/**
 * ECC Custom Tool: Lint Check
 *
 * Detects the appropriate linter and returns a runnable lint command.
 */

import { tool } from "@opencode-ai/plugin/tool"
import * as path from "path"
import * as fs from "fs"

type Linter = "biome" | "eslint" | "ruff" | "pylint" | "golangci-lint"

export default tool({
  description:
    "Detect linter for a target path and return command for check/fix runs.",
  args: {
    target: tool.schema
      .string()
      .optional()
      .describe("File or directory to lint (default: current directory)"),
    fix: tool.schema
      .boolean()
      .optional()
      .describe("Enable auto-fix mode"),
    linter: tool.schema
      .enum(["biome", "eslint", "ruff", "pylint", "golangci-lint"])
      .optional()
      .describe("Optional linter override"),
  },
  async execute(args, context) {
    const cwd = context.worktree || context.directory
    const target = args.target || "."
    const fix = args.fix ?? false
    const detected = args.linter || detectLinter(cwd)

    const command = buildLintCommand(detected, target, fix)
    return JSON.stringify({
      success: true,
      linter: detected,
      command,
      instructions: `Run this command:\n\n${command}`,
    })
  },
})

function detectLinter(cwd: string): Linter {
  if (fs.existsSync(path.join(cwd, "biome.json")) || fs.existsSync(path.join(cwd, "biome.jsonc"))) {
    return "biome"
  }

  const eslintConfigs = [
    ".eslintrc.json",
    ".eslintrc.js",
    ".eslintrc.cjs",
    "eslint.config.js",
    "eslint.config.mjs",
  ]
  if (eslintConfigs.some((name) => fs.existsSync(path.join(cwd, name)))) {
    return "eslint"
  }

  const pyprojectPath = path.join(cwd, "pyproject.toml")
  if (fs.existsSync(pyprojectPath)) {
    try {
      const content = fs.readFileSync(pyprojectPath, "utf-8")
      if (content.includes("ruff")) return "ruff"
    } catch {
      // ignore read errors and keep fallback logic
    }
  }

  if (fs.existsSync(path.join(cwd, ".golangci.yml")) || fs.existsSync(path.join(cwd, ".golangci.yaml"))) {
    return "golangci-lint"
  }

  return "eslint"
}

function buildLintCommand(linter: Linter, target: string, fix: boolean): string {
  if (linter === "biome") return `npx @biomejs/biome lint${fix ? " --write" : ""} ${target}`
  if (linter === "eslint") return `npx eslint${fix ? " --fix" : ""} ${target}`
  if (linter === "ruff") return `ruff check${fix ? " --fix" : ""} ${target}`
  if (linter === "pylint") return `pylint ${target}`
  return `golangci-lint run ${target}`
}