import { execSync } from "node:child_process"

interface GitFileStat {
  path: string
  added: number
  removed: number
  status: "modified" | "added" | "deleted"
}

export function getGitDiffStats(directory: string): GitFileStat[] {
  try {
    const statusOutput = execSync("git status --porcelain", {
      cwd: directory,
      encoding: "utf-8",
      timeout: 5000,
      stdio: ["pipe", "pipe", "pipe"],
    }).trim()

    if (!statusOutput) return []

    const statusMap = new Map<string, "modified" | "added" | "deleted">()
    const untrackedFiles: string[] = []
    for (const line of statusOutput.split("\n")) {
      if (!line) continue
      const status = line.substring(0, 2).trim()
      const filePath = line.substring(3)
      if (status === "??") {
        statusMap.set(filePath, "added")
        untrackedFiles.push(filePath)
      } else if (status === "A") {
        statusMap.set(filePath, "added")
      } else if (status === "D") {
        statusMap.set(filePath, "deleted")
      } else {
        statusMap.set(filePath, "modified")
      }
    }

    const output = execSync("git diff --numstat HEAD", {
      cwd: directory,
      encoding: "utf-8",
      timeout: 5000,
      stdio: ["pipe", "pipe", "pipe"],
    }).trim()

    const stats: GitFileStat[] = []
    const trackedPaths = new Set<string>()

    if (output) {
      for (const line of output.split("\n")) {
        const parts = line.split("\t")
        if (parts.length < 3) continue

        const [addedStr, removedStr, path] = parts
        const added = addedStr === "-" ? 0 : parseInt(addedStr, 10)
        const removed = removedStr === "-" ? 0 : parseInt(removedStr, 10)
        trackedPaths.add(path)

        stats.push({
          path,
          added,
          removed,
          status: statusMap.get(path) ?? "modified",
        })
      }
    }

    for (const filePath of untrackedFiles) {
      if (trackedPaths.has(filePath)) continue
      try {
        const content = execSync(`wc -l < "${filePath}"`, {
          cwd: directory,
          encoding: "utf-8",
          timeout: 3000,
          stdio: ["pipe", "pipe", "pipe"],
        }).trim()
        const lineCount = parseInt(content, 10) || 0
        stats.push({ path: filePath, added: lineCount, removed: 0, status: "added" })
      } catch {
        stats.push({ path: filePath, added: 0, removed: 0, status: "added" })
      }
    }

    return stats
  } catch {
    return []
  }
}

export function formatFileChanges(stats: GitFileStat[], notepadPath?: string): string {
  if (stats.length === 0) return "[FILE CHANGES SUMMARY]\nNo file changes detected.\n"

  const modified = stats.filter((s) => s.status === "modified")
  const added = stats.filter((s) => s.status === "added")
  const deleted = stats.filter((s) => s.status === "deleted")

  const lines: string[] = ["[FILE CHANGES SUMMARY]"]

  if (modified.length > 0) {
    lines.push("Modified files:")
    for (const f of modified) {
      lines.push(`  ${f.path}  (+${f.added}, -${f.removed})`)
    }
    lines.push("")
  }

  if (added.length > 0) {
    lines.push("Created files:")
    for (const f of added) {
      lines.push(`  ${f.path}  (+${f.added})`)
    }
    lines.push("")
  }

  if (deleted.length > 0) {
    lines.push("Deleted files:")
    for (const f of deleted) {
      lines.push(`  ${f.path}  (-${f.removed})`)
    }
    lines.push("")
  }

  if (notepadPath) {
    const notepadStat = stats.find((s) => s.path.includes("notepad") || s.path.includes(".sisyphus"))
    if (notepadStat) {
      lines.push("[NOTEPAD UPDATED]")
      lines.push(`  ${notepadStat.path}  (+${notepadStat.added})`)
      lines.push("")
    }
  }

  return lines.join("\n")
}