// Known model corruptions for demonstrating the validator end-to-end.
//
// Each "break" returns a model variant that should fire one specific rule
// (or a small cluster) without firing others. Used by the editor's `?break=...`
// query param to make the validator's behavior visible.

import type { SysMLModel } from "./model";

export type BreakName =
  | "S1-dangling"
  | "S2-dangling-constraint"
  | "S3-untraced-satisfier"
  | "M2-cycle"
  | "M3-multi-system"
  | "M5-dup-property"
  | "T1-untraced-req"
  | "T2-unused-block";

export const BREAKS: Record<BreakName, { label: string; description: string; apply: (m: SysMLModel) => SysMLModel }> = {
  "S1-dangling": {
    label: "S1 — dangling association endpoint",
    description: "Add an association whose target block doesn't exist.",
    apply(m) {
      return {
        ...m,
        associations: [
          ...m.associations,
          { id: "a-bad", fromBlockId: "aristotle", toBlockId: "ghost-block", label: "haunts", kind: "association" },
        ],
      };
    },
  },

  "S2-dangling-constraint": {
    label: "S2 — constraint applies to unknown block",
    description: "Add a constraint pointing at a block that doesn't exist.",
    apply(m) {
      return {
        ...m,
        constraints: [
          ...m.constraints,
          { id: "c-bad", label: "Phantom rule", expression: "{}", appliesTo: ["ghost-block"] },
        ],
      };
    },
  },

  "S3-untraced-satisfier": {
    label: "S3 — requirement satisfied by unknown block",
    description: "Reroute REQ-001 to a non-existent block.",
    apply(m) {
      return {
        ...m,
        requirements: m.requirements.map(r =>
          r.tag === "REQ-001" ? { ...r, relations: [{ kind: "satisfy" as const, blockId: "ghost-block" }] } : r
        ),
      };
    },
  },

  "M2-cycle": {
    label: "M2 — cyclic composition",
    description: "Add a composition Assignment → Course (the inverse of the existing Course → Assignment).",
    apply(m) {
      return {
        ...m,
        associations: [
          ...m.associations,
          {
            id: "a-cycle",
            fromBlockId: "assignment",
            toBlockId: "course",
            label: "wraps",
            kind: "composition",
          },
        ],
      };
    },
  },

  "M3-multi-system": {
    label: "M3 — two System-of-Interest blocks",
    description: "Mark both Aristotle and Course as kind=system.",
    apply(m) {
      return {
        ...m,
        blocks: m.blocks.map(b =>
          b.id === "aristotle" || b.id === "course" ? { ...b, kind: "system" as const, stereotypes: ["system"] } : b
        ),
      };
    },
  },

  "M5-dup-property": {
    label: "M5 — duplicate property name in a block",
    description: "Add a second `interaction_style` property to Aristotle.",
    apply(m) {
      return {
        ...m,
        blocks: m.blocks.map(b =>
          b.id === "aristotle"
            ? {
                ...b,
                properties: [
                  ...b.properties,
                  { id: "p-dup", name: "interaction_style", type: { kind: "string" as const }, multiplicity: "0..1" as const },
                ],
              }
            : b
        ),
      };
    },
  },

  "T1-untraced-req": {
    label: "T1 — requirement with no satisfier",
    description: "Already present in the fixture (REQ-003 has no satisfy relation).",
    apply(m) {
      // No mutation needed; the fixture already triggers T1 on REQ-003.
      return m;
    },
  },

  "T2-unused-block": {
    label: "T2 — block with no incoming references",
    description: "Add a Tutor block that nothing connects to.",
    apply(m) {
      return {
        ...m,
        blocks: [
          ...m.blocks,
          {
            id: "tutor-orphan",
            label: "TutorOrphan",
            kind: "block",
            stereotypes: ["block"],
            properties: [],
          },
        ],
      };
    },
  },
};

export function applyBreaks(model: SysMLModel, names: BreakName[]): SysMLModel {
  return names.reduce((m, name) => BREAKS[name].apply(m), model);
}