import { fnv1a64 } from "../worker/replay.mjs";
import { runtimeResourceFixture } from "./resource-resolver.mjs";
import { SIM_CASE_CATALOG, SIM_FILE_INDEX, SIM_HAL_COMPONENTS } from "./sim-case-catalog.mjs";
import { isOptionalSourceKey } from "./linuxcnc-source-semantics.mjs";
import { MACHINE_DEFINITIONS, machineDefinition } from "./machine-definitions.mjs";
import resources from "./simulation-resources.json" with { type: "json" };
import { parseIni } from "./ini-parser.mjs";
import { WorkspaceRuntime } from "./runtime.mjs";
import { readTrtConfiguration } from "./trt-configuration.mjs";

export const SIMULATION_CASE_SCHEMA = "simulation-case-bundle.v1";
const RESOURCE_KEYS = new Set([
  "HAL", "HALFILE", "POSTGUI_HALFILE", "TOOLTABLE", "TOOL_TABLE", "VARFILE", "PARAMETER_FILE", "OPEN_FILE",
  "PROGRAM", "PROGRAMS", "PYTHON", "PYTHONFILE", "VCP", "VCPFILE", "CLPFILE",
  "PYVCP", "NGCGUI_SUBFILE", "INTRO_GRAPHIC", "SUBROUTINE_PATH", "REMAP",
]);
const MANIFEST = new Set(SIM_FILE_INDEX);
const PRELOADED_HAL_COMPONENTS = Object.freeze(resources.preloaded_hal_components);
const CASE_KINEMATICS = Object.freeze(resources.kinematics);
const RUNTIME_FIXTURES = Object.freeze(resources.runtime_fixtures);

function clone(value) { return structuredClone(value); }
function text(value) { return typeof value === "string" && value.trim() ? value.trim() : null; }
function stripQuotes(value) { return value.trim().replace(/^['"]|['"]$/g, ""); }
function dirname(path) { const index = path.lastIndexOf("/"); return index < 0 ? "" : path.slice(0, index); }
function normalize(path) {
  const parts = [];
  for (const part of path.replaceAll("\\", "/").split("/")) {
    if (!part || part === ".") continue;
    if (part === "..") { if (!parts.length) return null; parts.pop(); continue; }
    parts.push(part);
  }
  return parts.join("/");
}
function tokens(value) {
  return (value.match(/(?:[^\s"']+|"[^"]*"|'[^']*')+/g) ?? []).map(stripQuotes);
}
function candidates(source, raw, key = null, section = null) {
  const value = stripQuotes(raw);
  const first = tokens(value)[0] ?? value;
  // LinuxCNC uses quoted empty values (notably DISPLAY/OPEN_FILE) as an
  // explicit "no file" setting; they must not resolve to the source directory.
  if (!first) return [];
  if (String(key).toUpperCase() === "OPEN_FILE") {
    if (first.startsWith("configs/nc_files/")) return [`linuxcnc/${first}`];
    const relative = normalize(`${dirname(source)}/${first}`);
    const marker = first.indexOf("nc_files/");
    const rootCandidate = marker >= 0 ? normalize(`linuxcnc/nc_files/${first.slice(marker + "nc_files/".length)}`) : null;
    const candidates = [relative, rootCandidate].filter(Boolean).filter(inManifest);
    return candidates.length ? [candidates[0]] : [relative].filter(Boolean);
  }
  if (first.startsWith("/") || first.startsWith("~") || first.startsWith("$")) return [first];
  if (String(key).toUpperCase() === "INTRO_GRAPHIC" && String(section).toUpperCase() === "DISPLAY" && first === "linuxcnc.gif") return ["linuxcnc/linuxcnc.gif"];
  if (first.startsWith("LIB:")) {
    const name = first.slice(4);
    if (!name || name.includes("..") || name.startsWith("/")) return [];
    const libraryPath = normalize(`linuxcnc/lib/hallib/${name}`);
    return libraryPath ? [libraryPath] : [];
  }
  if (["NGCGUI_SUBFILE", "REMAP"].includes(String(key).toUpperCase())) {
    const subroutine = normalize(`${dirname(source)}/remap_subs/${first}`);
    if (subroutine) return [subroutine];
  }
  if (["HAL", "HALFILE"].includes(String(key).toUpperCase()) && !first.includes("/") && !first.startsWith("linuxcnc/")) {
    const halCandidates = [normalize(`${dirname(source)}/${first}`), `linuxcnc/lib/hallib/${first}`].filter(Boolean);
    const indexed = halCandidates.filter(inManifest);
    return indexed.length ? [indexed[0]] : halCandidates;
  }
  if (first.startsWith("linuxcnc/")) return [normalize(first)].filter(Boolean);
  const relative = normalize(`${dirname(source)}/${first}`);
  return relative ? [relative] : [first];
}
function includeCandidates(source, raw) {
  const value = stripQuotes(raw);
  if (value.startsWith("linuxcnc/")) return [normalize(value)].filter(Boolean);
  const relative = normalize(`${dirname(source)}/${value}`);
  return relative ? [relative] : [value];
}
function runtimeResourceKey(key) {
  return ["PARAMETER_FILE", "VARFILE", "TOOL_TABLE", "TOOLTABLE"].includes(String(key ?? "").toUpperCase());
}
function generatedResource(path, key) {
  if (typeof path !== "string" || path.startsWith("/") || path.startsWith("~") || path.startsWith("$") || path.split("/").includes("..")) return null;
  const generated = runtimeResourceFixture({ key, path });
  return generated ? { ...generated, data_hash: fnv1a64(generated.content) } : null;
}
function inManifest(path) {
  return MANIFEST.has(path) || path === "linuxcnc/configs/nc_files/3dtest.ngc" || path === "linuxcnc/configs/sim/axis/vismach/5axis/table-rotary-tilting/xyzbc-trt_cmds.hal";
}
function responseUrl(baseUrl, path) { return `${String(baseUrl ?? "").replace(/\/$/, "")}/${path}`.replace(/^\//, "/"); }

async function fetchText(fetchImpl, baseUrl, path) {
  const response = await fetchImpl(responseUrl(baseUrl, path), { cache: "no-store" });
  if (!response?.ok) return null;
  return response.text();
}

function resourceReferences(source, content) {
  const references = [];
  let section = "";
  for (const rawLine of content.split(/\r?\n/)) {
    const include = rawLine.trim().match(/^#?INCLUDE\s*(?:=\s*)?(.+)$/i);
    if (include) {
      references.push(...includeCandidates(source, include[1]).map((path) => ({ path, key: null, source })));
      continue;
    }
    const line = rawLine.split("#", 1)[0].trim();
    const sectionMatch = line.match(/^\[([^\]]+)\]$/);
    if (sectionMatch) { section = sectionMatch[1].trim(); continue; }
    if (section === "RS274NGC" && /^SUBROUTINE_PATH\s*=\s*/i.test(line)) {
      const directory = normalize(`${dirname(source)}/${line.split("=", 2)[1].trim()}`);
      for (const candidate of SIM_FILE_INDEX.filter((path) => directory && path.startsWith(`${directory}/`) && path.endsWith(".ngc"))) references.push({ path: candidate, key: "SUBROUTINE_PATH", section, source });
      continue;
    }
    if (section === "RS274NGC" && /^REMAP\s*=\s*/i.test(line)) {
      const name = /ngc=([^\s]+)/i.exec(line)?.[1];
      if (name) { const candidate = normalize(`${dirname(source)}/remap_subs/${name}.ngc`); if (candidate) references.push({ path: candidate, key: "REMAP", section, source }); }
      continue;
    }
    const assignment = line.match(/^([^=:#]+?)\s*(?:=|:)\s*(.*)$/);
    if (assignment && RESOURCE_KEYS.has(assignment[1].trim().toUpperCase())) {
      const key = assignment[1].trim().toUpperCase();
      const values = tokens(assignment[2]);
      const resourceValues = key === "PROGRAMS" ? values : values.slice(0, 1);
      for (const value of resourceValues) references.push(...candidates(source, value, key, section).map((path) => ({ path, key, section, source })));
      continue;
    }
    const halSource = line.match(/^source\s+(.+)$/i);
    if (halSource && !halSource[1].trim().startsWith("[")) references.push(...candidates(source, halSource[1], "HAL", section).map((path) => ({ path, key: "HAL", section, source })));
    const halUser = line.match(/^loadusr\s+(?:-\S+\s+)*(.*)$/i);
    if (halUser && source === "linuxcnc/configs/sim/axis/vismach/3axis-tutorial/3axis-tutorial.hal") {
      const program = tokens(halUser[1])[0] ?? "";
      if (["./3axis-tutorial", "3axis-tutorial"].includes(program)) {
        references.push(...candidates(source, program, "PYTHON", section).map((path) => ({ path, key: "PYTHON", section, source, capability: "WEB-EQUIV" })));
      }
    }
  }
  return references;
}

export function findSimulationCase(path) {
  const registered = machineDefinition(path);
  return SIM_CASE_CATALOG.find((entry) => entry.path === path) ?? (registered ? { path: registered.entrypoint, coordinates: registered.coordinates, label: registered.label, status: "registered" } : null);
}

export async function loadSimulationCase({ path, fetchImpl = globalThis.fetch, baseUrl = "" } = {}) {
  if (typeof fetchImpl !== "function") throw new Error("simulation_case_fetch_required");
  const catalog = findSimulationCase(path);
  if (!catalog) throw new Error("simulation_case_unknown");
  const files = {};
  const fetched = [];
  const missing = [];
  const optionalMissing = [];
  const generatedResources = new Map();
  const runtimeFixtures = [];
  const queue = [catalog.path];
  const queued = new Set(queue);
  while (queue.length) {
    const current = queue.shift();
    const generated = generatedResources.get(current);
    const content = generated ? generated.content : await fetchText(fetchImpl, baseUrl, current);
    if (content === null) { missing.push(current); continue; }
    files[current] = content;
    fetched.push(current);
    for (const reference of resourceReferences(current, content)) {
      const candidate = reference.path;
      if (!inManifest(candidate)) {
        const generated = runtimeResourceKey(reference.key) ? generatedResource(candidate, reference.key) : null;
        if (generated) {
          if (!generatedResources.has(candidate)) {
            generatedResources.set(candidate, generated);
            files[candidate] = generated.content;
            fetched.push(candidate);
            runtimeFixtures.push({ case_path: catalog.path, resource_path: candidate, key: reference.key, kind: generated.kind, reason: generated.reason, data_hash: generated.data_hash });
          }
        } else if (isOptionalSourceKey(reference.key, reference.section)) {
          optionalMissing.push({ path: candidate, key: reference.key, section: reference.section ?? null, source: reference.source ?? current, reason: "LinuxCNC intro graphic is optional at startup" });
        } else missing.push(candidate);
        continue;
      }
      if (queued.has(candidate)) continue;
      queued.add(candidate);
      queue.push(candidate);
    }
  }
  // The XYZAC Vismach executable is the authoritative geometry contract for
  // the Web renderer. It is not referenced as a normal INI resource, so
  // resolve it explicitly and carry it through the Worker configuration for
  // source hashing and model provenance.
  const machine = machineDefinition(catalog.path);
  if (machine) {
    const programPath = machine.program;
    if (!(programPath in files)) {
      const content = await fetchText(fetchImpl, baseUrl, programPath);
      if (content === null) missing.push(programPath);
      else { files[programPath] = content; fetched.push(programPath); }
    }
    const visualSource = machine.source_path;
    if (!(visualSource in files)) {
      const content = await fetchText(fetchImpl, baseUrl, visualSource);
      if (content === null) missing.push(visualSource);
      else { files[visualSource] = content; fetched.push(visualSource); }
    }
  }
  const sourceIni = files[catalog.path];
  const fixture = RUNTIME_FIXTURES[catalog.path] ?? RUNTIME_FIXTURES[machine?.runtime_fixture];
  if (fixture) {
    if (!inManifest(fixture.generated_hal)) missing.push(fixture.generated_hal);
    else if (!files[fixture.generated_hal]) {
      const generated = await fetchText(fetchImpl, baseUrl, fixture.generated_hal);
      if (generated === null) missing.push(fixture.generated_hal);
      else { files[fixture.generated_hal] = generated; fetched.push(fixture.generated_hal); }
    }
    const targetPath = Object.keys(files).find((path) => files[path].includes(fixture.replace));
    const original = targetPath ? files[targetPath] : null;
    if (original && files[fixture.generated_hal]) {
      files[targetPath] = original.replace(fixture.replace, fixture.with);
      runtimeFixtures.push({ case_path: catalog.path, config_path: targetPath, generated_hal: fixture.generated_hal, reason: fixture.reason });
    }
  }
  const unsigned = {
    schema: SIMULATION_CASE_SCHEMA,
    entrypoint: catalog.path,
    files,
    fetched: [...fetched].sort(),
    missing: [...new Set(missing)].sort(),
    optional_missing: [...new Map(optionalMissing.map((row) => [`${row.source}:${row.path}:${row.key}`, row])).values()].sort((left, right) => JSON.stringify(left).localeCompare(JSON.stringify(right))),
    runtime_fixtures: runtimeFixtures,
  };
  return {
    ...clone(unsigned),
    source_ini: sourceIni,
    catalog,
    halManifest: [...new Set([...SIM_HAL_COMPONENTS, ...PRELOADED_HAL_COMPONENTS])].sort().map((component) => ({ component })),
    status: missing.length ? "blocked" : "ready",
    state_hash: fnv1a64(unsigned),
  };
}

export function toWorkerConfiguration(bundle) {
  if (!bundle || bundle.schema !== SIMULATION_CASE_SCHEMA) throw new Error("simulation_case_bundle_invalid");
  const kinematics = CASE_KINEMATICS[bundle.entrypoint] ? clone(CASE_KINEMATICS[bundle.entrypoint]) : null;
  const trt = machineDefinition(bundle.entrypoint) ? readTrtConfiguration(bundle) : null;
  let homeLimits = null;
  if (!trt) {
    const parsed = parseIni({ workspace: new WorkspaceRuntime({ files: bundle.files }), entrypoint: bundle.entrypoint });
    const coordinates = parsed.sections.TRAJ?.COORDINATES?.replace(/\s/g, "").toUpperCase();
    if (coordinates && /^[XYZABCUVW]+$/.test(coordinates)) {
      const limits = {};
      for (const [index, axis] of [...coordinates].entries()) {
        const section = parsed.sections[`JOINT_${index}`] ?? parsed.sections[`AXIS_${axis}`];
        if (!section || section.MIN_LIMIT === undefined || section.MAX_LIMIT === undefined) continue;
        const range = [Number(section.MIN_LIMIT), Number(section.MAX_LIMIT)];
        if (!range.every(Number.isFinite) || range[0] >= range[1]) throw new Error(`configuration_joint_limits:${index}`);
        limits[axis.toLowerCase()] = range;
      }
      if (Object.keys(limits).length) homeLimits = { coordinates, joint_count: coordinates.length, ...limits };
    }
  }
  return {
    entrypoint: bundle.entrypoint,
    files: clone(bundle.files),
    halManifest: clone(bundle.halManifest ?? []),
    state_hash: bundle.state_hash,
    optional_missing: clone(bundle.optional_missing ?? []),
    runtime_fixtures: clone(bundle.runtime_fixtures ?? []),
    ...(homeLimits ? { home_limits: homeLimits } : {}),
    ...(trt ?? (kinematics ? { kinematics } : {})),
  };
}

export { CASE_KINEMATICS, PRELOADED_HAL_COMPONENTS, RESOURCE_KEYS, RUNTIME_FIXTURES };