oh-my-opencode/src/tools/ast-grep/sg-compact-json-output.ts

import { DEFAULT_MAX_MATCHES, DEFAULT_MAX_OUTPUT_BYTES } from "./constants"
import type { CliMatch, SgResult } from "./types"

export function createSgResultFromStdout(stdout: string): SgResult {
	if (!stdout.trim()) {
		return { matches: [], totalMatches: 0, truncated: false }
	}

	const outputTruncated = stdout.length >= DEFAULT_MAX_OUTPUT_BYTES
	const outputToProcess = outputTruncated ? stdout.substring(0, DEFAULT_MAX_OUTPUT_BYTES) : stdout

	let matches: CliMatch[] = []
	try {
		matches = JSON.parse(outputToProcess) as CliMatch[]
	} catch {
		if (outputTruncated) {
			try {
				const lastValidIndex = outputToProcess.lastIndexOf("}")
				if (lastValidIndex > 0) {
					const bracketIndex = outputToProcess.lastIndexOf("},", lastValidIndex)
					if (bracketIndex > 0) {
						const truncatedJson = outputToProcess.substring(0, bracketIndex + 1) + "]"
						matches = JSON.parse(truncatedJson) as CliMatch[]
					}
				}
			} catch {
				return {
					matches: [],
					totalMatches: 0,
					truncated: true,
					truncatedReason: "max_output_bytes",
					error: "Output too large and could not be parsed",
				}
			}
		} else {
			return { matches: [], totalMatches: 0, truncated: false }
		}
	}

	const totalMatches = matches.length
	const matchesTruncated = totalMatches > DEFAULT_MAX_MATCHES
	const finalMatches = matchesTruncated ? matches.slice(0, DEFAULT_MAX_MATCHES) : matches

	return {
		matches: finalMatches,
		totalMatches,
		truncated: outputTruncated || matchesTruncated,
		truncatedReason: outputTruncated
			? "max_output_bytes"
			: matchesTruncated
				? "max_matches"
				: undefined,
	}
}