1 files changed, 113 insertions, 0 deletions
diff --git a/packages/server/src/git/patch.ts b/packages/server/src/git/patch.ts
new file mode 100644
index 0000000..71d9193
--- /dev/null
+++ b/packages/server/src/git/patch.ts
@@ -0,0 +1,113 @@
+import { Diff } from "./diff";
+import { ConvenientPatch as NodeGitPatch } from "nodegit";
+
+type Hunk = {
+	new_start: number,
+	new_lines_cnt: number,
+	old_start: number,
+	old_lines_cnt: number,
+	new_lines: number[],
+	deleted_lines: number[],
+	hunk: string
+}
+
+type Hunks = {
+	prev: null | number,
+	hunks: Hunk[]
+}
+
+function getHunkContent(hunk: string[]) {
+	interface Lines {
+		new_lines: number[],
+		deleted_lines: number[]
+	}
+
+	const lines = hunk.reduce((result: Lines, line, index) => {
+		if(line.charAt(0) === "+") {
+			hunk[index] = line.slice(1);
+			result.new_lines.push(index);
+		}
+		else if(line.charAt(0) === "-") {
+			hunk[index] = line.slice(1);
+			result.deleted_lines.push(index);
+		}
+		return result;
+	}, { new_lines: [], deleted_lines: [] });
+
+	return { ...lines, hunk: hunk.join("\n") };
+}
+
+export class Patch {
+	private _ng_patch: NodeGitPatch;
+
+	public from: string;
+	public to: string;
+	public additions: number;
+	public deletions: number;
+	public too_large = false;
+	public content: string | null = null;
+
+	constructor(diff: Diff, patch: NodeGitPatch, index: number) {
+		this._ng_patch = patch;
+
+		this.from = patch.oldFile().path();
+		this.to = patch.newFile().path();
+		this.additions = patch.lineStats()["total_additions"];
+		this.deletions = patch.lineStats()["total_deletions"];
+
+		const raw_patches_arr = diff.raw_patches.split("\n");
+		const start = diff.patch_header_indexes[index] + diff.patch_header_lengths[index];
+		const end = (typeof diff.patch_header_indexes[index + 1] === "undefined") ? raw_patches_arr.length - 1 : diff.patch_header_indexes[index + 1];
+
+		const patch_content = raw_patches_arr.slice(start, end);
+
+		if(patch_content.length !== 0) {
+			this.content = patch_content.join("\n");
+
+			const line_lengths = patch_content.map(line => line.length).reduce((result, length) => result + length);
+
+			if(patch_content.length > 5000 || line_lengths > 5000) {
+				this.too_large = true;
+			}
+		}
+	}
+
+	async getHunks(): Promise<Hunk[] | null> {
+		if(!this.content) {
+			return null;
+		}
+
+		const content = this.content.split("\n");
+		const hunks = await this._ng_patch.hunks();
+
+		const hunks_data = hunks.reduce((result: Hunks, hunk, hunk_index) => {
+			const hunk_header = hunk.header();
+			const hunk_header_index = content.indexOf(hunk_header.replace(/\n/gu, ""));
+
+			if(result.prev !== null) {
+				const prev_hunk = hunks[hunk_index - 1];
+				result.hunks.push({
+					new_start: prev_hunk.newStart(),
+					new_lines_cnt: prev_hunk.newLines(),
+					old_start: prev_hunk.oldStart(),
+					old_lines_cnt: prev_hunk.oldLines(),
+					...getHunkContent(content.slice(result.prev, hunk_header_index))
+				});
+			}
+
+			result.prev = hunk_header_index;
+			return result;
+		}, { prev: null, hunks: [] });
+
+		const prev_hunk = hunks[hunks.length - 1];
+		hunks_data.hunks.push({
+			new_start: prev_hunk.newStart(),
+			new_lines_cnt: prev_hunk.newLines(),
+			old_start: prev_hunk.oldStart(),
+			old_lines_cnt: prev_hunk.oldLines(),
+			...getHunkContent(content.slice(<number>hunks_data.prev))
+		});
+
+		return hunks_data.hunks;
+	}
+}
+\ No newline at end of file