import MGNEActorSheet from "./base-actor-sheet.mjs"

const SYSTEM_ID = "fvtt-machine-gods-noxian-expanse"

const PARTY_LOOT_TYPES = new Set(["weapon", "armor", "shield", "equipment", "resonance-core", "artifact"])

export default class MGNEPartySheet extends MGNEActorSheet {
  /** @override */
  static DEFAULT_OPTIONS = {
    classes: ["party"],
    position: { width: 820, height: 640 },
    actions: {
      openMember: MGNEPartySheet.#onOpenMember,
      removeMember: MGNEPartySheet.#onRemoveMember,
      moveMemberUp: MGNEPartySheet.#onMoveMemberUp,
      moveMemberDown: MGNEPartySheet.#onMoveMemberDown,
      adjustCredits: MGNEPartySheet.#onAdjustCredits,
    },
  }

  /** @override */
  static PARTS = {
    main: { template: `systems/${SYSTEM_ID}/templates/party-main.hbs` },
    tabs: { template: `systems/${SYSTEM_ID}/templates/party-tabs.hbs` },
    members: { template: `systems/${SYSTEM_ID}/templates/party-members.hbs` },
    loot: { template: `systems/${SYSTEM_ID}/templates/party-loot.hbs` },
    notes: { template: `systems/${SYSTEM_ID}/templates/party-notes.hbs` },
  }

  tabGroups = { sheet: "members" }

  #getTabs() {
    const tabs = {
      members: { id: "members", group: "sheet", label: game.i18n.localize("MGNE.Tabs.members") },
      loot: { id: "loot", group: "sheet", label: game.i18n.localize("MGNE.Tabs.loot") },
      notes: { id: "notes", group: "sheet", label: game.i18n.localize("MGNE.Tabs.notes") },
    }
    for (const tab of Object.values(tabs)) {
      tab.active = this.tabGroups[tab.group] === tab.id
      tab.cssClass = tab.active ? "active" : ""
    }
    return tabs
  }

  /** @override */
  async _prepareContext() {
    const context = await super._prepareContext()
    context.tabs = this.#getTabs()
    return context
  }

  /** @override */
  async _preparePartContext(partId, context) {
    const doc = this.document
    switch (partId) {
      case "members": {
        context.tab = context.tabs.members
        // Build member list using actorId for moves; store refIdx (position in
        // memberRefs) so move actions always operate on the correct slot even
        // when some refs point to deleted actors.
        const refs = doc.system.memberRefs ?? []
        const members = []
        for (let refIdx = 0; refIdx < refs.length; refIdx++) {
          const actor = game.actors?.get(refs[refIdx].id)
          if (!actor) continue
          members.push({
            id: actor.id,
            refIdx,
            name: actor.name,
            img: actor.img,
            type: actor.type,
            typeLabel: game.i18n.localize(`TYPES.Actor.${actor.type}`),
            hp: actor.system.hp
              ? `${actor.system.hp.value ?? "—"}/${actor.system.hp.max ?? "—"}`
              : "—",
          })
        }
        // isFirst/isLast based on visible list, but swap uses refIdx
        for (let vi = 0; vi < members.length; vi++) {
          members[vi].isFirst = vi === 0
          members[vi].isLast = vi === members.length - 1
        }
        context.members = members
        break
      }

      case "loot": {
        context.tab = context.tabs.loot
        context.lootItems = doc.items.contents
          .filter(i => PARTY_LOOT_TYPES.has(i.type))
          .map(i => ({
            id: i.id,
            img: i.img,
            name: i.name,
            typeLabel: game.i18n.localize(`TYPES.Item.${i.type}`),
          }))
        break
      }

      case "notes":
        context.tab = context.tabs.notes
        break
    }
    return context
  }

  /** @override */
  async _onDrop(event) {
    if (!this.isEditable) return
    const data = foundry.applications.ux.TextEditor.implementation.getDragEventData(event)

    if (data.type === "Actor") {
      const actor = await fromUuid(data.uuid)
      if (!actor || !["character", "companion"].includes(actor.type)) return
      const refs = foundry.utils.deepClone(this.document.system.memberRefs ?? [])
      if (refs.some(r => r.id === actor.id)) return
      refs.push({ id: actor.id })
      return this.document.update({ "system.memberRefs": refs })
    }

    if (data.type === "Item") {
      const item = await fromUuid(data.uuid)
      if (!item || !PARTY_LOOT_TYPES.has(item.type)) return
      return this.document.createEmbeddedDocuments("Item", [item.toObject()])
    }
  }

  // ── Actions ─────────────────────────────────────────────────────────────────

  static async #onOpenMember(_event, target) {
    const actor = game.actors?.get(target.dataset.actorId)
    if (actor) actor.sheet.render(true)
  }

  static async #onRemoveMember(_event, target) {
    const id = target.dataset.actorId
    const refs = (this.document.system.memberRefs ?? []).filter(r => r.id !== id)
    await this.document.update({ "system.memberRefs": refs })
  }

  static async #onMoveMemberUp(_event, target) {
    const refIdx = parseInt(target.dataset.refIdx, 10)
    if (refIdx <= 0) return
    const refs = foundry.utils.deepClone(this.document.system.memberRefs ?? []);
    [refs[refIdx - 1], refs[refIdx]] = [refs[refIdx], refs[refIdx - 1]]
    await this.document.update({ "system.memberRefs": refs })
  }

  static async #onMoveMemberDown(_event, target) {
    const refIdx = parseInt(target.dataset.refIdx, 10)
    const refs = foundry.utils.deepClone(this.document.system.memberRefs ?? [])
    if (refIdx >= refs.length - 1) return;
    [refs[refIdx], refs[refIdx + 1]] = [refs[refIdx + 1], refs[refIdx]]
    await this.document.update({ "system.memberRefs": refs })
  }

  static async #onAdjustCredits(_event, target) {
    const delta = parseInt(target.dataset.delta, 10)
    const current = this.document.system.credits ?? 0
    await this.document.update({ "system.credits": Math.max(0, current + delta) })
  }
}