// Copyright 2024 The Lynx Authors. All rights reserved.
// Licensed under the Apache License Version 2.0 that can be found in the
// LICENSE file in the root directory of this source tree.
import { hydrate } from './hydrate.js';
import { componentAtIndexFactory, enqueueComponentFactory, gRecycleMap, gSignMap } from '../list/list.js';
import { CHILDREN } from '../../shared/render-constants.js';
import { SnapshotInstance } from '../snapshot/snapshot.js';

const OpcodeBegin = 0;
const OpcodeEnd = 1;
const OpcodeAttr = 2;
const OpcodeText = 3;

interface SSRFiberElement {
  ssrID: string;
}
export type SSRSnapshotInstance = [string, number, SSRFiberElement[]];

export function ssrHydrateByOpcodes(
  opcodes: any[],
  into: SnapshotInstance,
  refMap?: Record<string, FiberElement>,
): void {
  let top: SnapshotInstance & { __pendingElements?: SSRFiberElement[] } = into;
  const stack: SnapshotInstance[] = [into];
  for (let i = 0; i < opcodes.length;) {
    const opcode = opcodes[i];
    switch (opcode) {
      case OpcodeBegin: {
        const p = top;
        const [type, __id, elements] = opcodes[i + 1] as SSRSnapshotInstance;
        top = new SnapshotInstance(type, __id);
        top.__pendingElements = elements;
        top.__slotIndex = opcodes[i + 2];
        p.insertBefore(top);
        stack.push(top);

        i += 3;
        break;
      }
      case OpcodeEnd: {
        // @ts-ignore
        top[CHILDREN] = undefined;

        top.__elements = top.__pendingElements!.map(({ ssrID }) => refMap![ssrID]!);
        top.__element_root = top.__elements[0];
        delete top.__pendingElements;

        if (top.__snapshot_def.isListHolder) {
          const [, elementIndex] = top.__snapshot_def.slot[0]!;
          const listElement = top.__elements[elementIndex]!;
          const listElementUniqueID = __GetElementUniqueID(listElement);
          const signMap = gSignMap[listElementUniqueID] = new Map();
          gRecycleMap[listElementUniqueID] = new Map();
          const enqueueFunc = enqueueComponentFactory();
          const [componentAtIndex, componentAtIndexes] = componentAtIndexFactory(top.childNodes, hydrate);
          for (const child of top.childNodes) {
            if (child.__element_root) {
              const childElementUniqueID = __GetElementUniqueID(child.__element_root);
              signMap.set(childElementUniqueID, child);
              enqueueFunc(
                listElement,
                listElementUniqueID,
                childElementUniqueID,
              );
            }
          }
          __UpdateListCallbacks(listElement, componentAtIndex, enqueueFunc, componentAtIndexes);
        }

        stack.pop();
        const p = stack[stack.length - 1];
        top = p!;

        i += 1;
        break;
      }
      case OpcodeAttr: {
        const key = opcodes[i + 1];
        const value = opcodes[i + 2];
        top.setAttribute(key, value);

        i += 3;
        break;
      }
      case OpcodeText: {
        const [[type, __id, elements], text] = opcodes[i + 1] as [SSRSnapshotInstance, string];
        const s = new SnapshotInstance(type, __id);
        s.__slotIndex = opcodes[i + 2];
        s.setAttribute(0, text);
        top.insertBefore(s);
        s.__elements = elements.map(({ ssrID }) => refMap![ssrID]!);
        s.__element_root = s.__elements[0];
        i += 3;
        break;
      }
    }
  }
}

// export function renderOpcodesInto(opcodes: any[], into: SnapshotInstance): void {
//   let top: SnapshotInstance = into;
//   const stack: SnapshotInstance[] = [into];
//   for (let i = 0; i < opcodes.length;) {
//     const opcode = opcodes[i];
//     switch (opcode) {
//       case OpcodeBegin: {
//         const p = top;
//         top = opcodes[i + 1];
//         // @ts-ignore
//         if (top.__parent) {
//           // already inserted
//           top = new SnapshotInstance(top.type);
//           opcodes[i + 1] = top;
//         }
//         p.insertBefore(top);
//         stack.push(top);

//         i += 2;
//         break;
//       }
//       case OpcodeEnd: {
//         // @ts-ignore
//         top[CHILDREN] = undefined;

//         stack.pop();
//         const p = stack[stack.length - 1];
//         top = p!;

//         i += 1;
//         break;
//       }
//       case OpcodeAttr: {
//         const key = opcodes[i + 1];
//         const value = opcodes[i + 2];
//         top.setAttribute(key, value);

//         i += 3;
//         break;
//       }
//       case OpcodeText: {
//         const text = opcodes[i + 1];
//         const s = new SnapshotInstance(null as unknown as string);
//         if (__ENABLE_SSR__) {
//           // We need store the just created SnapshotInstance, or it will be lost when we leave the function
//           opcodes[i + 1] = [s, text];
//         }
//         s.setAttribute(0, text);
//         top.insertBefore(s);

//         i += 2;
//         break;
//       }
//     }
//   }
// }