| b69ab31 | | | 1 | /** |
| b69ab31 | | | 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| b69ab31 | | | 3 | * |
| b69ab31 | | | 4 | * This source code is licensed under the MIT license found in the |
| b69ab31 | | | 5 | * LICENSE file in the root directory of this source tree. |
| b69ab31 | | | 6 | */ |
| b69ab31 | | | 7 | |
| b69ab31 | | | 8 | import type {CommitRev} from './commitStackState'; |
| b69ab31 | | | 9 | |
| b69ab31 | | | 10 | import {List, Record} from 'immutable'; |
| b69ab31 | | | 11 | import {CommitStackState} from './commitStackState'; |
| b69ab31 | | | 12 | |
| b69ab31 | | | 13 | type ReorderResult = { |
| b69ab31 | | | 14 | /** Offset of the move. Positive: move up. Negative: move down. */ |
| b69ab31 | | | 15 | offset: number; |
| b69ab31 | | | 16 | |
| b69ab31 | | | 17 | /** Reorder result that satisfy dependencies. */ |
| b69ab31 | | | 18 | order: CommitRev[]; |
| b69ab31 | | | 19 | |
| b69ab31 | | | 20 | /** Dependent revs that are also moved. */ |
| b69ab31 | | | 21 | deps: CommitRev[]; |
| b69ab31 | | | 22 | }; |
| b69ab31 | | | 23 | |
| b69ab31 | | | 24 | function* range( |
| b69ab31 | | | 25 | start: number, |
| b69ab31 | | | 26 | end: number, |
| b69ab31 | | | 27 | filterFunc?: (i: CommitRev) => boolean, |
| b69ab31 | | | 28 | ): IterableIterator<CommitRev> { |
| b69ab31 | | | 29 | for (let i = start; i < end; i++) { |
| b69ab31 | | | 30 | if (filterFunc && !filterFunc(i as CommitRev)) { |
| b69ab31 | | | 31 | continue; |
| b69ab31 | | | 32 | } |
| b69ab31 | | | 33 | yield i as CommitRev; |
| b69ab31 | | | 34 | } |
| b69ab31 | | | 35 | } |
| b69ab31 | | | 36 | |
| b69ab31 | | | 37 | /** |
| b69ab31 | | | 38 | * Reorder 0..n (exclusive) by moving `origRev` by `offset`. |
| b69ab31 | | | 39 | * Respect `depMap`. |
| b69ab31 | | | 40 | */ |
| b69ab31 | | | 41 | export function reorderWithDeps( |
| b69ab31 | | | 42 | n: number, |
| b69ab31 | | | 43 | origRev: CommitRev, |
| b69ab31 | | | 44 | desiredOffset: number, |
| b69ab31 | | | 45 | depMap: Readonly<Map<CommitRev, Set<CommitRev>>>, |
| b69ab31 | | | 46 | ): Readonly<ReorderResult> { |
| b69ab31 | | | 47 | const offset = |
| b69ab31 | | | 48 | origRev + desiredOffset < 0 |
| b69ab31 | | | 49 | ? -origRev |
| b69ab31 | | | 50 | : origRev + desiredOffset >= n |
| b69ab31 | | | 51 | ? n - 1 - origRev |
| b69ab31 | | | 52 | : desiredOffset; |
| b69ab31 | | | 53 | |
| b69ab31 | | | 54 | let order: CommitRev[] = []; |
| b69ab31 | | | 55 | const deps: CommitRev[] = [origRev]; |
| b69ab31 | | | 56 | const filterFunc = (i: CommitRev) => !deps.includes(i); |
| b69ab31 | | | 57 | if (offset < 0) { |
| b69ab31 | | | 58 | // Moved down. |
| b69ab31 | | | 59 | const depRevs = new Set(depMap.get(origRev) ?? []); |
| b69ab31 | | | 60 | for (let i = -1; i >= offset; i--) { |
| b69ab31 | | | 61 | const rev = (origRev + i) as CommitRev; |
| b69ab31 | | | 62 | if (depRevs.has(rev)) { |
| b69ab31 | | | 63 | deps.push(rev); |
| b69ab31 | | | 64 | depMap.get(rev)?.forEach(r => depRevs.add(r)); |
| b69ab31 | | | 65 | } |
| b69ab31 | | | 66 | } |
| b69ab31 | | | 67 | deps.reverse(); |
| b69ab31 | | | 68 | order = [...range(0, origRev + offset), ...deps, ...range(origRev + offset, n, filterFunc)]; |
| b69ab31 | | | 69 | } else if (offset > 0) { |
| b69ab31 | | | 70 | // Moved up. |
| b69ab31 | | | 71 | for (let i = 1; i <= offset; i++) { |
| b69ab31 | | | 72 | const rev = (origRev + i) as CommitRev; |
| b69ab31 | | | 73 | const dep = depMap.get(rev); |
| b69ab31 | | | 74 | if (dep && (dep.has(origRev) || deps.some(r => dep.has(r)))) { |
| b69ab31 | | | 75 | deps.push(rev); |
| b69ab31 | | | 76 | } |
| b69ab31 | | | 77 | } |
| b69ab31 | | | 78 | order = [ |
| b69ab31 | | | 79 | ...range(0, origRev + offset + 1, filterFunc), |
| b69ab31 | | | 80 | ...deps, |
| b69ab31 | | | 81 | ...range(origRev + offset + 1, n, filterFunc), |
| b69ab31 | | | 82 | ]; |
| b69ab31 | | | 83 | } else { |
| b69ab31 | | | 84 | // Nothing moved. |
| b69ab31 | | | 85 | order = [...range(0, n)]; |
| b69ab31 | | | 86 | } |
| b69ab31 | | | 87 | return {offset, order, deps}; |
| b69ab31 | | | 88 | } |
| b69ab31 | | | 89 | |
| b69ab31 | | | 90 | /** State to preview effects of drag-n-drop reorder. */ |
| b69ab31 | | | 91 | export class ReorderState extends Record({ |
| b69ab31 | | | 92 | offset: 0, |
| b69ab31 | | | 93 | commitStack: new CommitStackState([]), |
| b69ab31 | | | 94 | reorderRevs: List<CommitRev>(), |
| b69ab31 | | | 95 | draggingRevs: List<CommitRev>(), |
| b69ab31 | | | 96 | draggingRev: -1 as CommitRev, |
| b69ab31 | | | 97 | }) { |
| b69ab31 | | | 98 | static init(commitStack: CommitStackState, draggingRev: CommitRev): ReorderState { |
| b69ab31 | | | 99 | return new ReorderState({ |
| b69ab31 | | | 100 | offset: 0, |
| b69ab31 | | | 101 | commitStack, |
| b69ab31 | | | 102 | draggingRev, |
| b69ab31 | | | 103 | reorderRevs: List(commitStack.revs()), |
| b69ab31 | | | 104 | draggingRevs: List([draggingRev]), |
| b69ab31 | | | 105 | }); |
| b69ab31 | | | 106 | } |
| b69ab31 | | | 107 | |
| b69ab31 | | | 108 | isDragging() { |
| b69ab31 | | | 109 | return this.draggingRev >= 0; |
| b69ab31 | | | 110 | } |
| b69ab31 | | | 111 | |
| b69ab31 | | | 112 | /** Returns true if the reorder does nothing. */ |
| b69ab31 | | | 113 | isNoop(): boolean { |
| b69ab31 | | | 114 | return this.offset === 0; |
| b69ab31 | | | 115 | } |
| b69ab31 | | | 116 | |
| b69ab31 | | | 117 | /** |
| b69ab31 | | | 118 | * Calculate reorderRevs and draggingRevs based on the given offset. |
| b69ab31 | | | 119 | * `draggingRevs` might change to maintain the dependency map. |
| b69ab31 | | | 120 | */ |
| b69ab31 | | | 121 | withOffset(offset: number): ReorderState { |
| b69ab31 | | | 122 | const reordered = reorderWithDeps( |
| b69ab31 | | | 123 | this.commitStack.stack.size, |
| b69ab31 | | | 124 | this.draggingRev, |
| b69ab31 | | | 125 | offset, |
| b69ab31 | | | 126 | this.commitStack.calculateDepMap(), |
| b69ab31 | | | 127 | ); |
| b69ab31 | | | 128 | |
| b69ab31 | | | 129 | // Force match dependency requirements of `rev` by moving dependencies. |
| b69ab31 | | | 130 | return this.merge({ |
| b69ab31 | | | 131 | reorderRevs: List(reordered.order), |
| b69ab31 | | | 132 | draggingRevs: List(reordered.deps), |
| b69ab31 | | | 133 | offset: reordered.offset, |
| b69ab31 | | | 134 | }); |
| b69ab31 | | | 135 | } |
| b69ab31 | | | 136 | } |