/**
 * Section content generators for lexicon documentation pages.
 *
 * Each function produces a complete MDX page string with frontmatter.
 */

import { escapeMdx } from "./docs-file-markers";
import { intrinsicFolds } from "../lexicon";
import type { DocsConfig, ManifestJSON, MetaEntry, RuleMeta } from "./docs-types";

export function generateOverview(
  config: DocsConfig,
  manifest: ManifestJSON,
  resources: Map<string, MetaEntry>,
  properties: Map<string, MetaEntry>,
  serviceGroups: Map<string, Map<string, MetaEntry>>,
  rules: RuleMeta[],
): string {
  const lines: string[] = [
    "---",
    `title: "${config.displayName}"`,
    `description: "${config.description}"`,
    "---",
    "",
    config.overview ?? `Reference documentation for the **${config.displayName}** lexicon.`,
    "",
    "## At a Glance",
    "",
    `| Metric | Count |`,
    `|--------|-------|`,
    `| Resources | ${resources.size} |`,
    `| Property types | ${properties.size} |`,
    `| Services | ${serviceGroups.size} |`,
    `| Intrinsic functions | ${manifest.intrinsics?.length ?? 0} |`,
    `| Pseudo-parameters | ${Object.keys(manifest.pseudoParameters ?? {}).length} |`,
    `| Lint rules | ${rules.length} |`,
    "",
    `**Lexicon version:** ${manifest.version}  `,
    `**Namespace:** \`${manifest.namespace ?? manifest.name}\``,
    "",
  ];

  const suppress = new Set(config.suppressPages ?? []);

  if (!suppress.has("intrinsics") && manifest.intrinsics && manifest.intrinsics.length > 0) {
    lines.push(
      `- [Intrinsic Functions](./intrinsics) — ${manifest.intrinsics.length} built-in functions`,
    );
  }
  if (
    !suppress.has("pseudo-parameters") &&
    manifest.pseudoParameters &&
    Object.keys(manifest.pseudoParameters).length > 0
  ) {
    lines.push(
      `- [Pseudo-Parameters](./pseudo-parameters) — ${Object.keys(manifest.pseudoParameters).length} pseudo-parameters`,
    );
  }
  // Same reasoning as the sidebar's rules entry: link the complete table on
  // every lexicon, under the label the sidebar uses, whether or not a prose
  // `lint-rules` page also exists.
  if (!suppress.has("rules") && rules.length > 0) {
    lines.push(`- [All Rules](./rules) — ${rules.length} rules`);
  }
  if (!suppress.has("serialization")) {
    lines.push(`- [Serialization](./serialization) — output format details`);
  }

  if (config.extraSections) {
    for (const section of config.extraSections) {
      lines.push("", `## ${section.title}`, "", section.content);
    }
  }

  lines.push("");
  return lines.join("\n");
}

export function generateIntrinsics(
  config: DocsConfig,
  manifest: ManifestJSON,
): string {
  const intrinsics = manifest.intrinsics!;
  const lines: string[] = [
    "---",
    `title: "Intrinsic Functions"`,
    `description: "Built-in intrinsic functions for the ${config.displayName} lexicon"`,
    "---",
    "",
    `The ${config.displayName} lexicon provides **${intrinsics.length}** intrinsic functions.`,
    "",
    `**Tag?** shows how an intrinsic is authored: a genuine tagged template (\`Sub\\\`...\\\`\`) or a plain function call (\`Ref(...)\`). **Folds?** shows whether [folding](/chant/concepts/typescript-as-data/#folded-vs-run) — the default \`chant build\` path — can reduce a use of this intrinsic today, without running the file — generated directly from this lexicon's registration, not restated by hand. A tagged template folds once it is registered. A plain call folds only where this lexicon has opted that intrinsic in one at a time (\`foldsAsCall\`), so a \`No\` in this column means this intrinsic has not been opted in, not that calls in general cannot fold.`,
    "",
    "| Function | Description | Output Key | Tag? | Folds? |",
    "|----------|-------------|------------|------|--------|",
  ];

  for (const fn of intrinsics) {
    const tag = fn.isTag ? "Yes" : "No";
    const folds = intrinsicFolds(fn) ? "Yes" : "No";
    lines.push(
      `| \`${fn.name}\` | ${escapeMdx(fn.description ?? "—")} | \`${fn.outputKey ?? fn.name}\` | ${tag} | ${folds} |`,
    );
  }

  lines.push("");
  return lines.join("\n");
}

export function generatePseudoParameters(
  config: DocsConfig,
  manifest: ManifestJSON,
): string {
  const params = manifest.pseudoParameters!;
  const entries = Object.entries(params);
  const lines: string[] = [
    "---",
    `title: "Pseudo-Parameters"`,
    `description: "Pseudo-parameters available in the ${config.displayName} lexicon"`,
    "---",
    "",
    `The ${config.displayName} lexicon provides **${entries.length}** pseudo-parameters — predefined values available in every stack without explicit declaration.`,
    "",
    "| Name | Value |",
    "|------|-------|",
  ];

  for (const [name, value] of entries) {
    lines.push(`| \`${name}\` | \`${value}\` |`);
  }

  lines.push("");
  return lines.join("\n");
}

export function generateSerialization(config: DocsConfig): string {
  const lines: string[] = [
    "---",
    `title: "Serialization"`,
    `description: "Output format for the ${config.displayName} lexicon"`,
    "---",
    "",
  ];

  if (config.outputFormat) {
    lines.push(config.outputFormat);
  } else {
    lines.push(
      `The ${config.displayName} lexicon serializes resources into its native output format during the build step.`,
      "",
      "See the [Serialization](/chant/serialization/output-formats) guide for general information about output formats in chant.",
    );
  }

  lines.push("");
  return lines.join("\n");
}