import type { ProblemSpec } from "../spec/types";
import type { MethodDefinition } from "../methods/types";
import { generateParamsBlock } from "./params";
import { LIBRARY_FILES, type SourceFile } from "./library";

/** A complete, self-contained set of `.m` files plus the one to run. */
export interface SourceBundle {
  files: SourceFile[];
  /** File executed as the script */
  entry: string;
  /** Workspace variable read back after the run */
  resultVariable: string;
}

export const MAIN_FILE = "main.m";

/** The script a method runs: the params block followed by the solver call. */
export function generateMain(spec: ProblemSpec, method: MethodDefinition): string {
  return [
    generateParamsBlock(spec),
    "",
    `% Solve.  ${method.solverFunction} and the functions it calls are the library files in the other tabs.`,
    `result = ${method.solverFunction}(params);`,
    "",
  ].join("\n");
}

/** Bundle for running one method on a spec. */
export function buildRunBundle(spec: ProblemSpec, method: MethodDefinition): SourceBundle {
  return {
    files: [{ name: MAIN_FILE, source: generateMain(spec, method) }, ...LIBRARY_FILES],
    entry: MAIN_FILE,
    resultVariable: "result",
  };
}

/** Bundle that evaluates a method's cost plan (currently only the FD method has one). */
export function buildPlanBundle(spec: ProblemSpec, method: MethodDefinition): SourceBundle | null {
  if (!method.planFunction) return null;
  const main = [generateParamsBlock(spec), "", `plan = ${method.planFunction}(params);`, ""].join("\n");
  return {
    files: [{ name: "plan.m", source: main }, ...LIBRARY_FILES],
    entry: "plan.m",
    resultVariable: "plan",
  };
}

/** Bundle comparing two results, which the runner passes in as workspace variables A and B. */
export function buildCompareBundle(): SourceBundle {
  const main = [
    "% A and B are two result structs for the same problem (A: modal, B: finite differences).",
    "cmp = plate_compare(A, B);",
    "",
  ].join("\n");
  return {
    files: [{ name: "compare.m", source: main }, ...LIBRARY_FILES],
    entry: "compare.m",
    resultVariable: "cmp",
  };
}

/**
 * Replace files in a bundle with edited versions, keeping everything else. Used
 * when the user edits source in the code view: the run then uses exactly the
 * text on screen.
 */
export function withEdits(bundle: SourceBundle, edits: Record<string, string>): SourceBundle {
  return {
    ...bundle,
    files: bundle.files.map((f) => (edits[f.name] !== undefined ? { ...f, source: edits[f.name] } : f)),
  };
}