using Core.Entities;
using Core.Models;
using System.Text.Json;

namespace Core.Validation;

/// <summary>
/// Configuration for validation thresholds and rules
/// </summary>
public class ValidationConfiguration
{
    // Event count thresholds
    /// <summary>
    /// Minimum recommended number of events per student (Warning if below)
    /// </summary>
    public int MinRecommendedEvents { get; set; } = 2;

    /// <summary>
    /// Maximum recommended number of events per student (Warning if above)
    /// </summary>
    public int MaxRecommendedEvents { get; set; } = 4;

    /// <summary>
    /// Minimum critical number of events per student (Error if below)
    /// </summary>
    public int MinCriticalEvents { get; set; } = 1;

    /// <summary>
    /// Maximum critical number of events per student (Error if above)
    /// </summary>
    public int MaxCriticalEvents { get; set; } = 6;

    /// <summary>
    /// Maximum recommended number of regional events per student (Warning if above)
    /// </summary>
    public int MaxRegionalEvents { get; set; } = 3;

    // Required event types
    /// <summary>
    /// Whether to require students to have at least one regional event
    /// </summary>
    public bool RequireRegionalEvent { get; set; } = true;

    /// <summary>
    /// Whether to require students to have at least one on-site activity
    /// </summary>
    public bool RequireOnSiteActivity { get; set; } = true;

    /// <summary>
    /// Whether to require students to have at least one individual event
    /// </summary>
    public bool RequireIndividualEvent { get; set; } = false;

    /// <summary>
    /// Whether to require team-based events to have an assigned captain
    /// </summary>
    public bool RequireTeamCaptain { get; set; } = true;

    // Severity levels for each rule type
    /// <summary>
    /// Severity level for "No Regional Event" warnings
    /// </summary>
    public ValidationSeverity NoRegionalEventSeverity { get; set; } = ValidationSeverity.Warning;

    /// <summary>
    /// Severity level for "No On-Site Activity" warnings
    /// </summary>
    public ValidationSeverity NoOnSiteActivitySeverity { get; set; } = ValidationSeverity.Warning;

    /// <summary>
    /// Severity level for "No Individual Event" warnings
    /// </summary>
    public ValidationSeverity NoIndividualEventSeverity { get; set; } = ValidationSeverity.Warning;

    /// <summary>
    /// Severity level for team size warnings
    /// </summary>
    public ValidationSeverity TeamSizeSeverity { get; set; } = ValidationSeverity.Warning;

    /// <summary>
    /// Severity level for event count warnings
    /// </summary>
    public ValidationSeverity EventCountSeverity { get; set; } = ValidationSeverity.Warning;

    /// <summary>
    /// Severity level for missing captain warnings
    /// </summary>
    public ValidationSeverity MissingCaptainSeverity { get; set; } = ValidationSeverity.Warning;

    /// <summary>
    /// Severity level for too many regional events warnings
    /// </summary>
    public ValidationSeverity TooManyRegionalEventsSeverity { get; set; } = ValidationSeverity.Warning;

    /// <summary>
    /// Default configuration matching current app behavior
    /// </summary>
    public static ValidationConfiguration Default => new()
    {
        RequireRegionalEvent = true,
        RequireOnSiteActivity = true,
        RequireIndividualEvent = false,
        MinRecommendedEvents = 2,
        MaxRecommendedEvents = 4,
        MinCriticalEvents = 1,
        MaxCriticalEvents = 6,
        MaxRegionalEvents = 3,
        RequireTeamCaptain = true,
        NoRegionalEventSeverity = ValidationSeverity.Warning,
        NoOnSiteActivitySeverity = ValidationSeverity.Warning,
        NoIndividualEventSeverity = ValidationSeverity.Warning,
        TeamSizeSeverity = ValidationSeverity.Warning,
        EventCountSeverity = ValidationSeverity.Warning,
        MissingCaptainSeverity = ValidationSeverity.Warning,
        TooManyRegionalEventsSeverity = ValidationSeverity.Warning
    };

    /// <summary>
    /// Create validation configuration from assignment parameters
    /// </summary>
    /// <param name="parameters">Assignment parameters to convert</param>
    /// <returns>Validation configuration matching the assignment parameters</returns>
    public static ValidationConfiguration FromAssignmentParameters(AssignmentParameters parameters)
    {
        return new ValidationConfiguration
        {
            RequireRegionalEvent = parameters.RequireRegional,
            RequireOnSiteActivity = parameters.RequireOnSite,
            MinRecommendedEvents = parameters.EventsLowerBound,
            MaxRecommendedEvents = parameters.EventsUpperBound,
            MinCriticalEvents = 1,
            MaxCriticalEvents = 6,
            RequireTeamCaptain = true,
            NoRegionalEventSeverity = ValidationSeverity.Warning,
            NoOnSiteActivitySeverity = ValidationSeverity.Warning,
            NoIndividualEventSeverity = ValidationSeverity.Warning,
            TeamSizeSeverity = ValidationSeverity.Warning,
            EventCountSeverity = ValidationSeverity.Warning,
            MissingCaptainSeverity = ValidationSeverity.Warning
        };
    }

    /// <summary>
    /// Deserialize validation configuration from JSON string
    /// </summary>
    /// <param name="json">JSON string containing configuration</param>
    /// <returns>ValidationConfiguration instance or Default if deserialization fails</returns>
    public static ValidationConfiguration FromJson(string json)
    {
        try
        {
            var options = new JsonSerializerOptions
            {
                PropertyNameCaseInsensitive = true,
                Converters = { new System.Text.Json.Serialization.JsonStringEnumConverter() }
            };
            return JsonSerializer.Deserialize<ValidationConfiguration>(json, options) ?? Default;
        }
        catch
        {
            return Default;
        }
    }

    /// <summary>
    /// Load validation configuration from a JSON file
    /// </summary>
    /// <param name="path">Path to the JSON configuration file</param>
    /// <returns>ValidationConfiguration instance or Default if file doesn't exist or loading fails</returns>
    public static async Task<ValidationConfiguration> LoadFromFileAsync(string path)
    {
        try
        {
            if (!File.Exists(path))
                return Default;

            var json = await File.ReadAllTextAsync(path);
            return FromJson(json);
        }
        catch
        {
            return Default;
        }
    }

    /// <summary>
    /// Save this validation configuration to a JSON file
    /// </summary>
    /// <param name="path">Path where the JSON file should be saved</param>
    public async Task SaveToFileAsync(string path)
    {
        var options = new JsonSerializerOptions
        {
            WriteIndented = true,
            Converters = { new System.Text.Json.Serialization.JsonStringEnumConverter() }
        };
        var json = JsonSerializer.Serialize(this, options);
        await File.WriteAllTextAsync(path, json);
    }
}