import { useState, useEffect } from "react";
import {
  View,
  Text,
  TextInput,
  ScrollView,
  Switch,
  Pressable,
  Alert,
} from "react-native";
import * as SecureStore from "expo-secure-store";
import { Colors } from "@/constants/theme";
import { DEFAULT_TEMPLATE } from "@/lib/markdown";

const KEYS = {
  INPUT_MODE: "pref_input_mode",
  HOME_VIEW: "pref_home_view",
  AI_ENABLED: "pref_ai_enabled",
  AI_KEY: "pref_ai_key",
  GITEA_URL: "gitea_url",
  GITEA_TOKEN: "gitea_token",
  GITEA_OWNER: "gitea_owner",
  GITEA_REPO: "gitea_repo",
  MD_TEMPLATE: "md_template",
} as const;

const LABEL = {
  color: Colors.text2,
  fontSize: 11,
  fontWeight: "700" as const,
  textTransform: "uppercase" as const,
  letterSpacing: 0.6,
  marginBottom: 6,
} as const;

const SECTION_TITLE = {
  color: Colors.text1,
  fontSize: 16,
  fontWeight: "700" as const,
  marginTop: 28,
  marginBottom: 12,
} as const;

const INPUT = {
  backgroundColor: Colors.surface,
  borderColor: Colors.border,
  borderWidth: 1,
  borderRadius: 8,
  color: Colors.text1,
  padding: 12,
  fontSize: 14,
  marginBottom: 14,
  fontFamily: "monospace",
} as const;

export default function SettingsScreen() {
  const [inputMode, setInputMode] = useState<"voice" | "form">("form");
  const [homeView, setHomeView] = useState<"dashboard" | "capture">("dashboard");
  const [aiEnabled, setAiEnabled] = useState(false);
  const [aiKey, setAiKey] = useState("");
  const [giteaUrl, setGiteaUrl] = useState("");
  const [giteaToken, setGiteaToken] = useState("");
  const [giteaOwner, setGiteaOwner] = useState("");
  const [giteaRepo, setGiteaRepo] = useState("");
  const [mdTemplate, setMdTemplate] = useState(DEFAULT_TEMPLATE);
  const [saved, setSaved] = useState(false);

  useEffect(() => {
    (async () => {
      const [im, hv, ai, key, gu, gt, go, gr, tpl] = await Promise.all([
        SecureStore.getItemAsync(KEYS.INPUT_MODE),
        SecureStore.getItemAsync(KEYS.HOME_VIEW),
        SecureStore.getItemAsync(KEYS.AI_ENABLED),
        SecureStore.getItemAsync(KEYS.AI_KEY),
        SecureStore.getItemAsync(KEYS.GITEA_URL),
        SecureStore.getItemAsync(KEYS.GITEA_TOKEN),
        SecureStore.getItemAsync(KEYS.GITEA_OWNER),
        SecureStore.getItemAsync(KEYS.GITEA_REPO),
        SecureStore.getItemAsync(KEYS.MD_TEMPLATE),
      ]);
      if (im) setInputMode(im as "voice" | "form");
      if (hv) setHomeView(hv as "dashboard" | "capture");
      if (ai) setAiEnabled(ai === "true");
      if (key) setAiKey(key);
      if (gu) setGiteaUrl(gu);
      if (gt) setGiteaToken(gt);
      if (go) setGiteaOwner(go);
      if (gr) setGiteaRepo(gr);
      if (tpl) setMdTemplate(tpl);
    })();
  }, []);

  async function handleSave() {
    await Promise.all([
      SecureStore.setItemAsync(KEYS.INPUT_MODE, inputMode),
      SecureStore.setItemAsync(KEYS.HOME_VIEW, homeView),
      SecureStore.setItemAsync(KEYS.AI_ENABLED, String(aiEnabled)),
      SecureStore.setItemAsync(KEYS.AI_KEY, aiKey),
      SecureStore.setItemAsync(KEYS.GITEA_URL, giteaUrl),
      SecureStore.setItemAsync(KEYS.GITEA_TOKEN, giteaToken),
      SecureStore.setItemAsync(KEYS.GITEA_OWNER, giteaOwner),
      SecureStore.setItemAsync(KEYS.GITEA_REPO, giteaRepo),
      SecureStore.setItemAsync(KEYS.MD_TEMPLATE, mdTemplate),
    ]);
    setSaved(true);
    setTimeout(() => setSaved(false), 2000);
  }

  function ToggleRow({
    label,
    value,
    onValueChange,
  }: {
    label: string;
    value: boolean;
    onValueChange: (v: boolean) => void;
  }) {
    return (
      <View
        style={{
          flexDirection: "row",
          justifyContent: "space-between",
          alignItems: "center",
          backgroundColor: Colors.surface,
          borderRadius: 8,
          padding: 14,
          marginBottom: 10,
        }}
      >
        <Text style={{ color: Colors.text1, fontSize: 15 }}>{label}</Text>
        <Switch
          value={value}
          onValueChange={onValueChange}
          trackColor={{ true: Colors.primary, false: Colors.border }}
          thumbColor="#fff"
        />
      </View>
    );
  }

  function SegmentRow({
    label,
    options,
    value,
    onChange,
  }: {
    label: string;
    options: { key: string; label: string }[];
    value: string;
    onChange: (v: string) => void;
  }) {
    return (
      <View style={{ marginBottom: 16 }}>
        <Text style={LABEL}>{label}</Text>
        <View style={{ flexDirection: "row", gap: 8 }}>
          {options.map((opt) => (
            <Pressable
              key={opt.key}
              onPress={() => onChange(opt.key)}
              style={{
                flex: 1,
                backgroundColor:
                  value === opt.key ? Colors.primary : Colors.surface,
                borderRadius: 8,
                padding: 12,
                alignItems: "center",
                borderWidth: 1,
                borderColor:
                  value === opt.key ? Colors.primary : Colors.border,
              }}
            >
              <Text
                style={{
                  color: value === opt.key ? "#fff" : Colors.text2,
                  fontWeight: "600",
                  fontSize: 13,
                }}
              >
                {opt.label}
              </Text>
            </Pressable>
          ))}
        </View>
      </View>
    );
  }

  return (
    <ScrollView
      style={{ flex: 1, backgroundColor: Colors.bg }}
      contentContainerStyle={{ padding: 16, paddingBottom: 48 }}
      keyboardShouldPersistTaps="handled"
    >
      <Text style={SECTION_TITLE}>Preferences</Text>

      <SegmentRow
        label="Default Input"
        value={inputMode}
        onChange={(v) => setInputMode(v as "voice" | "form")}
        options={[
          { key: "form", label: "Form" },
          { key: "voice", label: "Voice" },
        ]}
      />

      <SegmentRow
        label="Home View"
        value={homeView}
        onChange={(v) => setHomeView(v as "dashboard" | "capture")}
        options={[
          { key: "dashboard", label: "Dashboard" },
          { key: "capture", label: "Quick Capture" },
        ]}
      />

      <Text style={SECTION_TITLE}>AI (optional)</Text>
      <ToggleRow
        label="Enable AI assistance"
        value={aiEnabled}
        onValueChange={setAiEnabled}
      />
      {aiEnabled && (
        <>
          <Text style={LABEL}>API Key</Text>
          <TextInput
            style={INPUT}
            value={aiKey}
            onChangeText={setAiKey}
            placeholder="sk-..."
            placeholderTextColor={Colors.textDim}
            secureTextEntry
            autoCapitalize="none"
          />
        </>
      )}

      <Text style={SECTION_TITLE}>Gitea</Text>
      <Text style={LABEL}>Instance URL</Text>
      <TextInput
        style={INPUT}
        value={giteaUrl}
        onChangeText={setGiteaUrl}
        placeholder="https://homegit.gyozamancave.fr"
        placeholderTextColor={Colors.textDim}
        autoCapitalize="none"
        keyboardType="url"
      />
      <Text style={LABEL}>Token</Text>
      <TextInput
        style={INPUT}
        value={giteaToken}
        onChangeText={setGiteaToken}
        placeholder="Bearer token"
        placeholderTextColor={Colors.textDim}
        secureTextEntry
        autoCapitalize="none"
      />
      <Text style={LABEL}>Owner</Text>
      <TextInput
        style={INPUT}
        value={giteaOwner}
        onChangeText={setGiteaOwner}
        placeholder="username or org"
        placeholderTextColor={Colors.textDim}
        autoCapitalize="none"
      />
      <Text style={LABEL}>Repository</Text>
      <TextInput
        style={INPUT}
        value={giteaRepo}
        onChangeText={setGiteaRepo}
        placeholder="incidents"
        placeholderTextColor={Colors.textDim}
        autoCapitalize="none"
      />

      <Text style={SECTION_TITLE}>Markdown Template</Text>
      <TextInput
        style={{ ...INPUT, minHeight: 200, textAlignVertical: "top" }}
        value={mdTemplate}
        onChangeText={setMdTemplate}
        multiline
        placeholder={DEFAULT_TEMPLATE}
        placeholderTextColor={Colors.textDim}
      />

      <Pressable
        onPress={handleSave}
        style={{
          backgroundColor: saved ? Colors.success : Colors.primary,
          borderRadius: 10,
          padding: 16,
          alignItems: "center",
          marginTop: 8,
        }}
      >
        <Text style={{ color: "#fff", fontSize: 16, fontWeight: "700" }}>
          {saved ? "Saved ✓" : "Save Settings"}
        </Text>
      </Pressable>
    </ScrollView>
  );
}