import { writeFileSync } from "node:fs";
import { join } from "node:path";
import { type } from "arktype";
import { log } from "../utils/cli.ts";
import { formatFilesWithLineNumbers, type DiffFile } from "./checkout.ts";
import type { ToolContext } from "./server.ts";
import { execute, tool } from "./shared.ts";

export const CommitInfo = type({
  sha: type.string.describe("the commit SHA (full or abbreviated) to fetch"),
});

export function CommitInfoTool(ctx: ToolContext) {
  return tool({
    name: "get_commit_info",
    description:
      "Retrieve commit metadata and diff via Gitea API. Returns diffPath pointing to formatted diff file. " +
      'Example: `get_commit_info({ sha: "2a6ab5d" })`.',
    parameters: CommitInfo,
    execute: execute(async ({ sha }) => {
      const result = await ctx.gitea.rest.repository.repoGetSingleCommit({
        owner: ctx.repo.owner,
        repo: ctx.repo.name,
        sha,
      });
      const data = result.data;

      // The SDK's CommitAffectedFiles type omits `patch`, which Gitea does return
      // in practice. Cast explicitly so we can pass it to formatFilesWithLineNumbers.
      const files: DiffFile[] = (data.files ?? []).map((f) => ({
        filename: f.filename,
        patch: (f as unknown as { patch?: string }).patch,
      }));

      const formatResult = formatFilesWithLineNumbers(files);
      const tempDir = process.env.SHOCKBOT_TEMP_DIR;
      if (!tempDir) {
        throw new Error("SHOCKBOT_TEMP_DIR not set - get_commit_info must run in shockbot action context");
      }
      const diffFile = join(tempDir, `commit-${sha.slice(0, 7)}.diff`);
      writeFileSync(diffFile, formatResult.content);
      log.debug(`wrote commit diff to ${diffFile} (${formatResult.content.length} bytes)`);

      return {
        sha: data.sha,
        message: data.commit?.message,
        author: data.author?.login ?? data.commit?.author?.name ?? null,
        committer: data.committer?.login ?? data.commit?.committer?.name ?? null,
        date: data.commit?.author?.date ?? data.commit?.committer?.date ?? "",
        url: data.html_url,
        parents: (data.parents ?? []).map((p) => p.sha),
        stats: data.stats ?? { additions: 0, deletions: 0, total: 0 },
        fileCount: files.length,
        diffFile,
      };
    }),
  });
}