using System.Globalization;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;
using PlotLine.Services;

namespace PlotLine.Controllers;

[Authorize]
public sealed class StoryCalendarController(IStoryCalendarService calendar, ILogger<StoryCalendarController> logger) : Controller
{
    public async Task<IActionResult> Index(int projectId, int? bookId, string? month, string? date)
    {
        if (projectId == 0)
        {
            return BadRequest("ProjectID is required.");
        }

        var selectedMonth = ParseMonth(month);
        var selectedDate = ParseDate(date);
        var model = await calendar.GetAsync(projectId, bookId, selectedMonth, selectedDate);
        if (model is null)
        {
            return NotFound();
        }

        return IsAjaxRequest()
            ? PartialView("_StoryCalendarSurface", model)
            : View(model);
    }

    [HttpGet]
    public async Task<IActionResult> DayDetails(int projectId, int? bookId, string? date)
    {
        if (projectId == 0)
        {
            return BadRequest("ProjectID is required.");
        }

        var selectedDate = ParseDate(date);
        if (!selectedDate.HasValue)
        {
            return BadRequest("Date is required.");
        }

        try
        {
            var model = await calendar.GetAsync(projectId, bookId, FirstOfMonth(selectedDate.Value), selectedDate);
            return model is null ? NotFound() : PartialView("_StoryCalendarDayDetails", model.DayDetails);
        }
        catch (Exception ex)
        {
            logger.LogError(ex, "Failed to load Story Calendar day details for project {ProjectID} and date {StoryDate}.", projectId, date);
            return StatusCode(StatusCodes.Status500InternalServerError, "The selected story date could not be loaded.");
        }
    }

    [HttpPost]
    [ValidateAntiForgeryToken]
    public IActionResult ApplyFilters(int projectId, int? bookId, string? month)
    {
        return RedirectToAction(nameof(Index), new
        {
            projectId,
            bookId,
            month
        });
    }

    private static DateOnly? ParseMonth(string? value)
    {
        if (string.IsNullOrWhiteSpace(value))
        {
            return null;
        }

        return DateOnly.TryParseExact(
            $"{value.Trim()}-01",
            "yyyy-MM-dd",
            CultureInfo.InvariantCulture,
            DateTimeStyles.None,
            out var parsed)
            ? new DateOnly(parsed.Year, parsed.Month, 1)
            : null;
    }

    private static DateOnly? ParseDate(string? value)
    {
        if (string.IsNullOrWhiteSpace(value))
        {
            return null;
        }

        return DateOnly.TryParseExact(
            value.Trim(),
            "yyyy-MM-dd",
            CultureInfo.InvariantCulture,
            DateTimeStyles.None,
            out var parsed)
            ? parsed
            : null;
    }

    private static DateOnly FirstOfMonth(DateOnly date)
        => new(date.Year, date.Month, 1);

    private bool IsAjaxRequest()
        => string.Equals(Request.Headers["X-Requested-With"], "XMLHttpRequest", StringComparison.OrdinalIgnoreCase);
}