using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using PlotLine.Models;
using PlotLine.Services;
using PlotLine.ViewModels;

namespace PlotLine.Controllers;

[Authorize]
[Route("onboarding")]
public sealed class OnboardingController(IOnboardingService onboarding) : Controller
{
    [HttpGet("")]
    public async Task<IActionResult> Index()
    {
        var model = await onboarding.GetWizardAsync();
        return View(model);
    }

    [HttpGet("scan-review")]
    public async Task<IActionResult> ScanReview(Guid? previewId)
    {
        var model = await onboarding.GetScanReviewAsync(previewId);
        return model is null ? NotFound() : View(model);
    }

    [HttpPost("welcome")]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> Welcome()
    {
        await onboarding.MoveToNextStepAsync();
        return RedirectToAction(nameof(Index));
    }

    [HttpPost("writing-journey")]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> WritingJourney(WritingJourneyOnboardingForm form)
    {
        if (!ModelState.IsValid || string.IsNullOrWhiteSpace(form.WritingJourney))
        {
            var model = await onboarding.GetWizardAsync();
            model.CurrentStep = OnboardingSteps.WritingJourney;
            model.StepNumber = 2;
            return View(nameof(Index), model);
        }

        await onboarding.SaveWritingJourneyAsync(form.WritingJourney);
        return RedirectToAction(nameof(Index));
    }

    [HttpPost("writing-software")]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> WritingSoftware(WritingSoftwareOnboardingForm form)
    {
        if (!ModelState.IsValid || string.IsNullOrWhiteSpace(form.WritingSoftware))
        {
            var model = await onboarding.GetWizardAsync();
            model.CurrentStep = OnboardingSteps.WritingSoftware;
            model.StepNumber = 3;
            return View(nameof(Index), model);
        }

        await onboarding.SaveWritingSoftwareAsync(form.WritingSoftware);
        return RedirectToAction(nameof(Index));
    }

    [HttpPost("project")]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> Project(ProjectOnboardingForm form)
    {
        if (string.Equals(form.Mode, OnboardingSelectionModes.Create, StringComparison.Ordinal)
            && string.IsNullOrWhiteSpace(form.ProjectName))
        {
            ModelState.AddModelError(nameof(form.ProjectName), "Enter a project name.");
        }

        if (string.Equals(form.Mode, OnboardingSelectionModes.Select, StringComparison.Ordinal)
            && !form.SelectedProjectID.HasValue)
        {
            ModelState.AddModelError(nameof(form.SelectedProjectID), "Choose one of your active projects.");
        }

        if (!ModelState.IsValid)
        {
            var invalidModel = await onboarding.GetWizardAsync();
            invalidModel.CurrentStep = OnboardingSteps.Project;
            invalidModel.StepNumber = 4;
            invalidModel.ProjectForm = form;
            return View(nameof(Index), invalidModel);
        }

        try
        {
            await onboarding.SaveProjectAsync(form);
        }
        catch (InvalidOperationException ex)
        {
            ModelState.AddModelError(string.Equals(form.Mode, OnboardingSelectionModes.Select, StringComparison.Ordinal)
                ? nameof(form.SelectedProjectID)
                : nameof(form.ProjectName), ex.Message);
            var invalidModel = await onboarding.GetWizardAsync();
            invalidModel.CurrentStep = OnboardingSteps.Project;
            invalidModel.StepNumber = 4;
            invalidModel.ProjectForm = form;
            return View(nameof(Index), invalidModel);
        }

        return RedirectToAction(nameof(Index));
    }

    [HttpPost("book")]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> Book(BookOnboardingForm form)
    {
        if (string.Equals(form.Mode, OnboardingSelectionModes.Create, StringComparison.Ordinal)
            && string.IsNullOrWhiteSpace(form.BookTitle))
        {
            ModelState.AddModelError(nameof(form.BookTitle), "Enter a book title.");
        }

        if (string.Equals(form.Mode, OnboardingSelectionModes.Select, StringComparison.Ordinal)
            && !form.SelectedBookID.HasValue)
        {
            ModelState.AddModelError(nameof(form.SelectedBookID), "Choose a book from the selected project.");
        }

        if (!ModelState.IsValid)
        {
            var invalidModel = await onboarding.GetWizardAsync();
            invalidModel.CurrentStep = OnboardingSteps.Book;
            invalidModel.StepNumber = 5;
            invalidModel.BookForm = form;
            return View(nameof(Index), invalidModel);
        }

        try
        {
            await onboarding.SaveBookAsync(form);
        }
        catch (SubscriptionLimitException ex)
        {
            ModelState.AddModelError(nameof(form.BookTitle), ex.Message);
            var invalidModel = await onboarding.GetWizardAsync();
            invalidModel.CurrentStep = OnboardingSteps.Book;
            invalidModel.StepNumber = 5;
            invalidModel.BookForm = form;
            return View(nameof(Index), invalidModel);
        }
        catch (InvalidOperationException ex)
        {
            ModelState.AddModelError(string.Equals(form.Mode, OnboardingSelectionModes.Select, StringComparison.Ordinal)
                ? nameof(form.SelectedBookID)
                : nameof(form.BookTitle), ex.Message);
            var invalidModel = await onboarding.GetWizardAsync();
            invalidModel.CurrentStep = OnboardingSteps.Book;
            invalidModel.StepNumber = 5;
            invalidModel.BookForm = form;
            return View(nameof(Index), invalidModel);
        }

        return RedirectToAction(nameof(Index));
    }

    [HttpPost("finish")]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> Finish()
    {
        await onboarding.MarkCompletedAsync();
        TempData["ArchiveMessage"] = "Setup saved. You can return to setup preferences from your account menu.";
        return RedirectToAction("Index", "Projects");
    }

    [HttpPost("back")]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> Back(string currentStep)
    {
        var targetStep = currentStep switch
        {
            OnboardingSteps.WritingJourney => OnboardingSteps.Welcome,
            OnboardingSteps.WritingSoftware => OnboardingSteps.WritingJourney,
            OnboardingSteps.Project => OnboardingSteps.WritingSoftware,
            OnboardingSteps.Book => OnboardingSteps.Project,
            OnboardingSteps.NextPathPreview => OnboardingSteps.Book,
            _ => OnboardingSteps.Welcome
        };

        await onboarding.SetCurrentStepAsync(targetStep);

        return RedirectToAction(nameof(Index));
    }
}