bol/module/applications/sheets/base-item-sheet.mjs

const { HandlebarsApplicationMixin } = foundry.applications.api

/**
 * Base Item Sheet for BoL system using AppV2
 * @extends {ItemSheetV2}
 */
export default class BoLBaseItemSheet extends HandlebarsApplicationMixin(foundry.applications.sheets.ItemSheetV2) {
  constructor(options = {}) {
    super(options)
    this.#dragDrop = this.#createDragDropHandlers()
  }

  #dragDrop

  /** @override */
  static DEFAULT_OPTIONS = {
    classes: ["bol", "sheet", "item"],
    position: {
      width: 650,
      height: 780,
    },
    form: {
      submitOnChange: true,
    },
    window: {
      resizable: true,
    },
    actions: {
      editImage: BoLBaseItemSheet.#onEditImage,
      postItem: BoLBaseItemSheet.#onPostItem,
    },
  }

  /**
   * Tab groups state
   * @type {object}
   */
  tabGroups = { primary: "description" }

  /** @override */
  async _prepareContext() {
    const context = {
      // Document & system
      fields: this.document.schema.fields,
      systemFields: this.document.system.schema.fields,
      item: this.document,
      system: this.document.system,
      source: this.document.toObject(),
      
      // Enriched content
      enrichedDescription: await foundry.applications.ux.TextEditor.implementation.enrichHTML(
        this.document.system.description, 
        { async: true }
      ),
      
      // Properties
      category: this.document.system.category,
      itemProperties: this.document.itemProperties,
      
      // Config & permissions
      config: game.bol.config,
      isGM: game.user.isGM,
      isEditable: this.isEditable,
      
      // CSS classes for template
      cssClass: this.options.classes.join(" "),
      
      // Tab state
      tabs: this._getTabs(),
      activeTab: this.tabGroups.primary || "description"
    }

    // Add careers if item is on an actor
    if (this.document.actor) {
      context.careers = this.document.actor.careers
    }

    // Apply dynamic defaults based on item type
    this._applyDynamicDefaults(context)

    return context
  }

  /**
   * Get tabs configuration
   * @returns {object[]}
   * @private
   */
  _getTabs() {
    return [
      { id: "description", label: "BOL.ui.tab.description", icon: "fa-solid fa-book" },
      { id: "properties", label: "BOL.ui.tab.details", icon: "fa-solid fa-cog" }
    ]
  }

  /**
   * Apply dynamic defaults to context based on item type and category
   * @param {object} context
   * @private
   */
  _applyDynamicDefaults(context) {
    const itemData = context.item

    if (itemData.type === "item") {
      // Set default category
      if (!itemData.system.category) {
        itemData.system.category = "equipment"
      }

      // Handle equipment slot
      if (itemData.system.category === "equipment" && itemData.system.properties.equipable) {
        if (!itemData.system.properties.slot) {
          itemData.system.properties.slot = "-"
        }
      }

      // Handle spell conditions
      if (itemData.system.category === 'spell') {
        if (!itemData.system.properties.mandatoryconditions) {
          itemData.system.properties.mandatoryconditions = []
        }
        if (!itemData.system.properties.optionnalconditions) {
          itemData.system.properties.optionnalconditions = []
        }
        for (let i = 0; i < 4; i++) {
          itemData.system.properties.mandatoryconditions[i] = itemData.system.properties.mandatoryconditions[i] ?? ""
        }
        for (let i = 0; i < 8; i++) {
          itemData.system.properties.optionnalconditions[i] = itemData.system.properties.optionnalconditions[i] ?? ""
        }
      }
    } else if (itemData.type === "feature") {
      // Set default subtype/category
      if (!itemData.system.subtype) {
        itemData.system.category = "origin"
      }
    }
  }

  /** @override */
  _onRender(context, options) {
    super._onRender(context, options)
    this.#dragDrop.forEach((d) => d.bind(this.element))
    this._activateTabs()
    this._activateListeners()
  }

  /**
   * Activate tab navigation
   * @private
   */
  _activateTabs() {
    const nav = this.element.querySelector('nav.tabs[data-group="primary"]')
    if (!nav) return

    const activeTab = this.tabGroups.primary || "description"
    
    // Activate tab links
    nav.querySelectorAll('[data-tab]').forEach(link => {
      const tab = link.dataset.tab
      link.classList.toggle('active', tab === activeTab)
      link.addEventListener('click', (event) => {
        event.preventDefault()
        this.tabGroups.primary = tab
        this.render()
      })
    })

    // Show/hide tab content
    this.element.querySelectorAll('.tab[data-tab]').forEach(content => {
      content.classList.toggle('active', content.dataset.tab === activeTab)
    })
  }

  /**
   * Activate custom listeners
   * @private
   */
  _activateListeners() {
    if (!this.isEditable) return

    // Armor quality change handler
    const armorQuality = this.element.querySelector('.armorQuality')
    if (armorQuality) {
      armorQuality.addEventListener('change', (ev) => {
        const value = ev.currentTarget.value
        const soakFormula = this.element.querySelector('.soakFormula')
        if (soakFormula && game.bol.config.soakFormulas[value]) {
          soakFormula.value = game.bol.config.soakFormulas[value]
        }
      })
    }
  }

  // #region Drag-and-Drop Workflow
  
  /**
   * Create drag-and-drop workflow handlers for this Application
   * @returns {DragDrop[]}
   * @private
   */
  #createDragDropHandlers() {
    return []
  }

  // #endregion

  // #region Actions

  /**
   * Handle editing the item image
   * @param {PointerEvent} event
   * @param {HTMLElement} target
   * @private
   */
  static async #onEditImage(event, target) {
    const fp = new FilePicker({
      current: this.document.img,
      type: "image",
      callback: (path) => {
        this.document.update({ img: path })
      },
    })
    return fp.browse()
  }

  /**
   * Handle posting the item to chat
   * @param {PointerEvent} event
   * @param {HTMLElement} target
   * @private
   */
  static async #onPostItem(event, target) {
    const BoLUtility = (await import("../../system/bol-utility.js")).BoLUtility
    let chatData = foundry.utils.duplicate(this.document)
    if (this.document.actor) {
      chatData.actor = { id: this.document.actor.id }
    }
    BoLUtility.postItem(chatData)
  }

  // #endregion
}