import { BlurView } from "expo-blur";
import React, { useEffect, useRef, useState } from "react";
import { Platform, Text, View } from "react-native";
import useMinuit from "react-native-minuit/src/hooks/useMinuit.js";
import alert from "../../components/Alert";
import GradientButton from "../../components/GradientButton";
import ProgressBar from "../../components/ProgressBar";
import firebase from "../../config/firebase";
import { Routes } from "../../navigation";
import { navigate } from "../../navigation/NavigationService";
import { useUser } from "../../providers/UserDataProvider";
import { Palette, Style } from "../../styles";
import { FONT_FAMILY } from "../../styles/Fonts";
import {
  normalizeStructureType,
  sanitizeStructureList,
  segmentRequiresLyrics,
} from "../../utils/songStructure";

const FAKE_PROGRESS_MAX = 96;
const PROGRESS_INTERVAL_MS = 250;
const CUSTOM_SANITIZE_OPTIONS = { autoInjectPreChorus: false };

const CreatingLyrics = ({ active, config, selections }) => {
  const [progress, setProgress] = useState(0);
  const [called, setCalled] = useState(false);
  const [result, setResult] = useState(null);
  const [saved, setSaved] = useState(false);
  const [error, setError] = useState(null);
  const hasShownErrorAlert = useRef(false);
  const { setIsLoading } = useMinuit();
  const { updateProjectData } = useUser();
  const progressValue = Math.max(0, Math.min(100, Math.round(progress)));

  // Reset when becomes active
  useEffect(() => {
    if (active) {
      setCalled(false);
      setResult(null);
      setProgress(0);
      setSaved(false);
      setError(null);
      hasShownErrorAlert.current = false;
    }
  }, [active]);

  useEffect(() => {
    if (!active) return undefined;

    const interval = setInterval(() => {
      setProgress((prevProgress) => {
        if (result || error) return prevProgress;
        if (prevProgress >= FAKE_PROGRESS_MAX) {
          return FAKE_PROGRESS_MAX;
        }

        const increment = prevProgress < 60 ? 1 : prevProgress < 80 ? 0.6 : 0.3;

        const next = prevProgress + increment;
        return next >= FAKE_PROGRESS_MAX ? FAKE_PROGRESS_MAX : next;
      });
    }, PROGRESS_INTERVAL_MS);

    return () => clearInterval(interval);
  }, [active, result, error]);

  useEffect(() => {
    const run = async () => {
      try {
        setCalled(true);
        console.log("🚀 [CreatingLyrics] Lancement de la génération", {
          platform: Platform.OS,
        });
        const sanitizedStructure = sanitizeStructureList(
          config?.structure,
          CUSTOM_SANITIZE_OPTIONS,
        );
        const callable = firebase
          .functions()
          .httpsCallable("lyrics-generateLyrics");
        const { data } = await callable({
          objective: config?.objective,
          context: config?.context,
          emotion: config?.emotion,
          style: config?.style,
          audience: config?.audience,
          structure: sanitizedStructure,
          rhymes: config?.rhymes,
        });
        const rawLyrics = Array.isArray(data?.lyrics) ? data.lyrics : [];
        const normalizedLyrics = rawLyrics.map((section) => {
          const sanitizedType = normalizeStructureType(section?.type);
          return {
            ...section,
            type: sanitizedType,
            lyrics: section?.lyrics || "",
          };
        });

        const remaining = [...normalizedLyrics];
        const takeForType = (type, { fallback = true } = {}) => {
          const index = remaining.findIndex((item) => item.type === type);
          if (index !== -1) {
            return remaining.splice(index, 1)[0];
          }
          if (!fallback) return null;
          return remaining.shift() || null;
        };

        const structuredLyrics = sanitizedStructure.length
          ? sanitizedStructure.map((rawType) => {
              const type = normalizeStructureType(rawType);
              if (!segmentRequiresLyrics(type)) {
                const match = takeForType(type, { fallback: false });
                return { type, lyrics: match?.lyrics || "" };
              }
              const match = takeForType(type, { fallback: true });
              return {
                type,
                lyrics: match?.lyrics || "",
              };
            })
          : normalizedLyrics;

        const alignedLyrics = structuredLyrics.concat(remaining);
        const processedResult = {
          ...data,
          lyrics: alignedLyrics,
          structure: sanitizedStructure,
        };
        setResult(processedResult);
        setProgress(100);
        console.log("✨ [CreatingLyrics] Génération réussie");
      } catch (e) {
        console.error("🔥 [CreatingLyrics] Erreur de génération", e);
        const rawMessage = typeof e?.message === "string" ? e.message : "";
        const cleanedMessage = rawMessage.replace(
          /^functions error: \w+-\w+:\s*/i,
          "",
        );
        setError({
          message:
            cleanedMessage?.length > 0
              ? cleanedMessage
              : "Une erreur est survenue lors de la génération des paroles.",
          code: e?.code,
          details: e?.details,
        });
      } finally {
        await setIsLoading(false);
      }
    };

    if (active && !called) {
      run();
    }
  }, [active, called, config, setIsLoading]);

  // Lorsque la génération est terminée, enregistrer et naviguer automatiquement vers Lyrics
  useEffect(() => {
    const autoSaveAndGo = async () => {
      try {
        if (saved) return;
        setSaved(true);
        await setIsLoading(true);
        console.log("💾 [CreatingLyrics] Sauvegarde automatique des paroles");
        const sanitizedStructure = sanitizeStructureList(
          result?.structure || config?.structure,
          CUSTOM_SANITIZE_OPTIONS,
        );
        const baseConfig =
          config && typeof config === "object" && !Array.isArray(config)
            ? { ...config }
            : {};
        if (sanitizedStructure.length > 0) {
          baseConfig.structure = sanitizedStructure;
        } else if (
          Object.prototype.hasOwnProperty.call(baseConfig, "structure")
        ) {
          delete baseConfig.structure;
        }
        const persistedConfig =
          Object.keys(baseConfig).length > 0 ? baseConfig : null;

        let persistedSelections =
          selections &&
          typeof selections === "object" &&
          !Array.isArray(selections)
            ? { ...selections }
            : null;
        if (persistedSelections) {
          if ("customStructure" in persistedSelections) {
            persistedSelections.customStructure = sanitizeStructureList(
              persistedSelections.customStructure,
              CUSTOM_SANITIZE_OPTIONS,
            );
          }
          if ("parsedStructure" in persistedSelections) {
            persistedSelections.parsedStructure = sanitizeStructureList(
              persistedSelections.parsedStructure,
            );
          }
        }

        await updateProjectData({
          title: result?.title || "",
          lyrics: Array.isArray(result?.lyrics) ? result.lyrics : [],
          description: result?.lyricsDescription,
          config: persistedConfig,
          selections: persistedSelections,
          hasLyrics: false,
        });
        navigate(Routes.Lyrics);
      } catch (e) {
        console.error("⚠️ [CreatingLyrics] Erreur lors de la sauvegarde", e);
      } finally {
        await setIsLoading(false);
      }
    };

    if (active && result && progress >= 100 && !saved && !error) {
      autoSaveAndGo();
    }
  }, [
    active,
    result,
    progress,
    saved,
    error,
    setIsLoading,
    updateProjectData,
    config,
    selections,
  ]);

  useEffect(() => {
    if (error && !hasShownErrorAlert.current) {
      hasShownErrorAlert.current = true;
      const redirect = () => {
        console.log("↩️ [CreatingLyrics] Retour à WritingLyrics après erreur");
        navigate(Routes.WritingLyrics);
      };

      alert(
        "Brief à reformuler",
        __DEV__ ? error.message : "Une erreur s'est produite",
        [
          {
            text: "OK",
            onPress: redirect,
          },
        ],
        { cancelable: false },
      );

      if (Platform.OS === "web") {
        redirect();
      }
    }
  }, [error]);

  return (
    <View
      style={{
        flex: 1,
        ...Style.containerCenter,
      }}
    >
      <View
        style={{
          width: "100%",
          height: "50%",
        }}
      >
        <View
          style={{
            borderRadius: 20,
            overflow: "hidden",
            backgroundColor: "#0F0C1933",
          }}
        >
          <BlurView
            intensity={Platform.OS !== "ios" ? 10 : 40}
            tint="dark"
            style={{ padding: 10, paddingBottom: 20 }}
          >
            <View style={{ justifyContent: "flex-end", gap: 20 }}>
              <Text
                style={{
                  fontSize: 22,
                  color: Palette.white,
                  fontFamily: FONT_FAMILY.InterSemiBold,
                  textAlign: "center",
                }}
              >
                {error
                  ? "Impossible de générer les paroles"
                  : "Ton texte est\nen cours de création"}
              </Text>
              <View style={{ alignItems: "center", gap: 16 }}>
                <ProgressBar gradient progress={progressValue} />
                <Text
                  style={{
                    fontSize: 14,
                    color: Palette.white,
                    fontFamily: FONT_FAMILY.InterRegular,
                  }}
                >
                  {progressValue}%
                </Text>
              </View>
              {!saved && result && !error && (
                <GradientButton
                  title="Découvrir mon texte"
                  containerStyle={{
                    width: "80%",
                    alignSelf: "center",
                  }}
                  onPress={async () => {
                    try {
                      if (saved) return;
                      setSaved(true);
                      await setIsLoading(true);
                      console.log(
                        "📄 [CreatingLyrics] Consultation manuelle du texte",
                      );
                      await updateProjectData({
                        title: result?.title || "",
                        lyrics: Array.isArray(result?.lyrics)
                          ? result.lyrics
                          : [],
                        config: config || null,
                        selections: selections || null,
                        hasLyrics: false,
                      });
                      navigate(Routes.Lyrics);
                    } catch (e) {
                      console.error(
                        "⚠️ [CreatingLyrics] Erreur lors de l'ouverture manuelle",
                        e,
                      );
                    } finally {
                      await setIsLoading(false);
                    }
                  }}
                />
              )}
            </View>
          </BlurView>
        </View>
      </View>
    </View>
  );
};

export default CreatingLyrics;