import type {
  ComplianceScore,
  ConsentModal,
  DarkPatternIssue,
  ScannedCookie,
  NetworkRequest,
} from "../types.js";
import { analyzeButtonWording, analyzeModalText } from "./wording.js";
import { detectColourNudging } from "./colour.js";

interface ComplianceInput {
  modal: ConsentModal;
  privacyPolicyUrl: string | null;
  cookiesBeforeInteraction: ScannedCookie[];
  cookiesAfterAccept: ScannedCookie[];
  cookiesAfterReject: ScannedCookie[];
  networkBeforeInteraction: NetworkRequest[];
  networkAfterAccept: NetworkRequest[];
  networkAfterReject: NetworkRequest[];
}

export function analyzeCompliance(input: ComplianceInput): ComplianceScore {
  const issues: DarkPatternIssue[] = [];

  // Determine whether a consent mechanism is actually required
  const hasNonEssentialCookies = [
    ...input.cookiesBeforeInteraction,
    ...input.cookiesAfterAccept,
  ].some((c) => c.requiresConsent);
  const hasNonEssentialTrackers = [
    ...input.networkBeforeInteraction,
    ...input.networkAfterAccept,
  ].some((r) => r.requiresConsent);
  const consentRequired = hasNonEssentialCookies || hasNonEssentialTrackers;

  // Run wording analysis once — modal may not be detected, so these can be null
  const wordingResult = input.modal.detected ? analyzeButtonWording(input.modal.buttons) : null;
  const textResult = input.modal.detected ? analyzeModalText(input.modal.text) : null;

  // ── A. Consent validity (0-25) ────────────────────────────────
  let consentValidity = 25;

  if (!input.modal.detected && consentRequired) {
    issues.push({
      type: "no-reject-button",
      severity: "critical",
      description: "No cookie consent modal detected",
      evidence: "A consent mechanism is required before depositing non-essential cookies",
    });
    consentValidity = 0;
  } else if (input.modal.detected) {
    // Wording analysis (wordingResult / textResult hoisted above)
    issues.push(...wordingResult!.issues, ...textResult!.issues);

    // Pre-ticked checkboxes
    const preTicked = input.modal.checkboxes.filter((c) => c.isCheckedByDefault);
    if (preTicked.length > 0) {
      issues.push({
        type: "pre-ticked",
        severity: "critical",
        description: `${preTicked.length} checkbox(es) pre-ticked by default`,
        evidence: `Pre-ticked boxes are invalid consent under RGPD Recital 32. Affected: ${preTicked.map((c) => c.label || c.name).join(", ")}`,
      });
      consentValidity -= 10;
    }

    // Missing info deductions
    if (textResult!.missingInfo.includes("purposes")) consentValidity -= 5;
    if (textResult!.missingInfo.includes("third-parties")) consentValidity -= 5;
    if (textResult!.missingInfo.length >= 3) consentValidity -= 5;
  }

  // ── B. Easy refusal (0-25) ────────────────────────────────────
  let easyRefusal = 25;

  if (!input.modal.detected && consentRequired) {
    easyRefusal = 0;
  } else if (input.modal.detected) {
    const acceptButton = input.modal.buttons.find((b) => b.type === "accept");
    const rejectButton = input.modal.buttons.find((b) => b.type === "reject");

    if (!rejectButton) {
      issues.push({
        type: "buried-reject",
        severity: "critical",
        description: "No reject button on first layer",
        evidence: "CNIL (2022) requires reject to require no more clicks than accept",
      });
      easyRefusal -= 15;
    } else if (rejectButton.clickDepth > (acceptButton?.clickDepth ?? 1)) {
      issues.push({
        type: "click-asymmetry",
        severity: "critical",
        description: "Reject requires more clicks than accept",
        evidence: `Accept: ${acceptButton?.clickDepth ?? 1} click(s), Reject: ${rejectButton.clickDepth} click(s)`,
      });
      easyRefusal -= 15;
    }

    // Visual asymmetry: if accept button is significantly larger/more prominent
    if (acceptButton && rejectButton && acceptButton.boundingBox && rejectButton.boundingBox) {
      const acceptArea = acceptButton.boundingBox.width * acceptButton.boundingBox.height;
      const rejectArea = rejectButton.boundingBox.width * rejectButton.boundingBox.height;
      if (acceptArea > rejectArea * 3) {
        issues.push({
          type: "asymmetric-prominence",
          severity: "warning",
          description: "Accept button is significantly larger than reject button",
          evidence: `Accept area: ${Math.round(acceptArea)}px², Reject area: ${Math.round(rejectArea)}px²`,
        });
        easyRefusal -= 5;
      }
    }

    // Indirect reject label ("continuer sans accepter", "continue without accepting"…)
    if (wordingResult?.hasIndirectRejectLabel) {
      easyRefusal -= 5;
    }

    // Colour nudging: green accept + grey/red reject
    if (acceptButton && rejectButton) {
      const { isNudging, acceptHue, rejectHue } = detectColourNudging(
        acceptButton.backgroundColor,
        rejectButton.backgroundColor,
      );
      if (isNudging) {
        issues.push({
          type: "nudging",
          severity: "warning",
          description:
            'Accept button uses a "positive" colour (green) while reject is visually de-emphasised',
          evidence: `Accept: ${acceptButton.backgroundColor} (${acceptHue}), Reject: ${rejectButton.backgroundColor} (${rejectHue}) — EDPB Guidelines 03/2022 § 3.3.3`,
        });
        easyRefusal -= 5;
      }
    }

    // Font size asymmetry
    if (acceptButton?.fontSize && rejectButton?.fontSize) {
      if (acceptButton.fontSize > rejectButton.fontSize * 1.3) {
        issues.push({
          type: "nudging",
          severity: "warning",
          description: "Accept button font is significantly larger than reject button",
          evidence: `Accept: ${acceptButton.fontSize}px, Reject: ${rejectButton.fontSize}px`,
        });
        easyRefusal -= 5;
      }
    }

    // Contrast ratio: reject button must meet minimum legibility
    if (rejectButton && rejectButton.contrastRatio !== null) {
      const ratio = rejectButton.contrastRatio;
      if (ratio < 3.0) {
        issues.push({
          type: "asymmetric-prominence",
          severity: "critical",
          description: "Reject button has critically low contrast ratio",
          evidence: `Contrast ratio ${ratio}:1 — WCAG AA requires 4.5:1 for normal text (${rejectButton.backgroundColor ?? "?"} / ${rejectButton.textColor ?? "?"})`,
        });
        easyRefusal -= 10;
      } else if (ratio < 4.5) {
        issues.push({
          type: "asymmetric-prominence",
          severity: "warning",
          description: "Reject button contrast ratio is below WCAG AA threshold",
          evidence: `Contrast ratio ${ratio}:1 — WCAG AA requires 4.5:1 for normal text (${rejectButton.backgroundColor ?? "?"} / ${rejectButton.textColor ?? "?"})`,
        });
        easyRefusal -= 5;
      }

      // Relative contrast asymmetry: accept visually pops, reject is muted
      const acceptContrast = acceptButton?.contrastRatio ?? null;
      if (acceptContrast !== null && acceptContrast >= rejectButton.contrastRatio * 1.5) {
        issues.push({
          type: "asymmetric-prominence",
          severity: "warning",
          description: "Accept button has significantly higher contrast than reject button",
          evidence: `Accept: ${acceptContrast}:1, Reject: ${rejectButton.contrastRatio}:1`,
        });
        easyRefusal -= 3;
      }
    }
  }

  // ── C. Transparency (0-25) ────────────────────────────────────
  let transparency = 25;

  if (!input.modal.detected && consentRequired) {
    transparency = 0;
  } else if (input.modal.detected) {
    if (!input.modal.hasGranularControls) {
      transparency -= 10;
    }
    // Already deducted in consentValidity for missing info
    if (textResult!.missingInfo.length > 0) {
      transparency -= textResult!.missingInfo.length * 3;
    }
    // No privacy policy link in the modal
    if (!input.modal.privacyPolicyUrl) {
      issues.push({
        type: "missing-info",
        severity: "warning",
        description: "No privacy policy link found in the consent modal",
        evidence:
          "GDPR Art. 13 requires the privacy policy to be accessible from the consent interface",
      });
      transparency -= 5;
    }
  }

  // No privacy policy link anywhere on the page (only relevant when consent is required)
  if (!input.privacyPolicyUrl && consentRequired) {
    issues.push({
      type: "missing-info",
      severity: "warning",
      description: "No privacy policy link found on the page",
      evidence: "A privacy policy must be accessible from every page (GDPR Art. 13)",
    });
    transparency -= 3;
  }

  // ── D. Cookie behavior (0-25) ─────────────────────────────────
  let cookieBehavior = 25;

  // Cookies deposited before any interaction that require consent
  const illegalPreConsentCookies = input.cookiesBeforeInteraction.filter((c) => c.requiresConsent);

  if (illegalPreConsentCookies.length > 0) {
    issues.push({
      type: "auto-consent",
      severity: "critical",
      description: `${illegalPreConsentCookies.length} non-essential cookie(s) deposited before any interaction`,
      evidence: illegalPreConsentCookies.map((c) => `${c.name} (${c.category})`).join(", "),
    });
    cookieBehavior -= Math.min(20, illegalPreConsentCookies.length * 4);
  }

  // Non-essential cookies persisting after reject
  const consentCookiesAfterReject = input.cookiesAfterReject.filter(
    (c) => c.requiresConsent && c.capturedAt === "after-reject",
  );

  if (consentCookiesAfterReject.length > 0) {
    issues.push({
      type: "auto-consent",
      severity: "critical",
      description: `${consentCookiesAfterReject.length} non-essential cookie(s) persist after rejection`,
      evidence: consentCookiesAfterReject.map((c) => `${c.name} (${c.category})`).join(", "),
    });
    cookieBehavior -= Math.min(15, consentCookiesAfterReject.length * 3);
  }

  // Network trackers firing before interaction
  const preInteractionTrackers = input.networkBeforeInteraction.filter((r) => r.requiresConsent);

  if (preInteractionTrackers.length > 0) {
    issues.push({
      type: "auto-consent",
      severity: "critical",
      description: `${preInteractionTrackers.length} tracker request(s) fired before any consent`,
      evidence: [...new Set(preInteractionTrackers.map((r) => r.trackerName ?? r.url))]
        .slice(0, 5)
        .join(", "),
    });
    cookieBehavior -= Math.min(10, preInteractionTrackers.length * 2);
  }

  // Clamp all scores
  const clamp = (v: number) => Math.max(0, Math.min(25, v));
  const breakdown = {
    consentValidity: clamp(consentValidity),
    easyRefusal: clamp(easyRefusal),
    transparency: clamp(transparency),
    cookieBehavior: clamp(cookieBehavior),
  };

  const total = Object.values(breakdown).reduce((a, b) => a + b, 0);

  return {
    total,
    breakdown,
    issues,
    grade: scoreToGrade(total),
  };
}

function scoreToGrade(score: number): "A" | "B" | "C" | "D" | "F" {
  if (score >= 90) return "A";
  if (score >= 75) return "B";
  if (score >= 55) return "C";
  if (score >= 35) return "D";
  return "F";
}