundamentals = new AssetFundamentalsEntity
            {
                Isin = isin,
                PrimaryTicker = ticker,
                LastUpdatedAt = DateTime.UtcNow,
                LastStaticUpdatedAt = DateTime.UtcNow
            };

            var tickerData = new TickerFundamentalsEntity
            {
                Ticker = ticker,
                Isin = isin,
                LastUpdatedAt = DateTime.UtcNow
            };

            // 1. Static Profile Data
            if (assetProfile != null)
            {
                fundamentals.BusinessSummary = assetProfile.LongBusinessSummary;
                fundamentals.Sector = assetProfile.Sector;
                fundamentals.Industry = assetProfile.Industry;
                fundamentals.Country = assetProfile.Country;
                fundamentals.Employees = assetProfile.FullTimeEmployees;
            }

            // Company Name
            fundamentals.CompanyName = ticker;

            // 2. Exchange & Trading Currency for Ticker
            if (financialData != null && !string.IsNullOrWhiteSpace(financialData.FinancialCurrency))
            {
                tickerData.TradingCurrency = financialData.FinancialCurrency;
            }

            if (summaryDetail != null && !string.IsNullOrWhiteSpace(summaryDetail.Currency))
            {
                tickerData.TradingCurrency = summaryDetail.Currency;
            }

            // 3. Dynamic Price & Valuation Data
            if (financialData != null)
            {
                tickerData.CurrentPrice = financialData.CurrentPrice?.DecimalValue ?? 0;
                tickerData.GrossMargin = financialData.GrossMargins?.DecimalValue;
                tickerData.OperatingMargin = financialData.OperatingMargins?.DecimalValue;
                tickerData.NetProfitMargin = financialData.ProfitMargins?.DecimalValue;
                tickerData.ReturnOnEquity = financialData.ReturnOnEquity?.DecimalValue;
                tickerData.ReturnOnAssets = financialData.ReturnOnAssets?.DecimalValue;
                tickerData.CurrentRatio = financialData.CurrentRatio?.DecimalValue;
                tickerData.QuickRatio = financialData.QuickRatio?.DecimalValue;
                tickerData.DebtToEquity = financialData.DebtToEquity?.DecimalValue;

                // Targets on Company Level
                fundamentals.PriceTargetLow = financialData.TargetLowPrice?.DecimalValue;
                fundamentals.PriceTargetHigh = financialData.TargetHighPrice?.DecimalValue;
                fundamentals.PriceTargetMedian = financialData.TargetMedianPrice?.DecimalValue;
                fundamentals.PriceTargetMean = financialData.TargetMeanPrice?.DecimalValue;
            }

            if (summaryDetail != null)
            {
                if (tickerData.CurrentPrice == 0)
                {
                    tickerData.CurrentPrice = summaryDetail.Open?.DecimalValue ??
                                              summaryDetail.PreviousClose?.DecimalValue ?? 0;
                }

                tickerData.FiftyTwoWeekHigh = summaryDetail.FiftyTwoWeekHigh?.DecimalValue ?? 0;
                tickerData.FiftyTwoWeekLow = summaryDetail.FiftyTwoWeekLow?.DecimalValue ?? 0;
            }

            var mCap = defaultKeyStatistics?.SharesOutstanding?.DecimalValue;
            mCap ??= summaryDetail?.MarketCap?.DecimalValue;
            tickerData.MarketCapitalization = mCap ?? 0;

            var ev = defaultKeyStatistics?.EnterpriseValue?.DecimalValue;
            tickerData.EnterpriseValue = ev ?? 0;

            tickerData.PeRatioTrailing = defaultKeyStatistics?.TrailingEps?.DecimalValue ??
                                         summaryDetail?.TrailingPE?.DecimalValue;
            tickerData.PeRatioForward =
                defaultKeyStatistics?.ForwardPE?.DecimalValue ?? summaryDetail?.ForwardPE?.DecimalValue;

            if (defaultKeyStatistics != null)
            {
                tickerData.PegRatio = defaultKeyStatistics.PegRatio?.DecimalValue;
                tickerData.PbRatio = defaultKeyStatistics.PriceToBook?.DecimalValue;
                fundamentals.ShortRatio = defaultKeyStatistics.ShortRatio?.DecimalValue;
                fundamentals.ShortPercentOfFloat = defaultKeyStatistics.ShortPercentOfFloat?.DecimalValue;
                fundamentals.PercentHeldByInstitutions = defaultKeyStatistics.HeldPercentInstitutions?.DecimalValue;
                fundamentals.PercentHeldByInsiders = defaultKeyStatistics.HeldPercentInsiders?.DecimalValue;
            }

            tickerData.PsRatio = defaultKeyStatistics?.PriceToSalesTrailing12Months?.DecimalValue ??
                                 summaryDetail?.PriceToSalesTrailing12Months?.DecimalValue;
            tickerData.EvToEbitda = defaultKeyStatistics?.EnterpriseToEbitda?.DecimalValue;
            tickerData.EvToRevenue = defaultKeyStatistics?.EnterpriseToRevenue?.DecimalValue;

            tickerData.DividendYield = summaryDetail?.DividendYield?.DecimalValue;
            tickerData.PayoutRatio = summaryDetail?.PayoutRatio?.DecimalValue;

            if (financialData != null)
            {
                if (!string.IsNullOrWhiteSpace(financialData.RecommendationKey) &&
                    !financialData.RecommendationKey.Equals("none", StringComparison.OrdinalIgnoreCase))
                {
                    fundamentals.ConsensusRating = financialData.RecommendationKey;
                }
                else if (financialData.RecommendationMean != null && financialData.RecommendationMean.Raw.HasValue)
                {
                    double mean = financialData.RecommendationMean.Raw.Value;
                    fundamentals.ConsensusRating = mean <= 1.8
                        ? "strong_buy"
                        : (mean <= 2.5 ? "buy" : (mean <= 3.5 ? "hold" : (mean <= 4.2 ? "sell" : "strong_sell")));
                }
            }

            // 4. Calendar Events Data
            if (calendarEvents != null)
            {
                if (calendarEvents.ExDividendDate?.Raw.HasValue == true)
                {
                    long seconds = (long)calendarEvents.ExDividendDate.Raw.Value;
                    if (seconds > 0)
                        fundamentals.ExDividendDate = DateTimeOffset.FromUnixTimeSeconds(seconds).UtcDateTime;
                }

                if (calendarEvents.Earnings?.EarningsDate != null && calendarEvents.Earnings.EarningsDate.Count > 0)
                {
                    var firstDate = calendarEvents.Earnings.EarningsDate[0];
                    if (firstDate.Raw.HasValue && firstDate.Raw.Value > 0)
                    {
                        fundamentals.NextEarningsDate =
                            DateTimeOffset.FromUnixTimeSeconds((long)firstDate.Raw.Value).UtcDateTime;
                    }
                }
            }

            if (!fundamentals.ExDividendDate.HasValue && summaryDetail?.ExDividendDate?.Raw.HasValue == true)
            {
                long seconds = (long)summaryDetail.ExDividendDate.Raw.Value;
                if (seconds > 0) fundamentals.ExDividendDate = DateTimeOffset.FromUnixTimeSeconds(seconds).UtcDateTime;
            }

            tickerData.ExDividendDate = fundamentals.ExDividendDate;

            // 5. Executives List
            var executives = new List<CompanyExecutiveEntity>();
            if (assetProfile?.CompanyOfficers != null)
            {
                foreach (var officer in assetProfile.CompanyOfficers)
                {
                    var exec = new CompanyExecutiveEntity
                    {
                        Isin = isin,
                        Name = !string.IsNullOrWhiteSpace(officer.Name) ? officer.Name : "Unknown",
                        Title = !string.IsNullOrWhiteSpace(officer.Title) ? officer.Title : "Officer",
                        Age = officer.Age,
                        Compensation = officer.TotalPay?.DecimalValue
                    };
                    executives.Add(exec);
                }
            }

            // 6. Financial Statements
            var statements = new List<FinancialStatementEntity>();

            // A. Annual Statements
            if (root.IncomeStatementHistory?.IncomeStatementHistory != null)
            {
                foreach (var item in root.IncomeStatementHistory.IncomeStatementHistory)
                {
                    MapIncomeStatement(item, isin, "Annual", statements);
                }
            }

            if (root.BalanceSheetHistory?.BalanceSheetStatements != null)
            {
                foreach (var item in root.BalanceSheetHistory.BalanceSheetStatements)
                {
                    MapBalanceSheet(item, isin, "Annual", statements);
                }
            }

            if (root.CashflowStatementHistory?.CashflowStatements != null)
            {
                foreach (var item in root.CashflowStatementHistory.CashflowStatements)
                {
                    MapCashflowStatement(item, isin, "Annual", statements);
                }
            }

            // B. Quarterly Statements
            if (root.IncomeStatementHistoryQuarterly?.IncomeStatementHistory != null)
            {
                foreach (var item in root.IncomeStatementHistoryQuarterly.IncomeStatementHistory)
                {
                    MapIncomeStatement(item, isin, "Quarterly", statements);
                }
            }

            if (root.BalanceSheetHistoryQuarterly?.BalanceSheetStatements != null)
            {
                foreach (var item in root.BalanceSheetHistoryQuarterly.BalanceSheetStatements)
                {
                    MapBalanceSheet(item, isin, "Quarterly", statements);
                }
            }

            if (root.CashflowStatementHistoryQuarterly?.CashflowStatements != null)
            {
                foreach (var item in root.CashflowStatementHistoryQuarterly.CashflowStatements)
                {
                    MapCashflowStatement(item, isin, "Quarterly", statements);
                }
            }

            // 7. Forward Estimates
            var estimates = new List<ForwardEstimateEntity>();

            return new ScrapedFundamentalsData(fundamentals, tickerData, executives, statements, estimates);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "[{Channel}] Failed to scrape fundamentals for ISIN {Isin} (Ticker: {Ticker})",
                "FundamentalsChannel", isin, ticker);
            return null;
        }
    }

    private static void MapIncomeStatement(YahooIncomeStatementDto item, string isin, string periodType,
        List<FinancialStatementEntity> statements)
    {
        if (item.EndDate?.Raw.HasValue != true) return;
        var endDate = DateTimeOffset.FromUnixTimeSeconds((long)item.EndDate.Raw.Value).UtcDateTime.Date;

        var statement = GetOrCreateStatement(statements, isin, periodType, endDate);

        if (item.TotalRevenue?.Raw.HasValue == true) statement.TotalRevenue = item.TotalRevenue.DecimalValue;
        if (item.CostOfRevenue?.Raw.HasValue == true) statement.CostOfRevenue = item.CostOfRevenue.DecimalValue;
        if (item.GrossProfit?.Raw.HasValue == true) statement.GrossProfit = item.GrossProfit.DecimalValue;
        else if (statement.TotalRevenue.HasValue && statement.CostOfRevenue.HasValue)
            statement.GrossProfit = statement.TotalRevenue - statement.CostOfRevenue;

        if (item.TotalOperatingExpenses?.Raw.HasValue == true)
            statement.OperatingExpenses = item.TotalOperatingExpenses.DecimalValue;
        if (item.OperatingIncome?.Raw.HasValue == true) statement.OperatingIncome = item.OperatingIncome.DecimalValue;
        else if (statement.GrossProfit.HasValue && statement.OperatingExpenses.HasValue)
            statement.OperatingIncome = statement.GrossProfit - statement.OperatingExpenses;

        if (item.Ebit?.Raw.HasValue == true) statement.Ebitda = item.Ebit.DecimalValue;
        if (item.NetIncome?.Raw.HasValue == true) statement.NetIncome = item.NetIncome.DecimalValue;
    }

    private static void MapBalanceSheet(YahooBalanceSheetStatementDto item, string isin, string periodType,
        List<FinancialStatementEntity> statements)
    {
        if (item.EndDate?.Raw.HasValue != true) return;
        var endDate = DateTimeOffset.FromUnixTimeSeconds((long)item.EndDate.Raw.Value).UtcDateTime.Date;

        var statement = GetOrCreateStatement(statements, isin, periodType, endDate);

        if (item.Cash?.Raw.HasValue == true) statement.CashAndCashEquivalents = item.Cash.DecimalValue;
        if (item.NetReceivables?.Raw.HasValue == true) statement.AccountsReceivable = item.NetReceivables.DecimalValue;
        if (item.Inventory?.Raw.HasValue == true) statement.Inventory = item.Inventory.DecimalValue;
        if (item.TotalCurrentAssets?.Raw.HasValue == true)
            statement.TotalCurrentAssets = item.TotalCurrentAssets.DecimalValue;
        if (item.TotalCurrentLiabilities?.Raw.HasValue == true)
            statement.CurrentLiabilities = item.TotalCurrentLiabilities.DecimalValue;
        if (item.LongTermDebt?.Raw.HasValue == true) statement.LongTermDebt = item.LongTermDebt.DecimalValue;
        if (item.TotalLiab?.Raw.HasValue == true) statement.TotalLiabilities = item.TotalLiab.DecimalValue;
        if (item.TotalStockholderEquity?.Raw.HasValue == true)
            statement.TotalStockholdersEquity = item.TotalStockholderEquity.DecimalValue;
    }

    private static void MapCashflowStatement(YahooCashflowStatementDto item, string isin, string periodType,
        List<FinancialStatementEntity> statements)
    {
        if (item.EndDate?.Raw.HasValue != true) return;
        var endDate = DateTimeOffset.FromUnixTimeSeconds((long)item.EndDate.Raw.Value).UtcDateTime.Date;

        var statement = GetOrCreateStatement(statements, isin, periodType, endDate);

        if (item.TotalCashFromOperatingActivities?.Raw.HasValue == true)
            statement.OperatingCashFlow = item.TotalCashFromOperatingActivities.DecimalValue;
        if (item.TotalCashflowsFromInvestingActivities?.Raw.HasValue == true)
            statement.InvestingCashFlow = item.TotalCashflowsFromInvestingActivities.DecimalValue;
        if (item.CapitalExpenditures?.Raw.HasValue == true)
            statement.CapitalExpenditures = item.CapitalExpenditures.DecimalValue;
        if (item.TotalCashFromFinancingActivities?.Raw.HasValue == true)
            statement.FinancingCashFlow = item.TotalCashFromFinancingActivities.DecimalValue;

        if (statement.OperatingCashFlow.HasValue)
        {
            var capex = statement.CapitalExpenditures ?? 0m;
            statement.FreeCashFlow = statement.OperatingCashFlow.Value - Math.Abs(capex);
        }
    }

    private static FinancialStatementEntity GetOrCreateStatement(List<FinancialStatementEntity> statements, string isin,
        string periodType, DateTime endDate)
    {
        var existing = statements.FirstOrDefault(s => s.PeriodType == periodType && s.EndDate.Date == endDate.Date);
        if (existing == null)
        {
            existing = new FinancialStatementEntity
            {
                Isin = isin,
                PeriodType = periodType,
                EndDate = endDate.Date
            };
            statements.Add(existing);
        }

        return existing;
    }
}