using InnovEnergy.App.Backend.DataTypes;
using InnovEnergy.App.Backend.Relations;
namespace InnovEnergy.App.Backend.Database;


public static partial class Db 
{
    //In this file, we provide all the methods that can be used in order to retrieve information from the database (read)
    public static Folder? GetFolderById(Int64? id)
    {
        return Folders
              .FirstOrDefault(f => f.Id == id);
    }
        
    public static Installation? GetInstallationById(Int64? id)
    {
        return Installations
            .FirstOrDefault(i => i.Id == id);
    }
    
    public static UserAction? GetActionById(Int64? id)
    {
        return UserActions
            .FirstOrDefault(i => i.Id == id);
    }
    
    public static User? GetUserById(Int64? id)
    {
        return Users
            .FirstOrDefault(u => u.Id == id);
    }
    
    public static User? GetUserByEmail(String email)
    {
        return Users
              .FirstOrDefault(u => u.Email == email);
    }

    public static Session? GetSession(String token)
    {
        //This method is called in almost every controller function.
        //After logging in, the frontend receives a session object which contains a token. For all the future REST API calls, this token is used for session authentication.
        var session = Sessions
                     .FirstOrDefault(s => s.Token == token);

        if (session is null)
        {
            return null;
        }

        if (!session.Valid)
        {
            Delete(session);
            return null;
        }

        return session;
    }

    // ── Report Queries ────────────────────────────────────────────────

    public static List<WeeklyReportSummary> GetWeeklyReports(Int64 installationId)
        => WeeklyReports
            .Where(r => r.InstallationId == installationId)
            .OrderByDescending(r => r.PeriodStart)
            .ToList();

    public static List<WeeklyReportSummary> GetWeeklyReportsForMonth(Int64 installationId, Int32 year, Int32 month)
    {
        var monthStart = $"{year:D4}-{month:D2}-01";
        var monthEnd   = month == 12 ? $"{year + 1:D4}-01-01" : $"{year:D4}-{month + 1:D2}-01";
        return WeeklyReports
            .Where(r => r.InstallationId == installationId)
            .ToList()
            .Where(r => String.Compare(r.PeriodStart, monthStart, StringComparison.Ordinal) >= 0
                     && String.Compare(r.PeriodStart, monthEnd,   StringComparison.Ordinal) <  0)
            .ToList();
    }

    public static List<MonthlyReportSummary> GetMonthlyReports(Int64 installationId)
        => MonthlyReports
            .Where(r => r.InstallationId == installationId)
            .OrderByDescending(r => r.Year)
            .ThenByDescending(r => r.Month)
            .ToList();

    public static List<MonthlyReportSummary> GetMonthlyReportsForYear(Int64 installationId, Int32 year)
        => MonthlyReports
            .Where(r => r.InstallationId == installationId && r.Year == year)
            .ToList();

    public static List<YearlyReportSummary> GetYearlyReports(Int64 installationId)
        => YearlyReports
            .Where(r => r.InstallationId == installationId)
            .OrderByDescending(r => r.Year)
            .ToList();

    // ── DailyEnergyRecord Queries ──────────────────────────────────────

    /// <summary>
    /// Returns daily records for an installation within [from, to] inclusive, ordered by date.
    /// </summary>
    public static List<DailyEnergyRecord> GetDailyRecords(Int64 installationId, DateOnly from, DateOnly to)
    {
        var fromStr = from.ToString("yyyy-MM-dd");
        var toStr   = to.ToString("yyyy-MM-dd");
        return DailyRecords
            .Where(r => r.InstallationId == installationId)
            .ToList()
            .Where(r => String.Compare(r.Date, fromStr, StringComparison.Ordinal) >= 0
                     && String.Compare(r.Date, toStr,   StringComparison.Ordinal) <= 0)
            .OrderBy(r => r.Date)
            .ToList();
    }

    /// <summary>
    /// Returns true if a daily record already exists for this installation+date (idempotency check).
    /// </summary>
    public static Boolean DailyRecordExists(Int64 installationId, String date)
        => DailyRecords
            .Any(r => r.InstallationId == installationId && r.Date == date);

    // ── HourlyEnergyRecord Queries ─────────────────────────────────────

    /// <summary>
    /// Returns hourly records for an installation within [from, to] inclusive, ordered by date+hour.
    /// </summary>
    public static List<HourlyEnergyRecord> GetHourlyRecords(Int64 installationId, DateOnly from, DateOnly to)
    {
        var fromStr = from.ToString("yyyy-MM-dd");
        var toStr   = to.ToString("yyyy-MM-dd");
        return HourlyRecords
            .Where(r => r.InstallationId == installationId)
            .ToList()
            .Where(r => String.Compare(r.Date, fromStr, StringComparison.Ordinal) >= 0
                     && String.Compare(r.Date, toStr,   StringComparison.Ordinal) <= 0)
            .OrderBy(r => r.Date).ThenBy(r => r.Hour)
            .ToList();
    }

    /// <summary>
    /// Returns true if an hourly record already exists for this installation+dateHour (idempotency check).
    /// </summary>
    public static Boolean HourlyRecordExists(Int64 installationId, String dateHour)
        => HourlyRecords
            .Any(r => r.InstallationId == installationId && r.DateHour == dateHour);

    // ── AiInsightCache Queries ─────────────────────────────────────────

    /// <summary>
    /// Returns the cached AI insight text for (reportType, reportId, language), or null on miss.
    /// </summary>
    public static String? GetCachedInsight(String reportType, Int64 reportId, String language)
        => AiInsightCaches
            .FirstOrDefault(c => c.ReportType == reportType
                              && c.ReportId   == reportId
                              && c.Language   == language)
            ?.InsightText;

    // ── Ticket Queries ──────────────────────────────────────────────────

    public static Ticket? GetTicketById(Int64 id)
        => Tickets.FirstOrDefault(t => t.Id == id);

    public static List<Ticket> GetAllTickets()
        => Tickets.OrderByDescending(t => t.UpdatedAt).ToList();

    public static List<Ticket> GetTicketsForInstallation(Int64 installationId)
        => Tickets
            .Where(t => t.InstallationId == installationId)
            .OrderByDescending(t => t.CreatedAt)
            .ToList();

    public static List<TicketComment> GetCommentsForTicket(Int64 ticketId)
        => TicketComments
            .Where(c => c.TicketId == ticketId)
            .OrderBy(c => c.CreatedAt)
            .ToList();

    public static TicketAiDiagnosis? GetDiagnosisForTicket(Int64 ticketId)
        => TicketAiDiagnoses.FirstOrDefault(d => d.TicketId == ticketId);

    public static List<TicketTimelineEvent> GetTimelineForTicket(Int64 ticketId)
        => TicketTimelineEvents
            .Where(e => e.TicketId == ticketId)
            .OrderBy(e => e.CreatedAt)
            .ToList();
}