import type { ProjectFile } from "./project";
import { flattenKeys } from "./geometry";
import type { Node } from "./phy";
import { eligibleKeyIds, unregisteredKeys } from "./idx";
import { parseKeycode } from "./map";
import { validateSchema } from "../io/validateSchema";
export type ValidationIssue = {
  severity: "blocksSave" | "blocksOutput" | "warning";
  code: string;
  message: string;
  path?: string;
  ids?: string[];
};
/** Performs semantic validation of a complete mock project. T-13/T-16/T-21/T-25. */
export function validateProject(p: ProjectFile): ValidationIssue[] {
  const out: ValidationIssue[] = [];
  for (const layer of ["phy", "idx", "elc", "map"] as const)
    for (const e of validateSchema(layer, p[layer]))
      out.push({ severity: "blocksSave", code: "schema", message: e.message, path: `${layer}${e.path}` });
  if (p.format !== "beyond-kle-mock-project")
    out.push({
      severity: "blocksSave",
      code: "project-format",
      message: "Unsupported ProjectFile format",
      path: "/format",
    });
  if (p.version !== "0.1.0")
    out.push({
      severity: "blocksSave",
      code: "version",
      message: "Unsupported ProjectFile version",
      path: "/version",
    });
  for (const layer of ["phy", "idx", "elc", "map"] as const)
    if (p[layer].version !== "0.1.0")
      out.push({
        severity: "blocksSave",
        code: "version",
        message: `Unsupported ${layer} version`,
        path: `/${layer}/version`,
      });
  const ids = new Map<string, string[]>();
  const add = (id: string, path: string) => ids.set(id, [...(ids.get(id) ?? []), path]);
  const walk = (ns: Node[], path: string) =>
    ns.forEach((n, i) => {
      const q = `${path}/${i}`;
      add(n.id, q);
      if (n.type === "cluster") walk(n.children, q + "/children");
      if (n.type === "variantGroup") {
        if (!n.children.some((v) => v.id === n.default))
          out.push({
            severity: "blocksSave",
            code: "missing-default-variant",
            message: "VariantGroup default does not reference a child",
            path: q + "/default",
            ids: [n.id, n.default],
          });
        for (const v of n.children) {
          add(v.id, q + "/children");
          walk(v.children, q + `/children/${v.id}/children`);
        }
      }
    });
  walk(p.phy.root, "/phy/root");
  for (const [id, paths] of ids)
    if (paths.length > 1)
      out.push({
        severity: "blocksSave",
        code: "duplicate-id",
        message: "Duplicate PHY node ID",
        ids: [id],
        path: paths[1],
      });
  const nodes = new Set(ids.keys()),
    keys = new Set(eligibleKeyIds(p.phy));
  const ref = (id: string, path: string, valid: Set<string> = nodes) => {
    if (!valid.has(id))
      out.push({
        severity: "blocksSave",
        code: "missing-reference",
        message: `Unknown reference: ${id}`,
        path,
        ids: [id],
      });
  };
  p.idx.order.forEach((id, i) => ref(id, `/idx/order/${i}`, keys));
  p.elc.keys.forEach((k, i) => ref(k.key, `/elc/keys/${i}/key`, keys));
  p.elc.ledChains?.forEach((c, i) => c.order.forEach((id, j) => ref(id, `/elc/ledChains/${i}/order/${j}`)));
  p.map.layers.forEach((l, i) =>
    l.keymap.forEach((a, j) => {
      ref(a.keyId, `/map/layers/${i}/keymap/${j}/keyId`, keys);
      const keycode = parseKeycode(a.keycode);
      if (keycode.kind === "layer" && !p.map.layers.some((candidate) => candidate.name === keycode.layer))
        out.push({
          severity: "blocksSave",
          code: "missing-map-layer-reference",
          message: `Unknown MAP layer reference: ${keycode.layer}`,
          path: `/map/layers/${i}/keymap/${j}/keycode`,
          ids: [l.name, keycode.layer ?? ""],
        });
    }),
  );

  const providerIds = new Map<string, number>();
  p.elc.providers.forEach((provider, index) => {
    const first = providerIds.get(provider.id);
    if (first !== undefined)
      out.push({
        severity: "blocksSave",
        code: "duplicate-provider-id",
        message: "Provider IDs must be unique",
        path: `/elc/providers/${index}/id`,
        ids: [provider.id],
      });
    else providerIds.set(provider.id, index);
    if (!provider.id || provider.id.includes("."))
      out.push({
        severity: "blocksSave",
        code: "invalid-provider-id",
        message: "Provider IDs must be nonempty and cannot contain '.'",
        path: `/elc/providers/${index}/id`,
        ids: [provider.id],
      });
  });
  const chainIds = new Set<string>();
  p.elc.ledChains?.forEach((chain, index) => {
    if (chainIds.has(chain.id))
      out.push({
        severity: "blocksSave",
        code: "duplicate-led-chain-id",
        message: "LED chain IDs must be unique",
        path: `/elc/ledChains/${index}/id`,
        ids: [chain.id],
      });
    chainIds.add(chain.id);
  });
  const wiredKeys = new Set<string>();
  p.elc.keys.forEach((wiring, index) => {
    if (wiredKeys.has(wiring.key))
      out.push({
        severity: "blocksSave",
        code: "duplicate-key-wiring",
        message: "A key may have only one ELC wiring entry",
        path: `/elc/keys/${index}/key`,
        ids: [wiring.key],
      });
    wiredKeys.add(wiring.key);
  });

  const validatePinRef = (pin: string, path: string) => {
    if (pin === "VCC" || pin === "GND") return;
    const parts = pin.split(".");
    const providerId = parts[0];
    const pinName = parts[1];
    if (parts.length !== 2 || !providerId || !pinName) {
      out.push({
        severity: "blocksSave",
        code: "invalid-pin-reference",
        message: `Malformed PinRef: ${pin}`,
        path,
        ids: [pin],
      });
      return;
    }
    const provider = p.elc.providers.find((candidate) => candidate.id === providerId);
    if (!provider) {
      out.push({
        severity: "blocksSave",
        code: "missing-pin-provider",
        message: `Unknown PinRef provider: ${providerId}`,
        path,
        ids: [providerId, pin],
      });
      return;
    }
    let valid = true;
    if (provider.kind === "analog-mux")
      valid = /^(0|[1-9]\d*)$/.test(pinName) && Number(pinName) < provider.channels;
    else if (provider.part.toUpperCase() === "RP2040") valid = /^GP(?:[0-9]|[12][0-9])$/.test(pinName);
    if (!valid)
      out.push({
        severity: "blocksSave",
        code: "unknown-provider-pin",
        message: `Unknown pin ${pinName} on provider ${providerId}`,
        path,
        ids: [providerId, pinName],
      });
  };
  p.elc.providers.forEach((provider, index) => {
    if (provider.kind === "analog-mux") {
      provider.select.forEach((pin, i) => validatePinRef(pin, `/elc/providers/${index}/select/${i}`));
      validatePinRef(provider.common, `/elc/providers/${index}/common`);
      if (provider.enable !== undefined) validatePinRef(provider.enable, `/elc/providers/${index}/enable`);
    }
  });
  p.elc.keys.forEach((wiring, index) =>
    Object.entries(wiring.terminals).forEach(([terminal, pin]) =>
      validatePinRef(pin, `/elc/keys/${index}/terminals/${terminal}`),
    ),
  );
  p.elc.ledChains?.forEach((chain, index) => validatePinRef(chain.data, `/elc/ledChains/${index}/data`));
  p.output.matrix?.rowPins.forEach((pin, index) => validatePinRef(pin, `/output/matrix/rowPins/${index}`));
  p.output.matrix?.colPins.forEach((pin, index) => validatePinRef(pin, `/output/matrix/colPins/${index}`));
  const profileIds = new Set(p.phy.profiles.map((x) => x.id));
  const checkProfiles = (ns: Node[]) =>
    ns.forEach((n, i) => {
      if (n.type === "key" && !profileIds.has(n.profile))
        out.push({
          severity: "blocksSave",
          code: "missing-profile",
          message: `Unknown profile: ${n.profile}`,
          path: `/phy/key/${n.id}/profile`,
          ids: [n.id, n.profile],
        });
      if (n.type === "cluster") checkProfiles(n.children);
      if (n.type === "variantGroup") n.children.forEach((v) => checkProfiles(v.children));
    });
  checkProfiles(p.phy.root);
  for (const [i, pr] of p.phy.profiles.entries()) {
    if (pr.unitSize.x <= 0 || pr.unitSize.y <= 0)
      out.push({
        severity: "blocksSave",
        code: "positive-unit-size",
        message: "unitSize values must be positive",
        path: `/phy/profiles/${i}/unitSize`,
      });
  }
  const keyWalk = (ns: Node[]) =>
    ns.forEach((n) => {
      if (n.type === "key" && (n.size.w <= 0 || n.size.h <= 0))
        out.push({
          severity: "blocksSave",
          code: "positive-key-size",
          message: "Key size values must be positive",
          path: `/phy/key/${n.id}/size`,
          ids: [n.id],
        });
      if (n.type === "cluster") keyWalk(n.children);
      if (n.type === "variantGroup") n.children.forEach((v) => keyWalk(v.children));
    });
  keyWalk(p.phy.root);
  const unreg = unregisteredKeys(p.phy, p.idx);
  for (const id of unreg)
    out.push({
      severity: "blocksOutput",
      code: "idx-unregistered",
      message: "Eligible key is not in IDX order",
      ids: [id],
    });
  const profileSizes = p.phy.profiles.map((x) => `${x.unitSize.x},${x.unitSize.y}`);
  if (new Set(profileSizes).size > 1)
    out.push({
      severity: "warning",
      code: "unit-size-mismatch",
      message: "Profile unitSize values differ; geometry editing is restricted",
      path: "/phy/profiles",
    });
  let active: string[] = [];
  try {
    active = flattenKeys(p.phy, p.output.variantSelection)
      .filter((x) => !x.key.decal)
      .map((x) => x.key.id);
  } catch (e) {
    out.push({ severity: "blocksSave", code: "invalid-variant-selection", message: String(e) });
  }
  for (const id of active) {
    if (!p.elc.keys.some((k) => k.key === id))
      out.push({
        severity: "blocksOutput",
        code: "unwired-key",
        message: "Selected key has no wiring",
        ids: [id],
      });
    for (const l of p.map.layers)
      if (!l.keymap.some((a) => a.keyId === id))
        out.push({
          severity: "blocksOutput",
          code: "unassigned-key",
          message: `Selected key is not assigned in layer ${l.name}`,
          ids: [id, l.name],
        });
  }
  const branches = new Map<string, Array<[string, string]>>();
  const exclusivity = (ns: Node[], branch: Array<[string, string]>) =>
    ns.forEach((n) => {
      if (n.type === "key") branches.set(n.id, branch);
      if (n.type === "cluster") exclusivity(n.children, branch);
      if (n.type === "variantGroup")
        for (const v of n.children) exclusivity(v.children, [...branch, [n.id, v.id]]);
    });
  exclusivity(p.phy.root, []);
  const mutuallyExclusive = (a: string, b: string) => {
    for (const [group, variant] of branches.get(a) ?? [])
      if ((branches.get(b) ?? []).some(([g, v]) => g === group && v !== variant)) return true;
    return false;
  };
  const unordered = (a: string, b: string) => (a < b ? `${a}\0${b}` : `${b}\0${a}`);
  const contacts = p.elc.keys.filter((w) => w.detect === "contact");
  for (let i = 0; i < contacts.length; i++)
    for (let j = i + 1; j < contacts.length; j++) {
      const a = contacts[i]!,
        b = contacts[j]!;
      if (a.key === b.key || mutuallyExclusive(a.key, b.key)) continue;
      const ap = a.diode
        ? a.diode === "a-to-b"
          ? [a.terminals.a, a.terminals.b]
          : [a.terminals.b, a.terminals.a]
        : null;
      const bp = b.diode
        ? b.diode === "a-to-b"
          ? [b.terminals.a, b.terminals.b]
          : [b.terminals.b, b.terminals.a]
        : null;
      const same =
        ap && bp
          ? ap[0] === bp[0] && ap[1] === bp[1]
          : unordered(a.terminals.a, a.terminals.b) === unordered(b.terminals.a, b.terminals.b);
      if (same)
        out.push({
          severity: "blocksOutput",
          code: "wiring-collision",
          message: "Non-exclusive keys share the same electrical connection",
          ids: [a.key, b.key],
        });
    }
  const layerNames = new Set<string>();
  for (const [i, l] of p.map.layers.entries()) {
    if (layerNames.has(l.name))
      out.push({
        severity: "blocksSave",
        code: "duplicate-layer-name",
        message: "Layer names must be unique",
        path: `/map/layers/${i}/name`,
        ids: [l.name],
      });
    layerNames.add(l.name);
  }
  for (const [li, l] of p.map.layers.entries()) {
    const assignments = new Map<string, number>();
    for (const [ai, a] of l.keymap.entries()) {
      const prev = assignments.get(a.keyId);
      if (prev !== undefined)
        out.push({
          severity: "blocksSave",
          code: "duplicate-map-key",
          message: "A key may occur only once in a layer keymap",
          path: `/map/layers/${li}/keymap/${ai}/keyId`,
          ids: [a.keyId, l.name],
        });
      assignments.set(a.keyId, ai);
    }
  }
  return out;
}