import { useEffect, useState } from "react";
import { Pressable, ScrollView, StyleSheet, Text, TextInput, View } from "react-native";
import { useLocalSearchParams, useRouter } from "expo-router";
import {
  importCanonScene,
  listCanonWorks,
  listCharacters,
  type CanonWork,
  type CharacterSummary,
  type ImportSceneLineInput,
  type ImportedSceneResult,
  type SceneLineType,
} from "../lib/api";

const LINE_TYPE_LABELS: Record<SceneLineType, string> = {
  DIALOGUE: "台詞",
  ACTION: "動作描寫",
  MONOLOGUE: "內心獨白",
  NARRATION: "敘述",
};
const LINE_TYPES = Object.keys(LINE_TYPE_LABELS) as SceneLineType[];

function emptyLine(): ImportSceneLineInput {
  return { lineType: "NARRATION", rawText: "" };
}

// T20-P4 匯入章節：與 apps/web 的 app/canon-import 對應同一份契約與流程，改用 RN 元件（chip 取代
// <select>）。多人在場且台詞沒有明示說話者時，既有的發言歸屬會把信心不足的句子隔離（QUARANTINED），
// 提交後直接依回應導向待裁決頁或顯示已投影。
export default function CanonImportScreen() {
  const router = useRouter();
  const { workId: presetWorkId } = useLocalSearchParams<{ workId?: string }>();
  const [works, setWorks] = useState<CanonWork[]>([]);
  const [workId, setWorkId] = useState("");
  const [characters, setCharacters] = useState<CharacterSummary[]>([]);
  const [chapterLabel, setChapterLabel] = useState("");
  const [volume, setVolume] = useState("1");
  const [storyOrder, setStoryOrder] = useState("1");
  const [summary, setSummary] = useState("");
  const [rawText, setRawText] = useState("");
  const [participantCharacterIds, setParticipantCharacterIds] = useState<string[]>([]);
  const [lines, setLines] = useState<ImportSceneLineInput[]>([emptyLine()]);
  const [pending, setPending] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [result, setResult] = useState<ImportedSceneResult | null>(null);

  useEffect(() => {
    void listCanonWorks().then((all) => {
      setWorks(all);
      if (presetWorkId && all.some((w) => w.id === presetWorkId)) {
        setWorkId(presetWorkId);
      }
    });
  }, [presetWorkId]);

  useEffect(() => {
    const selected = works.find((w) => w.id === workId);
    setStoryOrder(String((selected?.anchorStoryOrder ?? 0) + 1));
    setParticipantCharacterIds([]);
    setResult(null);
    setError(null);
    if (workId) {
      void listCharacters().then((all) => setCharacters(all.filter((c) => c.workId === workId)));
    } else {
      setCharacters([]);
    }
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [workId]);

  function toggleParticipant(characterId: string) {
    setParticipantCharacterIds((prev) =>
      prev.includes(characterId) ? prev.filter((id) => id !== characterId) : [...prev, characterId],
    );
  }

  function updateLine(index: number, patch: Partial<ImportSceneLineInput>) {
    setLines((prev) => prev.map((line, i) => (i === index ? { ...line, ...patch } : line)));
  }

  function removeLine(index: number) {
    setLines((prev) => prev.filter((_, i) => i !== index));
  }

  async function handleSubmit() {
    if (!workId || !chapterLabel.trim() || !summary.trim() || !rawText.trim() || pending) return;
    setPending(true);
    setError(null);
    setResult(null);
    try {
      const imported = await importCanonScene({
        workId,
        volume: Number(volume) || 1,
        chapterLabel: chapterLabel.trim(),
        storyOrder: Number(storyOrder) || 1,
        summary: summary.trim(),
        rawText: rawText.trim(),
        participantCharacterIds,
        lines: lines.filter((line) => line.rawText.trim().length > 0),
      });
      setResult(imported);
      setChapterLabel("");
      setSummary("");
      setRawText("");
      setLines([emptyLine()]);
    } catch (err) {
      setError(err instanceof Error ? err.message : "章節匯入失敗，請確認 api 服務是否已啟動");
    } finally {
      setPending(false);
    }
  }

  return (
    <ScrollView style={styles.flex} contentContainerStyle={styles.content}>
      <View style={styles.headerRow}>
        <Text style={styles.title}>匯入章節</Text>
        <Pressable onPress={() => router.back()}>
          <Text style={styles.backLink}>回到大廳</Text>
        </Pressable>
      </View>

      <View style={styles.chipRow}>
        {works.map((w) => (
          <Pressable key={w.id} onPress={() => setWorkId(w.id)} style={[styles.pickChip, workId === w.id ? styles.pickChipActive : null]}>
            <Text style={styles.pickChipText}>{w.title}</Text>
          </Pressable>
        ))}
      </View>

      {error && <Text style={styles.error}>{error}</Text>}

      {result && (
        <View style={styles.resultBox}>
          {result.pendingAdjudication ? (
            <>
              <Text style={styles.resultText}>匯入成功，但有台詞或矛盾待人工確認，暫不投影。</Text>
              <Pressable onPress={() => router.push("/canon-review")}>
                <Text style={styles.resultLink}>前往待裁決頁</Text>
              </Pressable>
            </>
          ) : (
            <Text style={styles.resultText}>
              匯入成功，已完成投影{result.projected ? "" : "（場景超前目前錨定點，先留存等待錨定點推進）"}。
            </Text>
          )}
        </View>
      )}

      {workId && (
        <>
          <TextInput value={chapterLabel} onChangeText={setChapterLabel} placeholder="章節標題（例如：第十章）" style={styles.input} />
          <View style={styles.row}>
            <TextInput value={volume} onChangeText={setVolume} placeholder="卷數" keyboardType="numeric" style={[styles.input, styles.rowInput]} />
            <TextInput
              value={storyOrder}
              onChangeText={setStoryOrder}
              placeholder="storyOrder"
              keyboardType="numeric"
              style={[styles.input, styles.rowInput]}
            />
          </View>
          <TextInput
            value={summary}
            onChangeText={setSummary}
            placeholder="場景摘要（客觀記錄，供角色記憶與情緒基線使用）"
            style={[styles.input, styles.textarea]}
            multiline
          />
          <TextInput value={rawText} onChangeText={setRawText} placeholder="原文（完整章節文本）" style={[styles.input, styles.textarea]} multiline />

          <Text style={styles.label}>在場角色</Text>
          <View style={styles.chipRow}>
            {characters.map((character) => (
              <Pressable
                key={character.id}
                onPress={() => toggleParticipant(character.id)}
                style={[styles.pickChip, participantCharacterIds.includes(character.id) ? styles.pickChipActive : null]}
              >
                <Text style={styles.pickChipText}>{character.aliases[0]?.formalName ?? character.id}</Text>
              </Pressable>
            ))}
          </View>

          <View style={styles.headerRow}>
            <Text style={styles.label}>逐句台詞／敘述</Text>
            <Pressable onPress={() => setLines((prev) => [...prev, emptyLine()])}>
              <Text style={styles.addLineLink}>新增一行</Text>
            </Pressable>
          </View>
          {lines.map((line, index) => (
            <View key={index} style={styles.lineRow}>
              <View style={styles.chipRow}>
                {LINE_TYPES.map((type) => (
                  <Pressable
                    key={type}
                    onPress={() => updateLine(index, { lineType: type })}
                    style={[styles.typeChip, line.lineType === type ? styles.pickChipActive : null]}
                  >
                    <Text style={styles.pickChipText}>{LINE_TYPE_LABELS[type]}</Text>
                  </Pressable>
                ))}
              </View>
              <TextInput
                value={line.rawText}
                onChangeText={(value) => updateLine(index, { rawText: value })}
                placeholder="這一句的內容"
                style={styles.input}
              />
              {line.lineType === "DIALOGUE" && (
                <View style={styles.chipRow}>
                  <Pressable
                    onPress={() => updateLine(index, { markerCharacterId: undefined, hasExplicitMarker: false })}
                    style={[styles.typeChip, !line.markerCharacterId ? styles.pickChipActive : null]}
                  >
                    <Text style={styles.pickChipText}>（無明示說話者）</Text>
                  </Pressable>
                  {characters.map((character) => (
                    <Pressable
                      key={character.id}
                      onPress={() => updateLine(index, { markerCharacterId: character.id, hasExplicitMarker: true })}
                      style={[styles.typeChip, line.markerCharacterId === character.id ? styles.pickChipActive : null]}
                    >
                      <Text style={styles.pickChipText}>{character.aliases[0]?.formalName ?? character.id}</Text>
                    </Pressable>
                  ))}
                </View>
              )}
              <Pressable onPress={() => removeLine(index)}>
                <Text style={styles.removeLineLink}>刪除這一行</Text>
              </Pressable>
            </View>
          ))}

          <Pressable
            onPress={() => void handleSubmit()}
            disabled={pending || !chapterLabel.trim() || !summary.trim() || !rawText.trim()}
            style={styles.submitButton}
          >
            <Text style={styles.submitButtonText}>匯入這一章</Text>
          </Pressable>
        </>
      )}
    </ScrollView>
  );
}

const styles = StyleSheet.create({
  flex: { flex: 1, backgroundColor: "#FFF5F7" },
  content: { padding: 16, gap: 10, paddingBottom: 40 },
  headerRow: { flexDirection: "row", alignItems: "center", justifyContent: "space-between" },
  title: { fontSize: 16, fontWeight: "bold", color: "#FF7E9D" },
  backLink: { fontSize: 12, color: "#8a6b6f" },
  chipRow: { flexDirection: "row", flexWrap: "wrap", gap: 6 },
  pickChip: { borderRadius: 999, borderWidth: 1, borderColor: "#E5D5D8", paddingHorizontal: 10, paddingVertical: 6 },
  pickChipActive: { backgroundColor: "#FFE1E9" },
  pickChipText: { fontSize: 12, color: "#222" },
  typeChip: { borderRadius: 999, borderWidth: 1, borderColor: "#E5D5D8", paddingHorizontal: 8, paddingVertical: 4 },
  error: { fontSize: 12, color: "#FF7E9D" },
  resultBox: { borderRadius: 12, borderWidth: 1, borderColor: "#E5D5D8", padding: 10, gap: 4 },
  resultText: { fontSize: 12, color: "#222" },
  resultLink: { fontSize: 12, fontWeight: "bold", color: "#FF7E9D" },
  input: {
    borderRadius: 12,
    borderWidth: 1,
    borderColor: "#E5D5D8",
    paddingHorizontal: 12,
    paddingVertical: 8,
    fontSize: 13,
    color: "#222",
  },
  row: { flexDirection: "row", gap: 8 },
  rowInput: { flex: 1 },
  textarea: { minHeight: 70, textAlignVertical: "top" },
  label: { fontSize: 12, fontWeight: "bold", color: "#8a6b6f" },
  addLineLink: { fontSize: 12, color: "#8a6b6f" },
  lineRow: { gap: 6, borderRadius: 12, borderWidth: 1, borderColor: "#E5D5D8", padding: 8 },
  removeLineLink: { fontSize: 11, color: "#8a6b6f", alignSelf: "flex-start" },
  submitButton: { borderRadius: 999, backgroundColor: "#FF7E9D", paddingVertical: 10, alignItems: "center" },
  submitButtonText: { fontSize: 14, fontWeight: "bold", color: "#fff" },
});