/**
 * Lint / structural-test / eval config emitters.
 *
 * v1 ships canonical templates per detected stack. The Design stage picks one tool per
 * category; this module produces the config string for that tool. Implementation tasks
 * write the file; Validate verifies the tool runs cleanly.
 *
 * We deliberately avoid bundling the actual tools — Plan tasks install them via the
 * package manager.
 */

export interface LintConfigInput {
  tool: string;
  /** Detected language(s) — used to scope rule sets where the tool requires it. */
  languages: readonly string[];
}

export function renderLintConfig(input: LintConfigInput): { filename: string; content: string } | null {
  switch (input.tool) {
    case "eslint":
      return {
        filename: "eslint.config.js",
        content: [
          "// Generated by /supi:harness. Edit with care; harness re-emits on rebuild.",
          "import js from \"@eslint/js\";",
          "",
          "export default [",
          "  js.configs.recommended,",
          "  {",
          "    rules: {",
          "      // Harness-enforced: prevents the most common slop traps.",
          "      \"no-unused-vars\": [\"error\", { argsIgnorePattern: \"^_\" }],",
          "      \"no-duplicate-imports\": \"error\",",
          "      \"no-unreachable\": \"error\",",
          "    },",
          "  },",
          "];",
          "",
        ].join("\n"),
      };
    case "biome":
      return {
        filename: "biome.json",
        content: JSON.stringify(
          {
            $schema: "https://biomejs.dev/schemas/1.9.0/schema.json",
            organizeImports: { enabled: true },
            linter: {
              enabled: true,
              rules: {
                recommended: true,
                correctness: { noUnusedVariables: "error", noUnreachable: "error" },
                style: { noDuplicateImports: "error" },
              },
            },
          },
          null,
          2,
        ) + "\n",
      };
    case "ruff":
      return {
        filename: "ruff.toml",
        content: [
          "# Generated by /supi:harness.",
          "select = [\"E\", \"F\", \"W\"]",
          "ignore = []",
          "line-length = 100",
          "",
        ].join("\n"),
      };
    default:
      return null;
  }
}

export function renderStructuralTestConfig(input: { tool: string }): { filename: string; content: string } | null {
  switch (input.tool) {
    case "dependency-cruiser":
      return {
        filename: ".dependency-cruiser.cjs",
        content: [
          "// Generated by /supi:harness — structural test config.",
          "module.exports = {",
          "  forbidden: [",
          "    {",
          "      name: \"no-circular\",",
          "      severity: \"error\",",
          "      from: {},",
          "      to: { circular: true },",
          "    },",
          "  ],",
          "  options: { tsConfig: { fileName: \"tsconfig.json\" } },",
          "};",
          "",
        ].join("\n"),
      };
    case "import-linter":
      return {
        filename: ".importlinter",
        content: [
          "[importlinter]",
          "root_packages =",
          "    src",
          "",
          "[importlinter:contract:layers]",
          "name = Layered architecture",
          "type = layers",
          "layers =",
          "    domain",
          "    infrastructure",
          "    ui",
          "",
        ].join("\n"),
      };
    default:
      return null;
  }
}

export function renderEvalConfig(input: { tool: string }): { filename: string; content: string } | null {
  switch (input.tool) {
    case "vitest":
      return {
        filename: "tests/evals/.gitkeep",
        content: "# Eval suite skeleton — populate with /supi:harness implement.\n",
      };
    case "playwright":
      return {
        filename: "tests/evals/.gitkeep",
        content: "# Eval suite skeleton (Playwright e2e). Populate with /supi:harness implement.\n",
      };
    default:
      return null;
  }
}