export class StorageAuditReportApp extends foundry.applications.api.ApplicationV2 {
  static DEFAULT_OPTIONS = {
    id: "kosmos-storage-audit-report",
    classes: ["kosmos-storage-audit"],
    tag: "div",
    actions: {
      runAnalysis: StorageAuditReportApp.#onRunAnalysis,
      toggleShowAll: StorageAuditReportApp.#onToggleShowAll,
      toggleRaw: StorageAuditReportApp.#onToggleRaw,
      exportReport: StorageAuditReportApp.#onExportReport
    },
    window: {
      title: "Kosmos Storage Audit",
      icon: "fa-solid fa-broom-ball",
      resizable: true
    },
    position: {
      width: 980,
      height: 680
    }
  };

  #analysis = null;
  #loading = false;
  #showAll = false;
  #progress = null;
  #showRaw = false;

  constructor(options = {}) {
    super(options);
    this.options.window.title = localize("KSA.AppTitle");
  }

  async _prepareContext() {
    const findings = this.#analysis?.findings ?? [];
    const visibleFindings = this.#showAll ? findings : findings.filter(f => f.severity !== "info");
    const groupedFindings = groupFindings(visibleFindings);
    return {
      loading: this.#loading,
      hasAnalysis: !!this.#analysis,
      showAll: this.#showAll,
      showRaw: this.#showRaw,
      progress: this.#progress,
      summary: this.#summarize(this.#analysis),
      groupedFindings,
      findings: visibleFindings
    };
  }

  async _renderHTML(context) {
    const container = document.createElement("div");
    container.className = "storage-audit";
    container.innerHTML = `
      <section class="storage-audit__hero">
        <div>
          <h2>${localize("KSA.Hero.Title")}</h2>
          <p>${renderLocalizedCodeText("KSA.Hero.Intro1", { dataRoot: "data", publicRoot: "public" }, ["data", "public"])}</p>
          <p>${renderLocalizedCodeText("KSA.Hero.Intro2", { dataRoot: "data" }, ["data"])}</p>
          <p>${escapeHtml(localize("KSA.Hero.Intro3"))}</p>
        </div>
        <div class="storage-audit__actions">
          <button type="button" class="button" data-action="runAnalysis" ${context.loading ? "disabled" : ""}>
            <i class="fa-solid fa-magnifying-glass"></i>
            <span>${context.loading ? localize("KSA.Action.Running") : localize("KSA.Action.Run")}</span>
          </button>
          <button type="button" class="button" data-action="exportReport" ${context.hasAnalysis ? "" : "disabled"}>
            <i class="fa-solid fa-file-export"></i>
            <span>${localize("KSA.Action.Export")}</span>
          </button>
          <button type="button" class="button" data-action="toggleShowAll" ${context.hasAnalysis ? "" : "disabled"}>
            <i class="fa-solid fa-filter"></i>
            <span>${context.showAll ? localize("KSA.Action.ShowWarnings") : localize("KSA.Action.ShowAll")}</span>
          </button>
          <button type="button" class="button" data-action="toggleRaw" ${context.hasAnalysis ? "" : "disabled"}>
            <i class="fa-solid fa-list"></i>
            <span>${context.showRaw ? localize("KSA.Action.HideRaw") : localize("KSA.Action.ShowRaw")}</span>
          </button>
        </div>
      </section>
      ${renderProgress(context.progress, context.loading)}
      ${renderSummary(context.summary, context.loading)}
      ${renderGroupedFindingList(context.groupedFindings, context.hasAnalysis, context.loading, context.showAll)}
      ${renderFindingList(context.findings, context.hasAnalysis, context.loading, context.showAll, context.showRaw)}
    `;
    return container;
  }

  _replaceHTML(result, content) {
    content.replaceChildren(result);
    for (const link of content.querySelectorAll(".content-link[data-uuid]")) {
      link.addEventListener("click", event => {
        event.preventDefault();
        event.stopPropagation();
        void openSourceUuid(link.dataset.uuid);
      });
    }
  }

  async runAnalysis() {
    this.#loading = true;
    this.#progress = {
      phase: "start",
      label: localize("KSA.Progress.Initialize"),
      files: 0,
      sources: 0,
      references: 0,
      findings: 0,
      currentSource: null
    };
    await this.render({ force: true });
    try {
      const api = game.modules.get("kosmos-storage-audit")?.api;
      this.#analysis = await api.runRuntimeAnalysis({
        onProgress: update => this.#updateProgress(update)
      });
      const count = this.#analysis.findings.length;
      ui.notifications.info(format("KSA.Notify.Completed", { count }));
    } catch (error) {
      console.error("kosmos-storage-audit | analysis failed", error);
      ui.notifications.error(format("KSA.Notify.Failed", { message: error.message }));
    } finally {
      this.#loading = false;
      const currentWidth = this.position?.width ?? 0;
      if (currentWidth < 980) this.setPosition({ width: 980 });
      await this.render({ force: true });
    }
  }

  toggleShowAll() {
    this.#showAll = !this.#showAll;
    return this.render({ force: true });
  }

  toggleRaw() {
    this.#showRaw = !this.#showRaw;
    return this.render({ force: true });
  }

  exportReport() {
    if (!this.#analysis) return;
    const payload = {
      exportedAt: new Date().toISOString(),
      summary: this.#summarize(this.#analysis),
      groupedFindings: groupFindings(this.#analysis.findings),
      findings: this.#analysis.findings.map(serializeFinding)
    };
    const blob = new Blob([JSON.stringify(payload, null, 2)], { type: "application/json" });
    const url = URL.createObjectURL(blob);
    const link = document.createElement("a");
    link.href = url;
    link.download = format("KSA.Export.Filename", { timestamp: Date.now() });
    link.click();
    setTimeout(() => URL.revokeObjectURL(url), 0);
  }

  #summarize(analysis) {
    if (!analysis) return null;
    const bySeverity = { high: 0, warning: 0, info: 0 };
    const byKind = {};
    const grouped = {
      brokenReferences: 0,
      packageReferences: 0,
      orphans: 0
    };
    for (const finding of analysis.findings) {
      bySeverity[finding.severity] = (bySeverity[finding.severity] ?? 0) + 1;
      byKind[finding.kind] = (byKind[finding.kind] ?? 0) + 1;
    }
    grouped.brokenReferences = new Set(
      analysis.findings.filter(f => f.kind === "broken-reference").map(f => f.target.locator ?? formatTarget(f.target))
    ).size;
    grouped.packageReferences = new Set(
      analysis.findings.filter(f => f.kind === "non-package-to-package-reference").map(f => f.target.locator ?? formatTarget(f.target))
    ).size;
    grouped.orphans = analysis.findings.filter(f => f.kind === "orphan-file").length;
    return {
      files: analysis.files.length,
      references: analysis.references.length,
      findings: analysis.findings.length,
      bySeverity,
      byKind,
      grouped
    };
  }

  #updateProgress(update) {
    this.#progress = {
      ...(this.#progress ?? {}),
      ...update
    };
    this.render({ force: true });
  }

  static #onRunAnalysis(_event, _button) {
    return this.runAnalysis();
  }

  static #onToggleShowAll(_event, _button) {
    return this.toggleShowAll();
  }

  static #onToggleRaw(_event, _button) {
    return this.toggleRaw();
  }

  static #onExportReport(_event, _button) {
    return this.exportReport();
  }

}

function renderProgress(progress, loading) {
  if (!loading || !progress) return "";
  return `
    <section class="storage-audit__progress">
      <div class="storage-audit__progress-bar">
        <div class="storage-audit__progress-fill phase-${escapeHtml(progress.phase ?? "start")}"></div>
      </div>
      <div class="storage-audit__progress-meta">
        <strong>${escapeHtml(progress.label ?? localize("KSA.Progress.Analyzing"))}</strong>
        <span>${escapeHtml(format("KSA.Progress.Files", { count: progress.files ?? 0 }))}</span>
        <span>${escapeHtml(format("KSA.Progress.Sources", { count: progress.sources ?? 0 }))}</span>
        <span>${escapeHtml(format("KSA.Progress.References", { count: progress.references ?? 0 }))}</span>
        ${progress.findings != null ? `<span>${escapeHtml(format("KSA.Progress.Findings", { count: progress.findings }))}</span>` : ""}
      </div>
      ${progress.currentSource ? `<p class="storage-audit__progress-source">${escapeHtml(format("KSA.Progress.Current", { source: progress.currentSource }))}</p>` : ""}
    </section>
  `;
}

function renderSummary(summary, loading) {
  if (loading) return "";
  if (!summary) {
    return `
      <section class="storage-audit__summary">
        <p>${localize("KSA.Summary.NoAnalysis")}</p>
      </section>
    `;
  }

  const kindLines = Object.entries(summary.byKind)
    .sort((a, b) => b[1] - a[1])
    .map(([kind, count]) => `<li><span>${humanizeKind(kind)}</span><span>${count}</span></li>`)
    .join("");

  return `
    <section class="storage-audit__summary">
      <div class="storage-audit__stats">
        <article><span>${localize("KSA.Summary.Files")}</span><strong>${summary.files}</strong></article>
        <article><span>${localize("KSA.Summary.References")}</span><strong>${summary.references}</strong></article>
        <article><span>${localize("KSA.Summary.Findings")}</span><strong>${summary.findings}</strong></article>
        <article><span>${localize("KSA.Summary.High")}</span><strong>${summary.bySeverity.high}</strong></article>
        <article><span>${localize("KSA.Summary.Warning")}</span><strong>${summary.bySeverity.warning}</strong></article>
      </div>
      <div class="storage-audit__kinds">
        <h3>${localize("KSA.Summary.ByType")}</h3>
        <ul>${kindLines || `<li><span>${localize("KSA.Summary.NoFindings")}</span><span>0</span></li>`}</ul>
      </div>
      <div class="storage-audit__kinds">
        <h3>${localize("KSA.Summary.WorkBlocks")}</h3>
        <ul>
          <li><span>${localize("KSA.Summary.MissingTargets")}</span><span>${summary.grouped?.brokenReferences ?? 0}</span></li>
          <li><span>${localize("KSA.Summary.UnanchoredPackageTargets")}</span><span>${summary.grouped?.packageReferences ?? 0}</span></li>
          <li><span>${localize("KSA.Summary.OrphanCandidates")}</span><span>${summary.grouped?.orphans ?? 0}</span></li>
        </ul>
      </div>
    </section>
  `;
}

function renderGroupedFindingList(groupedFindings, hasAnalysis, loading, showAll) {
  if (loading || !hasAnalysis) return "";

  const sections = [];
  if (groupedFindings.nonPackageToPackage.length) {
    sections.push(renderGroupedSection(
      localize("KSA.Section.UnanchoredPackageTargets"),
      localize("KSA.Section.UnanchoredPackageTargetsDesc"),
      groupedFindings.nonPackageToPackage,
      group => `
        <article class="storage-audit__finding severity-${group.severity}">
          <header>
            <span class="storage-audit__severity">${severityLabel(group.severity)}</span>
            <strong>${formatCount(group.count, "KSA.Summary.References")}</strong>
          </header>
          <p><code>${escapeHtml(group.target)}</code></p>
          <p>${escapeHtml(group.shortReason)}</p>
          <dl>
            <div><dt>${localize("KSA.Field.OwnerPackage")}</dt><dd><code>${escapeHtml(group.ownerLabel)}</code></dd></div>
            <div><dt>${localize("KSA.Field.Assessment")}</dt><dd>${escapeHtml(group.explanation)}</dd></div>
          </dl>
          <p class="storage-audit__recommendation">${escapeHtml(group.recommendation)}</p>
          ${renderSampleSources(group.sources)}
        </article>
      `
    ));
  }

  if (groupedFindings.brokenReferences.length) {
    sections.push(renderGroupedSection(
      localize("KSA.Section.BrokenTargets"),
      localize("KSA.Section.BrokenTargetsDesc"),
      groupedFindings.brokenReferences,
      group => `
        <article class="storage-audit__finding severity-${group.severity}">
          <header>
            <span class="storage-audit__severity">${severityLabel(group.severity)}</span>
            <strong>${formatCount(group.count, "KSA.Summary.References")}</strong>
          </header>
          <p><code>${escapeHtml(group.target)}</code></p>
          <p>${escapeHtml(group.shortReason)}</p>
          ${group.targetKind === "wildcard" ? `<p>${localize("KSA.Finding.WildcardNoMatch")}</p>` : ""}
          <p class="storage-audit__recommendation">${escapeHtml(group.recommendation)}</p>
          ${renderSampleSources(group.sources)}
        </article>
      `
    ));
  }

  if (showAll && groupedFindings.orphans.length) {
    sections.push(renderGroupedSection(
      localize("KSA.Section.OrphanCandidates"),
      localize("KSA.Section.OrphanCandidatesDesc"),
      groupedFindings.orphans,
      group => `
        <article class="storage-audit__finding severity-${group.severity}">
          <header>
            <span class="storage-audit__severity">${severityLabel(group.severity)}</span>
            <code>${humanizeKind(group.kind)}</code>
          </header>
          <p><code>${escapeHtml(group.target)}</code></p>
          <p>${escapeHtml(group.reason)}</p>
          <p class="storage-audit__recommendation">${escapeHtml(group.recommendation)}</p>
        </article>
      `
    ));
  }

  if (!sections.length) {
    return `
      <section class="storage-audit__grouped">
        <div class="storage-audit__group-header">
          <h3>${localize("KSA.Section.WorkView")}</h3>
          <p>${format("KSA.Section.NoGrouped", { scope: localize(showAll ? "KSA.Scope.Empty" : "KSA.Scope.Warning") })}</p>
        </div>
      </section>
    `;
  }

  return `<section class="storage-audit__grouped">${sections.join("")}</section>`;
}

function renderGroupedSection(title, description, groups, renderGroup) {
  const items = groups.map(renderGroup).join("");
  return `
    <section class="storage-audit__group">
      <div class="storage-audit__group-header">
        <h3>${title}</h3>
        <p>${description}</p>
      </div>
      <div class="storage-audit__list">${items}</div>
    </section>
  `;
}

function renderFindingList(findings, hasAnalysis, loading, showAll, showRaw) {
  if (loading) {
    return `<section class="storage-audit__list"><p>${localize("KSA.Section.Running")}</p></section>`;
  }
  if (!hasAnalysis) {
    return `<section class="storage-audit__list"><p>${localize("KSA.Section.NoPrompt")}</p></section>`;
  }
  if (!showRaw) {
    return "";
  }
  if (!findings.length) {
    return `<section class="storage-audit__list"><p>${format("KSA.Section.NoRaw", { scope: localize(showAll ? "KSA.Scope.Empty" : "KSA.Scope.Warning") })}</p></section>`;
  }

  const items = findings.map(finding => `
    <article class="storage-audit__finding severity-${finding.severity}">
      <header>
        <span class="storage-audit__severity">${severityLabel(finding.severity)}</span>
        <span>${humanizeKind(finding.kind)}</span>
      </header>
      <p>${escapeHtml(finding.reason)}</p>
      <dl>
        <div><dt>${localize("KSA.Field.Target")}</dt><dd><code>${escapeHtml(finding.target.locator ?? `${finding.target.storage}:${finding.target.path}`)}</code></dd></div>
        ${finding.source ? `<div><dt>${localize("KSA.Field.Source")}</dt><dd>${renderSourceLink(finding.source)}</dd></div>` : ""}
      </dl>
      <p class="storage-audit__recommendation">${escapeHtml(finding.recommendation)}</p>
    </article>
  `).join("");

  return `
    <section class="storage-audit__list storage-audit__list--raw">
      <h3>${localize("KSA.Section.RawEntries")}</h3>
      ${items}
    </section>
  `;
}

function renderSampleSources(sources) {
  if (!sources.length) return "";
  const rows = sources.map(source => `<li>${renderSourceLink(source)}</li>`).join("");
  return `<div class="storage-audit__samples"><span>${localize("KSA.Section.Samples")}</span><ul>${rows}</ul></div>`;
}

function groupFindings(findings) {
  return {
    brokenReferences: groupByTarget(findings.filter(f => f.kind === "broken-reference")),
    nonPackageToPackage: groupByTarget(findings.filter(f => f.kind === "non-package-to-package-reference")),
    orphans: findings
      .filter(f => f.kind === "orphan-file")
      .sort(compareFindings)
      .map(finding => ({
        kind: finding.kind,
        severity: finding.severity,
        target: finding.target.locator ?? formatTarget(finding.target),
        reason: finding.reason,
        recommendation: finding.recommendation
      }))
  };
}

function groupByTarget(findings) {
  const grouped = new Map();
  for (const finding of findings) {
    const target = finding.target.locator ?? formatTarget(finding.target);
    const ownerLabel = deriveOwnerLabel(target);
    const current = grouped.get(target) ?? {
      kind: finding.kind,
      severity: finding.severity,
      target,
      count: 0,
      ownerLabel,
      explanation: localize("KSA.Finding.PackageExplanation"),
      shortReason: shortenReason(finding.reason),
      reason: finding.reason,
      recommendation: finding.recommendation,
      targetKind: finding.target.targetKind ?? "local-file",
      sources: new Map()
    };
    current.count += 1;
    if (finding.severity === "high") current.severity = "high";
    if (finding.source?.sourceLabel) {
      const key = finding.source.sourceUuid ?? finding.source.sourceLabel;
      current.sources.set(key, {
        sourceLabel: finding.source.sourceLabel,
        sourceName: finding.source.sourceName ?? null,
        sourceUuid: finding.source.sourceUuid ?? null,
        sourceTrail: finding.source.sourceTrail ?? null
      });
    }
    grouped.set(target, current);
  }
  return [...grouped.values()]
    .map(group => ({ ...group, sources: [...group.sources.values()] }))
    .sort((a, b) => compareSeverity(a.severity, b.severity) || (b.count - a.count) || a.target.localeCompare(b.target));
}

function shortenReason(reason) {
  return String(reason ?? "")
    .replace(/^world:[^ ]+ references /, "")
    .replace(/^Referenced file /, "")
    .replace(/^Wildcard reference /, "");
}

function deriveOwnerLabel(target) {
  const [, path] = String(target).split(":", 2);
  const parts = (path ?? "").split("/");
  if ((parts[0] === "modules") || (parts[0] === "systems")) {
    return `${parts[0]}:${parts[1] ?? "unknown"}`;
  }
  return localize("KSA.Owner.Unknown");
}

function compareFindings(a, b) {
  return compareSeverity(a.severity, b.severity)
    || formatTarget(a.target).localeCompare(formatTarget(b.target));
}

function compareSeverity(a, b) {
  const order = { high: 0, warning: 1, info: 2 };
  return (order[a] ?? 9) - (order[b] ?? 9);
}

function formatTarget(target) {
  return target.locator ?? `${target.storage}:${target.path}`;
}

function humanizeKind(kind) {
  const key = `KSA.FindingKind.${kind}`;
  const localized = localize(key);
  return localized === key ? kind : localized;
}

function serializeFinding(finding) {
  return {
    kind: finding.kind,
    severity: finding.severity,
    reason: finding.reason,
    recommendation: finding.recommendation,
    confidence: finding.confidence,
    target: finding.target,
    source: finding.source
      ? {
          sourceType: finding.source.sourceType,
          sourceLabel: finding.source.sourceLabel,
          sourceName: finding.source.sourceName,
          sourceUuid: finding.source.sourceUuid,
          sourceTrail: finding.source.sourceTrail,
          sourceScope: finding.source.sourceScope,
          rawValue: finding.source.rawValue,
          normalized: finding.source.normalized
        }
      : null
  };
}

function escapeHtml(value) {
  return String(value ?? "")
    .replace(/&/g, "&amp;")
    .replace(/</g, "&lt;")
    .replace(/>/g, "&gt;")
    .replace(/\"/g, "&quot;");
}

function localize(key) {
  return game.i18n?.localize(key) ?? key;
}

function format(key, data) {
  return game.i18n?.format(key, data) ?? key;
}

function severityLabel(severity) {
  const key = `KSA.Severity.${severity}`;
  const localized = localize(key);
  return localized === key ? severity : localized;
}

function formatCount(count, nounKey) {
  return `${count} ${localize(nounKey)}`;
}

function renderLocalizedCodeText(key, data, codeValues) {
  let text = format(key, data);
  for (const value of codeValues) {
    text = text.replaceAll(value, `@@CODE:${value}@@`);
  }
  return escapeHtml(text).replace(/@@CODE:([^@]+)@@/g, "<code>$1</code>");
}

function renderSourceLink(source) {
  const trail = Array.isArray(source.sourceTrail) && source.sourceTrail.length ? source.sourceTrail : null;
  if (trail) {
    return trail.map(renderTrailNode).join(' <span class="storage-audit__trail-separator">-&gt;</span> ');
  }

  const label = source.sourceName ? `${source.sourceLabel} (${source.sourceName})` : source.sourceLabel;
  if (!source.sourceUuid) return escapeHtml(label);
  return renderUuidLink(source.sourceUuid, label);
}

async function openSourceUuid(uuid) {
  if (!uuid) return;
  const document = await fromUuid(uuid);
  if (document?.sheet) {
    document.sheet.render(true, { focus: true });
    return;
  }
  if (document?.parent?.sheet) {
    document.parent.sheet.render(true, { focus: true });
    return;
  }
  ui.notifications.warn(format("KSA.Notify.OpenSourceFailed", { uuid }));
}

function renderTrailNode(node) {
  if (!node?.uuid) return escapeHtml(node?.label ?? "");
  return renderUuidLink(node.uuid, node.label ?? node.uuid);
}

function renderUuidLink(uuid, label) {
  return `<a class="content-link" draggable="true" data-link data-uuid="${escapeHtml(uuid)}" data-tooltip="${escapeHtml(label)}"><i class="fa-solid fa-file-lines"></i><span>${escapeHtml(label)}</span></a>`;
}