/**
 * @file report/builder.ts
 * Compiles the final Markdown report: synthesis, contradictions, coverage,
 * sources, citation index, and run diagnostics.
 */
import type {
  CompiledReport, ContradictionEntry, CrawledSource, DepthProfile, StatusFn,
} from "../core/types";
import { RunLedger, renderDiagnostics } from "../core/ledger";
import { detectCoveredDimensions, detectGapDimensions, DIMENSIONS } from "../core/dimensions";
import { extractKeywords, truncate } from "../core/util";
import { synthesiseReport, detectContradictions } from "../synthesis/ai";

function labelOf(id: string): string {
  return DIMENSIONS.find((d) => d.id === id)?.label ?? id;
}


export async function buildReport(
  topic: string,
  sources: ReadonlyArray<CrawledSource>,
  queriesUsed: ReadonlyArray<string>,
  ledger: RunLedger,
  usedAI: boolean,
  enableAI: boolean,
  profile: DepthProfile,
  status: StatusFn,
  learnings: ReadonlyArray<string> = [],
  abortSignal?: AbortSignal,
  partialNotice?: string,
): Promise<CompiledReport> {
  const indexed = sources.map((s, i) => ({ ...s, index: i + 1 }));
  const keywords = extractKeywords(topic);
  const coveredIds = detectCoveredDimensions(indexed.map((s) => s.text));
  const gapIds = detectGapDimensions(coveredIds).map((d) => d.id);

  let aiSynthesis: string | null = null;
  let contradictions: ReadonlyArray<ContradictionEntry> = [];
  const aiActive = enableAI && indexed.length > 0 && !(abortSignal?.aborted ?? false);
  if (aiActive) {
    const coveredLabels = coveredIds.map(labelOf);
    const gapLabels = gapIds.map(labelOf);

    const [synthesisResult, contradictionResult] = await Promise.all([
      synthesiseReport(topic, indexed, coveredLabels, gapLabels, status, profile, learnings, abortSignal)
        .catch(() => null),
      detectContradictions(topic, indexed, status, profile, abortSignal)
        .catch(() => [] as ContradictionEntry[]),
    ]);
    aiSynthesis = synthesisResult;
    contradictions = contradictionResult;
  }

  const sections: string[] = [buildHeader(topic, indexed.length, usedAI, coveredIds.length)];
  if (partialNotice !== undefined && partialNotice.length > 0) {
    sections.push(partialNotice, "---");
  }
  sections.push("---");

  if (aiSynthesis !== null) sections.push(`## Research Analysis\n\n${aiSynthesis}`, "---");

  if (learnings.length > 0 && aiSynthesis === null) {
    sections.push(
      "## Key Learnings\n\n" +
      learnings.map((l) => `- ${l}`).join("\n"),
      "---",
    );
  }
  if (contradictions.length > 0) sections.push(buildContradictionSection(contradictions), "---");

  sections.push(
    buildCoverageSection(coveredIds),
    "---",
    buildSourcesSection(indexed),
    "---",
    renderDiagnostics(ledger.snapshot(totalBudgetOf(profile), ledger.fetched)),
    "---",
    `*Generated by DeepResearch v2 · ${indexed.length} sources · ${queriesUsed.length} queries · Verify important claims against primary sources.*`,
  );

  return {
    markdown: sections.join("\n\n"),
    sources: indexed,
    coveredDims: coveredIds,
    gapDims: gapIds,
    aiSynthesis: aiSynthesis ?? undefined,
    contradictions,
  };
}

function totalBudgetOf(_profile: DepthProfile): number {
  // The orchestrator records actual fetches; budget ceiling is informational.
  return _profile.pagesPerCrawlerRound * Math.max(3, _profile.crawlerCount);
}

function buildHeader(
  topic: string,
  sourceCount: number,
  usedAI: boolean,
  coverageCount: number,
): string {
  return [
    `# Research Report: ${topic}`,
    "",
    `- **Generated:** ${new Date().toUTCString()}`,
    `- **Sources:** ${sourceCount}`,
    `- **Dimensions covered:** ${coverageCount}/12`,
    `- **Planning:** ${usedAI ? "AI-decomposed" : "template-based"}`,
  ].join("\n");
}

function buildContradictionSection(entries: ReadonlyArray<ContradictionEntry>): string {
  const lines = ["## Contradictions Detected", ""];
  for (const entry of entries) {
    lines.push(
      `### ${entry.claim}`,
      `- **[${entry.sourceA.index}] ${entry.sourceA.title}**: ${entry.sourceA.stance}`,
      `- **[${entry.sourceB.index}] ${entry.sourceB.title}**: ${entry.sourceB.stance}`,
      `- Severity: \`${entry.severity}\``,
      "",
    );
  }
  return lines.join("\n");
}

function buildCoverageSection(coveredIds: ReadonlyArray<string>): string {
  const covered = new Set(coveredIds);
  const rows = DIMENSIONS.map((dim) =>
    `| ${covered.has(dim.id) ? "yes" : "—"} | ${dim.label} |`).join("\n");
  return ["## Dimension Coverage", "", "| Covered | Dimension |", "|---|---|", rows].join("\n");
}

function buildSourcesSection(sources: ReadonlyArray<CrawledSource>): string {
  const lines = ["## Sources", ""];
  for (const s of sources) {
    const originTag = s.origin === "local" ? " `[local]`" : "";
    const pub = s.published !== null ? ` (${s.published})` : "";
    lines.push(
      `**[${s.index}]** [${truncate(s.title, 110)}](${s.url})${pub}${originTag}`,
      `> rel=${s.relevanceScore.toFixed(2)} · tier=${s.tier} · authority=${s.authorityScore} · ${s.wordCount} words · via ${s.engine}`,
      `> ${truncate(s.description.replace(/\n+/g, " "), 200)}`,
      "",
    );
  }
  return lines.join("\n");
}

/**
 * @file report/builder.ts
 * Compiles the final Markdown report: synthesis, contradictions, coverage,
 * sources, citation index, and run diagnostics.
 */
import type {
  CompiledReport, ContradictionEntry, CrawledSource, DepthProfile, StatusFn,
} from "../core/types";
import { RunLedger, renderDiagnostics } from "../core/ledger";
import { detectCoveredDimensions, detectGapDimensions, DIMENSIONS } from "../core/dimensions";
import { extractKeywords, truncate } from "../core/util";
import { synthesiseReport, detectContradictions } from "../synthesis/ai";

function labelOf(id: string): string {
  return DIMENSIONS.find((d) => d.id === id)?.label ?? id;
}


export async function buildReport(
  topic: string,
  sources: ReadonlyArray<CrawledSource>,
  queriesUsed: ReadonlyArray<string>,
  ledger: RunLedger,
  usedAI: boolean,
  enableAI: boolean,
  profile: DepthProfile,
  status: StatusFn,
  learnings: ReadonlyArray<string> = [],
  abortSignal?: AbortSignal,
  partialNotice?: string,
): Promise<CompiledReport> {
  const indexed = sources.map((s, i) => ({ ...s, index: i + 1 }));
  const keywords = extractKeywords(topic);
  const coveredIds = detectCoveredDimensions(indexed.map((s) => s.text));
  const gapIds = detectGapDimensions(coveredIds).map((d) => d.id);

  let aiSynthesis: string | null = null;
  let contradictions: ReadonlyArray<ContradictionEntry> = [];
  const aiActive = enableAI && indexed.length > 0 && !(abortSignal?.aborted ?? false);
  if (aiActive) {
    const coveredLabels = coveredIds.map(labelOf);
    const gapLabels = gapIds.map(labelOf);

    const [synthesisResult, contradictionResult] = await Promise.all([
      synthesiseReport(topic, indexed, coveredLabels, gapLabels, status, profile, learnings, abortSignal)
        .catch(() => null),
      detectContradictions(topic, indexed, status, profile, abortSignal)
        .catch(() => [] as ContradictionEntry[]),
    ]);
    aiSynthesis = synthesisResult;
    contradictions = contradictionResult;
  }

  const sections: string[] = [buildHeader(topic, indexed.length, usedAI, coveredIds.length)];
  if (partialNotice !== undefined && partialNotice.length > 0) {
    sections.push(partialNotice, "---");
  }
  sections.push("---");

  if (aiSynthesis !== null) sections.push(`## Research Analysis\n\n${aiSynthesis}`, "---");

  if (learnings.length > 0 && aiSynthesis === null) {
    sections.push(
      "## Key Learnings\n\n" +
      learnings.map((l) => `- ${l}`).join("\n"),
      "---",
    );
  }
  if (contradictions.length > 0) sections.push(buildContradictionSection(contradictions), "---");

  sections.push(
    buildCoverageSection(coveredIds),
    "---",
    buildSourcesSection(indexed),
    "---",
    renderDiagnostics(ledger.snapshot(totalBudgetOf(profile), ledger.fetched)),
    "---",
    `*Generated by DeepResearch v2 · ${indexed.length} sources · ${queriesUsed.length} queries · Verify important claims against primary sources.*`,
  );

  return {
    markdown: sections.join("\n\n"),
    sources: indexed,
    coveredDims: coveredIds,
    gapDims: gapIds,
    aiSynthesis: aiSynthesis ?? undefined,
    contradictions,
  };
}

function totalBudgetOf(_profile: DepthProfile): number {
  // The orchestrator records actual fetches; budget ceiling is informational.
  return _profile.pagesPerCrawlerRound * Math.max(3, _profile.crawlerCount);
}

function buildHeader(
  topic: string,
  sourceCount: number,
  usedAI: boolean,
  coverageCount: number,
): string {
  return [
    `# Research Report: ${topic}`,
    "",
    `- **Generated:** ${new Date().toUTCString()}`,
    `- **Sources:** ${sourceCount}`,
    `- **Dimensions covered:** ${coverageCount}/12`,
    `- **Planning:** ${usedAI ? "AI-decomposed" : "template-based"}`,
  ].join("\n");
}

function buildContradictionSection(entries: ReadonlyArray<ContradictionEntry>): string {
  const lines = ["## Contradictions Detected", ""];
  for (const entry of entries) {
    lines.push(
      `### ${entry.claim}`,
      `- **[${entry.sourceA.index}] ${entry.sourceA.title}**: ${entry.sourceA.stance}`,
      `- **[${entry.sourceB.index}] ${entry.sourceB.title}**: ${entry.sourceB.stance}`,
      `- Severity: \`${entry.severity}\``,
      "",
    );
  }
  return lines.join("\n");
}

function buildCoverageSection(coveredIds: ReadonlyArray<string>): string {
  const covered = new Set(coveredIds);
  const rows = DIMENSIONS.map((dim) =>
    `| ${covered.has(dim.id) ? "yes" : "—"} | ${dim.label} |`).join("\n");
  return ["## Dimension Coverage", "", "| Covered | Dimension |", "|---|---|", rows].join("\n");
}

function buildSourcesSection(sources: ReadonlyArray<CrawledSource>): string {
  const lines = ["## Sources", ""];
  for (const s of sources) {
    const originTag = s.origin === "local" ? " `[local]`" : "";
    const pub = s.published !== null ? ` (${s.published})` : "";
    lines.push(
      `**[${s.index}]** [${truncate(s.title, 110)}](${s.url})${pub}${originTag}`,
      `> rel=${s.relevanceScore.toFixed(2)} · tier=${s.tier} · authority=${s.authorityScore} · ${s.wordCount} words · via ${s.engine}`,
      `> ${truncate(s.description.replace(/\n+/g, " "), 200)}`,
      "",
    );
  }
  return lines.join("\n");
}