import { readFile, writeFile } from "node:fs/promises";
import { dirname, resolve } from "node:path";
import { fileURLToPath } from "node:url";

import { readAcpxSidecarProtocolVersion } from "./acpx-sidecar-contract.mjs";

const root = resolve(dirname(fileURLToPath(import.meta.url)), "..");
const schema = JSON.parse(
  await readFile(
    resolve(root, "protocol/provider-schemas/acpx-sidecar.schema.json"),
    "utf8",
  ),
);
const commands = schema.$defs.command.enum;
const events = schema.$defs.eventType.enum;
// Mutation wins for compound provider kinds so create-target attestation and
// the normalized readOnly flag cannot disagree across the sidecar boundary.
const toolOperationPrecedence = [
  ["edit", ["edit", "write", "patch"]],
  ["read", ["read"]],
  ["search", ["search", "grep", "find"]],
  ["list", ["list", "glob"]],
];
const protocolVersion = readAcpxSidecarProtocolVersion(schema);
const quote = (value) => JSON.stringify(value);
const rustVariant = (value) =>
  value
    .split(/[._-]/)
    .map((part) => part[0].toUpperCase() + part.slice(1))
    .join("");

const typescript = `// Generated by scripts/generate-acpx-sidecar-contract.mjs. Do not edit.\n\nexport const GENERATED_ACPX_SIDECAR_PROTOCOL_VERSION = ${protocolVersion} as const;\nexport const GENERATED_ACPX_SIDECAR_COMMANDS = [\n${commands.map((value) => `  ${quote(value)},`).join("\n")}\n] as const;\nexport type GeneratedAcpxSidecarCommand =\n  (typeof GENERATED_ACPX_SIDECAR_COMMANDS)[number];\n\nexport const GENERATED_ACPX_SIDECAR_EVENT_TYPES = [\n${events.map((value) => `  ${quote(value)},`).join("\n")}\n] as const;\nexport type GeneratedAcpxSidecarEventType =\n  (typeof GENERATED_ACPX_SIDECAR_EVENT_TYPES)[number];\n\nexport type GeneratedAcpxToolOperation =\n  | "read"\n  | "search"\n  | "list"\n  | "edit"\n  | "execute"\n  | "unknown";\n\nexport const GENERATED_ACPX_TOOL_OPERATION_PRECEDENCE = [\n${toolOperationPrecedence.map(([operation, tokens]) => `  { operation: ${quote(operation)}, tokens: [${tokens.map(quote).join(", ")}] },`).join("\n")}\n] as const;\n\nexport function classifyGeneratedAcpxToolOperation(\n  toolKind: unknown,\n  toolTitle: unknown,\n): GeneratedAcpxToolOperation {\n  const candidate =\n    typeof toolKind === "string" && toolKind\n      ? toolKind\n      : typeof toolTitle === "string"\n        ? toolTitle\n        : "";\n  const normalized = candidate.slice(0, 240).toLowerCase();\n  for (const { operation, tokens } of GENERATED_ACPX_TOOL_OPERATION_PRECEDENCE) {\n    if (tokens.some((token) => normalized.includes(token))) return operation;\n  }\n  return normalized ? "execute" : "unknown";\n}\n`;
const rust = `// Generated by scripts/generate-acpx-sidecar-contract.mjs. Do not edit.\n\npub const GENERATED_ACPX_SIDECAR_PROTOCOL_VERSION: u64 = ${protocolVersion};\n\npub const GENERATED_ACPX_TOOL_OPERATION_PRECEDENCE: &[(&str, &[&str])] = &[\n${toolOperationPrecedence.map(([operation, tokens]) => `    (${quote(operation)}, &[${tokens.map(quote).join(", ")}]),`).join("\n")}\n];\n\npub fn classify_generated_acpx_tool_operation(kind: &str, title: &str) -> &'static str {\n    let kind = kind.to_ascii_lowercase();\n    let title = title.to_ascii_lowercase();\n    let candidate = if kind.is_empty() { &title } else { &kind };\n    for (operation, tokens) in GENERATED_ACPX_TOOL_OPERATION_PRECEDENCE {\n        if tokens.iter().any(|token| candidate.contains(token)) {\n            return operation;\n        }\n    }\n    if candidate.is_empty() {\n        "unknown"\n    } else {\n        "execute"\n    }\n}\n\n#[derive(Clone, Copy, Debug, PartialEq, Eq)]\npub enum GeneratedAcpxSidecarCommand {\n${commands.map((value) => `    ${rustVariant(value)},`).join("\n")}\n}\n\nimpl GeneratedAcpxSidecarCommand {\n    pub const fn as_str(self) -> &'static str {\n        match self {\n${commands.map((value) => `            Self::${rustVariant(value)} => ${quote(value)},`).join("\n")}\n        }\n    }\n}\n\n#[derive(Clone, Copy, Debug, PartialEq, Eq, serde::Deserialize)]\npub enum GeneratedAcpxSidecarEventType {\n${events.map((value) => `    #[serde(rename = ${quote(value)})]\n    ${rustVariant(value)},`).join("\n")}\n}\n`;

// Classification must inspect the same complete provider value in both
// languages. Display-field truncation happens only after operation selection.
const typescriptWithAsciiLowercase = typescript.replace(
  "export function classifyGeneratedAcpxToolOperation(",
  `function lowercaseGeneratedAcpxAscii(value: string): string {
  return value.replace(/[A-Z]/g, (character) =>
    String.fromCharCode(character.charCodeAt(0) + 32),
  );
}

export function classifyGeneratedAcpxToolOperation(`,
);
if (typescriptWithAsciiLowercase === typescript) {
  throw new Error("generated TypeScript ACPX classifier export drifted");
}
const typescriptClassifier = typescriptWithAsciiLowercase.replace(
  "candidate.slice(0, 240).toLowerCase()",
  "lowercaseGeneratedAcpxAscii(candidate)",
);
if (typescriptClassifier === typescriptWithAsciiLowercase) {
  throw new Error("generated TypeScript ACPX classifier template drifted");
}

const outputs = [
  [
    resolve(root, "src/drivers/acpx/generated-sidecar-contract.ts"),
    typescriptClassifier,
  ],
  [
    resolve(
      root,
      "runner/crates/runner-core/src/generated_acpx_sidecar_contract.rs",
    ),
    rust,
  ],
];
if (process.argv.includes("--check")) {
  const stale = [];
  for (const [path, content] of outputs)
    if ((await readFile(path, "utf8").catch(() => "")) !== content)
      stale.push(path);
  if (stale.length > 0) {
    process.stderr.write(
      `Generated ACPX sidecar contracts are stale: ${stale.join(", ")}\n`,
    );
    process.exitCode = 1;
  } else
    process.stdout.write(
      "Generated TypeScript/Rust ACPX sidecar contracts match the schema.\n",
    );
} else {
  await Promise.all(outputs.map(([path, content]) => writeFile(path, content)));
  process.stdout.write("Generated TypeScript/Rust ACPX sidecar contracts.\n");
}