using System.Text.Json;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using TaskTracker.Core.Entities;
using TaskTracker.Core.Enums;
using TaskTracker.Core.Interfaces;

namespace TaskTracker.Api.Pages;

[IgnoreAntiforgeryToken]
public class AnalyticsModel : PageModel
{
    private readonly ITaskRepository _taskRepo;
    private readonly IContextEventRepository _contextRepo;
    private readonly IAppMappingRepository _mappingRepo;

    public AnalyticsModel(
        ITaskRepository taskRepo,
        IContextEventRepository contextRepo,
        IAppMappingRepository mappingRepo)
    {
        _taskRepo = taskRepo;
        _contextRepo = contextRepo;
        _mappingRepo = mappingRepo;
    }

    public int Minutes { get; set; } = 1440;
    public int? TaskId { get; set; }
    public List<WorkTask> Tasks { get; set; } = [];

    // Stat cards
    public int OpenTaskCount { get; set; }
    public string ActiveTimeDisplay { get; set; } = "--";
    public string TopCategory { get; set; } = "\u2014";

    // Chart data (serialized as JSON for Chart.js)
    public string TimelineChartJson { get; set; } = "[]";
    public string CategoryChartJson { get; set; } = "[]";

    // Activity feed
    public List<ContextEvent> ActivityItems { get; set; } = [];
    public int TotalActivityCount { get; set; }

    public static readonly Dictionary<string, string> CategoryColors = new()
    {
        ["Development"] = "#6366f1",
        ["Research"] = "#06b6d4",
        ["Communication"] = "#8b5cf6",
        ["DevOps"] = "#f97316",
        ["Documentation"] = "#14b8a6",
        ["Design"] = "#ec4899",
        ["Testing"] = "#3b82f6",
        ["General"] = "#64748b",
        ["Email"] = "#f59e0b",
        ["Engineering"] = "#6366f1",
        ["LaserCutting"] = "#ef4444",
        ["Unknown"] = "#475569",
    };

    public async Task<IActionResult> OnGetAsync(int minutes = 1440, int? taskId = null)
    {
        Minutes = minutes;
        TaskId = taskId;

        // Load all tasks
        Tasks = await _taskRepo.GetAllAsync(includeSubTasks: false);

        // Stat cards
        OpenTaskCount = Tasks.Count(t =>
            t.Status != WorkTaskStatus.Completed && t.Status != WorkTaskStatus.Abandoned);

        // Active time: sum elapsed across all tasks with StartedAt
        var totalMinutes = 0.0;
        foreach (var task in Tasks.Where(t => t.StartedAt.HasValue))
        {
            var start = task.StartedAt!.Value;
            var end = task.CompletedAt ?? (task.Status == WorkTaskStatus.Active ? DateTime.UtcNow : start);
            totalMinutes += (end - start).TotalMinutes;
        }

        if (totalMinutes >= 60)
            ActiveTimeDisplay = $"{(int)(totalMinutes / 60)}h {(int)(totalMinutes % 60)}m";
        else if (totalMinutes >= 1)
            ActiveTimeDisplay = $"{(int)totalMinutes}m";

        // Top category
        var topCat = Tasks
            .Where(t => !string.IsNullOrEmpty(t.Category))
            .GroupBy(t => t.Category)
            .OrderByDescending(g => g.Count())
            .FirstOrDefault();
        if (topCat != null)
            TopCategory = topCat.Key!;

        // Context events for the time range
        var events = await _contextRepo.GetRecentAsync(minutes);
        if (taskId.HasValue)
            events = events.Where(e => e.WorkTaskId == taskId.Value).ToList();

        // Mappings
        var mappings = await _mappingRepo.GetAllAsync();

        // Timeline chart data: bucket by hour
        var timelineData = events
            .GroupBy(e => e.Timestamp.ToLocalTime().Hour)
            .OrderBy(g => g.Key)
            .Select(g =>
            {
                // Determine dominant category for this hour
                var categoryCounts = g
                    .Select(e => ResolveCategory(e, mappings))
                    .GroupBy(c => c)
                    .OrderByDescending(cg => cg.Count())
                    .First();

                var category = categoryCounts.Key;
                var color = GetCategoryColor(category);
                var hour = g.Key;
                var label = hour == 0 ? "12 AM"
                    : hour < 12 ? $"{hour} AM"
                    : hour == 12 ? "12 PM"
                    : $"{hour - 12} PM";

                return new { hour = label, count = g.Count(), category, color };
            })
            .ToList();

        TimelineChartJson = JsonSerializer.Serialize(timelineData,
            new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase });

        // Category chart data
        var categoryData = events
            .Select(e => ResolveCategory(e, mappings))
            .GroupBy(c => c)
            .OrderByDescending(g => g.Count())
            .Select(g => new
            {
                category = g.Key,
                count = g.Count(),
                color = GetCategoryColor(g.Key)
            })
            .ToList();

        CategoryChartJson = JsonSerializer.Serialize(categoryData,
            new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase });

        // Activity feed: most recent 20
        var orderedEvents = events.OrderByDescending(e => e.Timestamp).ToList();
        TotalActivityCount = orderedEvents.Count;
        ActivityItems = orderedEvents.Take(20).ToList();

        return Page();
    }

    public async Task<IActionResult> OnGetActivityFeedAsync(int minutes = 1440, int? taskId = null, int offset = 0)
    {
        var events = await _contextRepo.GetRecentAsync(minutes);
        if (taskId.HasValue)
            events = events.Where(e => e.WorkTaskId == taskId.Value).ToList();

        var items = events
            .OrderByDescending(e => e.Timestamp)
            .Skip(offset)
            .Take(20)
            .ToList();

        TotalActivityCount = events.Count;
        ActivityItems = items;

        return Partial("Partials/_ActivityFeedItems", this);
    }

    private static string ResolveCategory(ContextEvent e, List<AppMapping> mappings)
    {
        foreach (var m in mappings)
        {
            bool match = m.MatchType switch
            {
                "ProcessName" => e.AppName.Contains(m.Pattern, StringComparison.OrdinalIgnoreCase),
                "TitleContains" => e.WindowTitle.Contains(m.Pattern, StringComparison.OrdinalIgnoreCase),
                "UrlContains" => e.Url?.Contains(m.Pattern, StringComparison.OrdinalIgnoreCase) == true,
                _ => false
            };
            if (match) return m.Category;
        }
        return "Unknown";
    }

    private static string GetCategoryColor(string? category)
    {
        if (string.IsNullOrEmpty(category)) return CategoryColors["Unknown"];
        return CategoryColors.TryGetValue(category, out var color) ? color : CategoryColors["Unknown"];
    }

    public static string FormatRelativeTime(DateTime dt)
    {
        var diff = DateTime.UtcNow - dt;
        if (diff.TotalMinutes < 1) return "just now";
        if (diff.TotalMinutes < 60) return $"{(int)diff.TotalMinutes}m ago";
        if (diff.TotalHours < 24) return $"{(int)diff.TotalHours}h ago";
        if (diff.TotalDays < 2) return "yesterday";
        if (diff.TotalDays < 7) return $"{(int)diff.TotalDays}d ago";
        if (diff.TotalDays < 30) return $"{(int)(diff.TotalDays / 7)}w ago";
        return dt.ToLocalTime().ToString("MMM d, yyyy");
    }
}