const AdmissionsPage = require("../models/admissionsPage");
const AUDIT_ACTIONS = require("../constants/auditAction");
const admissionsConfig = require("../utils/contentEditors/admissionsConfig");
const createPageContentController = require("./_createPageContentController");
const createRenderSingletonPageView = require("./_renderSingletonPageView");
const jsonHelper = require("../utils/jsonHelper");
const writeAuditLog = require("../audit/writeAuditLog");
const diffObject = require("../audit/diffObject");
const { ensureUniqueIds } = require("../utils/contentEditorIds");
const { ICON_OPTIONS } = require("../utils/contentEditors/sharedFields");

function getAdmissionsEditorUi() {
  return admissionsConfig.editorUi || {};
}

function getDefaultCalculatorOptionValues() {
  return getAdmissionsEditorUi().calculator?.defaultOption || {};
}

function getCalculatorOptionFieldConfig(fieldKey) {
  const calculatorTab = (admissionsConfig.tabs || []).find((tab) => tab.key === "calculator");
  const calculatorFields = calculatorTab?.schema?.fields || [];
  const optionsField = calculatorFields.find((field) => field.key === "options");
  const optionItemFields = optionsField?.itemSchema?.fields || [];

  return optionItemFields.find((field) => field.key === fieldKey) || {};
}

function hasDuplicateCalculatorOptionLabel(options, currentOptionId, nextLabel) {
  const normalizedLabel = String(nextLabel || "").trim().toLowerCase();
  if (!normalizedLabel) {
    return false;
  }

  return (options || []).some((option) => {
    if (String(option?.id || "") === String(currentOptionId || "")) {
      return false;
    }

    return String(option?.label || "").trim().toLowerCase() === normalizedLabel;
  });
}

function normalizePositiveAmount(value, fallback = "1") {
  const match = String(value || "").match(/\d[\d,]*/);
  const numericValue = Number((match ? match[0] : "").replace(/,/g, ""));
  return numericValue > 0 ? String(numericValue) : fallback;
}

function normalizeCalculatorOption(option, index, calculator) {
  const source = typeof option === "string" ? { label: option } : { ...(option || {}) };
  const defaultOption = getDefaultCalculatorOptionValues();
  const labelMaxLength = getCalculatorOptionFieldConfig("label").maxLength || 12;

  return {
    ...source,
    label: String(source.label || source.title || `Option ${index + 1}`).slice(0, labelMaxLength),
    paceLabel: String(source.paceLabel || calculator.paceLabel || defaultOption.paceLabel || "Target Pace"),
    minPaceLabel: String(source.minPaceLabel || calculator.minPaceLabel || defaultOption.minPaceLabel || "Relaxed"),
    maxPaceLabel: String(source.maxPaceLabel || calculator.maxPaceLabel || defaultOption.maxPaceLabel || "Accelerated"),
    resultLabel: String(
      source.resultLabel || calculator.resultLabel || defaultOption.resultLabel || "Estimated Monthly Payment",
    ),
    monthlyAmount: normalizePositiveAmount(
      source.monthlyAmount || calculator.monthlyAmount || defaultOption.monthlyAmount || "299",
      String(defaultOption.monthlyAmount || "299"),
    ),
    monthlySuffix: String(source.monthlySuffix || calculator.monthlySuffix || defaultOption.monthlySuffix || "/mo"),
    noteIcon: String(source.noteIcon || calculator.noteIcon || defaultOption.noteIcon || "fa-bolt"),
    note: String(source.note || calculator.note || defaultOption.note || ""),
  };
}

function normalizeCalculator(calculator) {
  const nextCalculator = { ...(calculator || {}) };
  const legacyOptions = Array.isArray(nextCalculator.modelOptions) ? nextCalculator.modelOptions : [];
  const rawOptions = Array.isArray(nextCalculator.options) && nextCalculator.options.length
    ? nextCalculator.options
    : legacyOptions;

  nextCalculator.title = String(nextCalculator.title || "");
  nextCalculator.description = String(nextCalculator.description || "");
  nextCalculator.cta = {
    label: String(nextCalculator?.cta?.label || "").slice(0, 15),
    href: String(nextCalculator?.cta?.href || ""),
  };

  nextCalculator.options = ensureUniqueIds(
    rawOptions.slice(0, 3).map((option, index) => normalizeCalculatorOption(option, index, nextCalculator)),
    (item) => item.id,
    (item) => item.label,
    "calculator-option",
  );

  delete nextCalculator.modelOptions;
  delete nextCalculator.paceLabel;
  delete nextCalculator.minPaceLabel;
  delete nextCalculator.maxPaceLabel;
  delete nextCalculator.resultLabel;
  delete nextCalculator.monthlyAmount;
  delete nextCalculator.monthlySuffix;
  delete nextCalculator.noteIcon;
  delete nextCalculator.note;

  return nextCalculator;
}

function normalizeTuitionPoint(point, index) {
  if (point && typeof point === "object" && !Array.isArray(point)) {
    const numericValue = Number(point.value);
    return {
      time: String(point.time || point.label || `Year ${index + 1}`),
      value: Number.isFinite(numericValue) && numericValue >= 0 ? numericValue : 0,
    };
  }

  const numericValue = Number(point);
  return {
    time: `Year ${index + 1}`,
    value: Number.isFinite(numericValue) && numericValue >= 0 ? numericValue : 0,
  };
}

function normalizeTuitionSeries(series, index) {
  const source = typeof series === "string" ? { label: series } : { ...(series || {}) };
  const rawPoints = Array.isArray(source.points) && source.points.length
    ? source.points
    : Array.isArray(source.values)
      ? source.values
      : [];

  return {
    label: String(source.label || `Series ${index + 1}`).slice(0, 40),
    color: String(source.color || "#0F172A"),
    points: rawPoints.map(normalizeTuitionPoint),
  };
}

function normalizeTuition(tuition) {
  const nextTuition = { ...(tuition || {}) };

  nextTuition.title = String(nextTuition.title || "");
  nextTuition.chartTitle = String(nextTuition.chartTitle || "");
  nextTuition.chartDescription = String(nextTuition.chartDescription || "");
  nextTuition.series = Array.isArray(nextTuition.series)
    ? nextTuition.series.map(normalizeTuitionSeries)
    : [];

  return nextTuition;
}

function normalizeAdmissionsPayload(rawPayload) {
  const payload = JSON.parse(JSON.stringify(rawPayload || {}));

  payload.process = {
    ...(payload.process || {}),
    id: "admissions-process",
  };
  payload.eligibility = {
    ...(payload.eligibility || {}),
    id: "eligibility",
  };
  payload.tuition = {
    ...normalizeTuition(payload.tuition),
    id: "tuition-breakdown",
  };
  payload.keyDates = {
    ...(payload.keyDates || {}),
    id: "key-dates",
  };
  payload.calculator = normalizeCalculator(payload.calculator);

  return payload;
}

const controller = createPageContentController({
  model: AdmissionsPage,
  modelName: "AdmissionsPage",
  auditAction: AUDIT_ACTIONS.UPDATE_ADMISSIONS,
  editorConfig: admissionsConfig,
  preparePayload: normalizeAdmissionsPayload,
  normalizeForEditor: normalizeAdmissionsPayload,
  normalizeForApi: normalizeAdmissionsPayload,
});

controller.index = async function index(req, res) {
  try {
    return await createRenderSingletonPageView({
      model: AdmissionsPage,
      editorConfig: admissionsConfig,
      view: "admin/admissions/index",
      normalizeForEditor: normalizeAdmissionsPayload,
    })(req, res);
  } catch (error) {
    console.error("admissions index error:", error);
    req.flash("error_msg", "Error loading Admissions Management");
    return req.session.save(() => res.redirect("/admin/dashboard"));
  }
};

controller.editCalculatorOption = async function editCalculatorOption(req, res) {
  try {
    const optionId = String(req.params.optionId || "");
    const doc = await AdmissionsPage.getSingle();
    const data = normalizeAdmissionsPayload(doc.toObject());
    const option = data.calculator.options.find((item) => item.id === optionId);

    if (!option) {
      req.flash("error_msg", "Calculator option not found");
      return req.session.save(() => res.redirect("/admin/admissions?tab=calculator"));
    }

    const frontendUrl = process.env.FRONTEND_URL || "http://localhost:3000";
    const backendUrl =
      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
    const fieldKeys = [
      "label",
      "paceLabel",
      "minPaceLabel",
      "maxPaceLabel",
      "resultLabel",
      "monthlyAmount",
      "monthlySuffix",
      "noteIcon",
      "note",
    ];
    const fieldConfig = fieldKeys.reduce((acc, key) => {
      acc[key] = getCalculatorOptionFieldConfig(key);
      return acc;
    }, {});

    return res.render("admin/admissions/calculator-option", {
      layout: "layouts/main",
      title: `Edit ${option.label}`,
      subtitle: "Update the calculator option details",
      option,
      existingOptionLabels: data.calculator.options
        .filter((item) => item.id !== optionId)
        .map((item) => item.label)
        .filter(Boolean),
      fieldLimits: {
        label: fieldConfig.label.maxLength || 12,
        paceLabel: fieldConfig.paceLabel.maxLength || 20,
        minPaceLabel: fieldConfig.minPaceLabel.maxLength || 7,
        maxPaceLabel: fieldConfig.maxPaceLabel.maxLength || 7,
        resultLabel: fieldConfig.resultLabel.maxLength || 40,
        monthlySuffix: fieldConfig.monthlySuffix.maxLength || 10,
        note: fieldConfig.note.maxLength || 60,
      },
      fieldConfig,
      iconOptions: ICON_OPTIONS,
      editorConfig: admissionsConfig,
      previewUrl: `${frontendUrl}${admissionsConfig.previewPath}`,
      currentPath: req.path,
      backendUrl,
      user: req.session.user,
    });
  } catch (error) {
    console.error("admissions calculator option index error:", error);
    req.flash("error_msg", "Error loading calculator option");
    return req.session.save(() => res.redirect("/admin/admissions?tab=calculator"));
  }
};

controller.updateCalculatorOption = async function updateCalculatorOption(req, res) {
  try {
    const optionId = String(req.params.optionId || "");
    const doc = await AdmissionsPage.getSingle();
    const beforeData = JSON.parse(JSON.stringify(doc.toObject()));
    const payload = normalizeAdmissionsPayload(beforeData);
    const optionIndex = payload.calculator.options.findIndex((item) => item.id === optionId);

    if (optionIndex === -1) {
      req.flash("error_msg", "Calculator option not found");
      return req.session.save(() => res.redirect("/admin/admissions?tab=calculator"));
    }

    const nextLabel = String(req.body.label || "").trim().slice(0, getCalculatorOptionFieldConfig("label").maxLength || 12);
    if (hasDuplicateCalculatorOptionLabel(payload.calculator.options, optionId, nextLabel)) {
      req.flash("error_msg", `Option label "${nextLabel}" already exists. Please use a unique label.`);
      return req.session.save(() => res.redirect(`/admin/admissions/calculator/${optionId}`));
    }

    payload.calculator.options[optionIndex] = {
      ...payload.calculator.options[optionIndex],
      label: nextLabel,
      paceLabel: String(req.body.paceLabel || "").trim(),
      minPaceLabel: String(req.body.minPaceLabel || "").trim(),
      maxPaceLabel: String(req.body.maxPaceLabel || "").trim(),
      resultLabel: String(req.body.resultLabel || "").trim(),
      monthlyAmount: normalizePositiveAmount(req.body.monthlyAmount, payload.calculator.options[optionIndex].monthlyAmount || "1"),
      monthlySuffix: String(req.body.monthlySuffix || "").trim(),
      noteIcon: String(req.body.noteIcon || "").trim(),
      note: String(req.body.note || "").trim(),
    };

    const normalizedPayload = normalizeAdmissionsPayload(payload);
    doc.set(normalizedPayload);
    Object.keys(normalizedPayload).forEach((key) => doc.markModified(key));
    await doc.save();

    const afterData = JSON.parse(JSON.stringify(doc.toObject()));
    const changes = diffObject(beforeData, afterData);

    if (changes.length > 0) {
      await writeAuditLog({
        model: "AdmissionsPage",
        documentId: doc._id,
        action: AUDIT_ACTIONS.UPDATE_ADMISSIONS,
        before: beforeData,
        after: afterData,
        changes,
        req,
      });
    }

    const finalData = await AdmissionsPage
      .findOne()
      .select("-_id -__v -createdAt -updatedAt")
      .lean();
    jsonHelper.writeJsonFile(admissionsConfig.dataFile, normalizeAdmissionsPayload(finalData));

    req.flash("success_msg", "Calculator option updated successfully");
    return req.session.save(() => res.redirect(`/admin/admissions/calculator/${optionId}`));
  } catch (error) {
    console.error("admissions calculator option update error:", error);
    req.flash("error_msg", `Error updating calculator option: ${error.message}`);
    return req.session.save(() => res.redirect(`/admin/admissions/calculator/${req.params.optionId}`));
  }
};

module.exports = controller;