/**
 * `tailwind/arbitrary-color` — flags color-bearing Tailwind utilities with
 * arbitrary raw color values, e.g. `bg-[#abc123]` or
 * `text-[rgb(10,20,30)]`.
 */

import type { FactIndex, TailwindClassFact } from "../facts/index.js";

import { makeFinding } from "./finding.js";
import type { Finding } from "./types.js";
import { detectRawColor, isExemptColor, readUsageNode } from "./utils.js";

export const RULE_ID = "tailwind/arbitrary-color";
export const RULE_VERSION = "1";

const COLOR_UTILITIES = new Set([
  "accent",
  "bg",
  "border",
  "border-b",
  "border-e",
  "border-l",
  "border-r",
  "border-s",
  "border-t",
  "border-x",
  "border-y",
  "caret",
  "decoration",
  "divide",
  "fill",
  "from",
  "outline",
  "placeholder",
  "ring",
  "ring-offset",
  "shadow",
  "stroke",
  "text",
  "to",
  "via",
]);

export function ruleTailwindArbitraryColor(ix: FactIndex): Finding[] {
  const policy = ix.policy.rawColorPolicy();
  if (!policy) return [];

  const findings: Finding[] = [];
  for (const klass of ix.byKind("tailwind_class")) {
    if (klass.value.kind !== "arbitrary") continue;
    if (!COLOR_UTILITIES.has(klass.utility)) continue;

    const color = detectRawColor(klass.value.raw);
    if (!color) continue;
    if (isExemptColor(color, policy.except)) continue;

    const node = readUsageNode(ix, klass.nodeId);
    const evidenceIds = node ? [node.id, klass.id, policy.id] : [klass.id, policy.id];

    findings.push(
      makeFinding({
        ruleId: RULE_ID,
        ruleVersion: RULE_VERSION,
        severity: policy.severity,
        message: `\`${klass.raw}\` uses arbitrary raw color ${color}. Use a ${policy.prefer === "token" ? "design token" : "CSS variable"} instead.`,
        location: klass.location,
        evidence: ix.evidence(evidenceIds),
        fingerprintIdentity: fingerprintIdentity(klass, color),
        attributes: {
          rawClass: klass.raw,
          rawValue: klass.value.raw,
          color,
          utility: klass.utility,
          source: "tailwind",
        },
      }),
    );
  }

  return findings;
}

function fingerprintIdentity(klass: TailwindClassFact, color: string): Record<string, unknown> {
  return {
    source: "tailwind_class",
    file: klass.file,
    nodeId: klass.nodeId,
    originPath: klass.originPath,
    raw: klass.raw,
    utility: klass.utility,
    value: color,
  };
}