using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Windows.Forms;

namespace HeuristicLab.ExperimentGeneration.DataAnalysis.Wizard {
  public enum WizardButtons {
    None,
    Back,
    Next,
    Commit
  }
  public partial class Wizard : Form {
    private IList<WizardPage> wizardPages;
    public IList<WizardPage> WizardPages {
      get { return wizardPages; }
    }

    private WizardPage activePage;
    public WizardPage ActivePage {
      get { return activePage; }
    }

    public Wizard() {
      InitializeComponent();
      wizardPages = new List<WizardPage>();
    }

    public void SetActivePage(int pageIndex) {
      if (pageIndex < 0 || pageIndex >= wizardPages.Count) {
        throw new ArgumentOutOfRangeException("pageIndex");
      }
      SetActivePage(wizardPages[pageIndex]);
    }

    public void SetActivePage(string pageName) {
      if (string.IsNullOrEmpty(pageName)) {
        throw new ArgumentException("Parameter must not be null or empty", "pageName");
      }
      WizardPage newPage = WizardPages.Single(p => p.Name == pageName);
      if (newPage == null) {
        throw new ArgumentNullException(string.Format("Can't find page with name {0}", pageName));
      } else {
        SetActivePage(newPage);
      }

    }

    public void SetActivePage(WizardPageEventArgs wpea) {
      if (!wpea.Cancel) {
        SetActivePage(wpea.NewPage);
      }
    }

    public void SetActivePage(WizardPage page) {
      WizardPage oldActivePage = activePage;
      if (!pagePanel.Controls.Contains(page)) {
        pagePanel.Controls.Add(page);
      }
      page.Visible = true;
      activePage = page;

      CancelEventArgs e = new CancelEventArgs();
      activePage.OnSetActive(e);
      if (e.Cancel) {
        activePage.Visible = false;
        activePage = oldActivePage;
      }

      foreach (WizardPage wp in WizardPages) {
        if (wp != activePage) {
          wp.Visible = false;
        }
      }
    }

    public void SetWizardButton(WizardButtons button) {
      if (button == WizardButtons.Back) {
        btnBack.Enabled = true;
      } else if (button == WizardButtons.Next) {
        btnCommit.Visible = false;
        btnCommit.Enabled = false;
        btnNext.Visible = true;
        btnNext.Enabled = true;
        AcceptButton = btnNext;
      } else if (button == WizardButtons.Commit) {
        btnCommit.Visible = true;
        btnCommit.Enabled = true;
        btnNext.Visible = false;
        btnNext.Enabled = false;
        AcceptButton = btnCommit;
      }
    }

    public void SetButtonText(WizardButtons button, string buttonText) {
      if (button == WizardButtons.Commit) {
        btnCommit.Text = buttonText;
      }
    }

    protected virtual void OnQueryCancel(CancelEventArgs e) {
      activePage.OnQueryCancel(e);
    }

    private void SetWizardSizeToFitAllPages() {
      System.Drawing.Size maxPageSize = new System.Drawing.Size(controlPanel.Width, 0);
      foreach (WizardPage page in WizardPages) {
        if (page.Width > maxPageSize.Width) {
          maxPageSize.Width = page.Width;
        }
        if (page.Height > maxPageSize.Height) {
          maxPageSize.Height = page.Height;
        }
      }
      foreach (WizardPage page in WizardPages) {
        page.Size = maxPageSize;
      }
      System.Drawing.Size newSize = maxPageSize + (Size - pagePanel.Size);
      Size = newSize;
    }

    private WizardPageEventArgs BuildChangePageEventArgs(int delta) {
      int activePageIndex = WizardPages.IndexOf(ActivePage);
      int nextPageIndex = activePageIndex + delta;

      if (nextPageIndex < 0 || nextPageIndex >= WizardPages.Count)
        nextPageIndex = activePageIndex;

      WizardPage nextPage = WizardPages[nextPageIndex];
      WizardPageEventArgs wpea = new WizardPageEventArgs();
      wpea.NewPage = nextPage.Name;
      wpea.Cancel = false;

      return wpea;
    }

    private void btnNext_Click(object sender, EventArgs e) {
      WizardPageEventArgs wpea = BuildChangePageEventArgs(1);
      ActivePage.OnWizardNext(wpea);
      SetActivePage(wpea);
    }

    private void btnBack_Click(object sender, EventArgs e) {
      WizardPageEventArgs wpea = BuildChangePageEventArgs(-1);
      ActivePage.OnWizardBack(wpea);
      SetActivePage(wpea);
    }

    private void btnCommit_Click(object sender, EventArgs e) {
      CancelEventArgs cea = new CancelEventArgs();
      ActivePage.OnWizardCommit(cea);
      if (!cea.Cancel) {
        DialogResult = DialogResult.OK;
        Close();
      }
    }

    private void btnCancel_Click(object sender, EventArgs e) {
      DialogResult = DialogResult.Cancel;
      Close();
    }

    private void Wizard_Load(object sender, EventArgs e) {
      if (WizardPages.Count > 0) {
        SetWizardSizeToFitAllPages();
        SetActivePage(0);
      } else {
        SetWizardButton(WizardButtons.None);
      }
    }

    private void Wizard_Closing(object sender, CancelEventArgs e) {
      if (!btnCancel.Enabled) {
        e.Cancel = true;
      } else if (btnCommit.Enabled) {
        OnQueryCancel(e);
      }
    }
  }
}