import { execFileSync } from "node:child_process"
import { parseGitStatusPorcelain } from "./parse-status-porcelain"
import { parseGitDiffNumstat } from "./parse-diff-numstat"
import type { GitFileStat } from "./types"

export function collectGitDiffStats(directory: string): GitFileStat[] {
  try {
    const diffOutput = execFileSync("git", ["diff", "--numstat", "HEAD"], {
      cwd: directory,
      encoding: "utf-8",
      timeout: 5000,
      stdio: ["pipe", "pipe", "pipe"],
    }).trim()

    const statusOutput = execFileSync("git", ["status", "--porcelain"], {
      cwd: directory,
      encoding: "utf-8",
      timeout: 5000,
      stdio: ["pipe", "pipe", "pipe"],
    }).trim()

    const untrackedOutput = execFileSync("git", ["ls-files", "--others", "--exclude-standard"], {
      cwd: directory,
      encoding: "utf-8",
      timeout: 5000,
      stdio: ["pipe", "pipe", "pipe"],
    }).trim()

    const untrackedNumstat = untrackedOutput
      ? untrackedOutput
          .split("\n")
          .filter(Boolean)
          .map((filePath) => {
            try {
              const wcOutput = execFileSync("wc", ["-l", "--", filePath], {
                cwd: directory,
                encoding: "utf-8",
                timeout: 5000,
                stdio: ["pipe", "pipe", "pipe"],
              }).trim()

              const [lineCountToken] = wcOutput.split(/\s+/)
              const lineCount = Number(lineCountToken)
              if (!Number.isFinite(lineCount)) return `0\t0\t${filePath}`

              return `${lineCount}\t0\t${filePath}`
            } catch {
              return `0\t0\t${filePath}`
            }
          })
          .join("\n")
      : ""

    const combinedNumstat = [diffOutput, untrackedNumstat].filter(Boolean).join("\n").trim()

    if (!combinedNumstat) return []

    const statusMap = parseGitStatusPorcelain(statusOutput)
    return parseGitDiffNumstat(combinedNumstat, statusMap)
  } catch {
    return []
  }
}