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

const KEYS = {
  INPUT_MODE: "pref_input_mode",
  HOME_VIEW: "pref_home_view",
  AI_ENABLED: "pref_ai_enabled",
  AI_KEY: "pref_ai_key",
  MD_TEMPLATE: "md_template",
  GIT_PROVIDER: "git_provider",
  // Gitea
  GITEA_URL: "gitea_url",
  GITEA_TOKEN: "gitea_token",
  GITEA_OWNER: "gitea_owner",
  GITEA_REPO: "gitea_repo",
  // GitHub
  GITHUB_TOKEN: "github_token",
  GITHUB_OWNER: "github_owner",
  GITHUB_REPO: "github_repo",
  // GitLab
  GITLAB_URL: "gitlab_url",
  GITLAB_TOKEN: "gitlab_token",
  GITLAB_OWNER: "gitlab_owner",
  GITLAB_REPO: "gitlab_repo",
} 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;

const PROVIDER_LABELS: Record<GitProvider, string> = {
  gitea: "Gitea",
  github: "GitHub",
  gitlab: "GitLab",
};

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 [mdTemplate, setMdTemplate] = useState(DEFAULT_TEMPLATE);
  const [saved, setSaved] = useState(false);

  // Git provider
  const [gitProvider, setGitProvider] = useState<GitProvider>("gitea");
  // Gitea
  const [giteaUrl, setGiteaUrl] = useState("");
  const [giteaToken, setGiteaToken] = useState("");
  const [giteaOwner, setGiteaOwner] = useState("");
  const [giteaRepo, setGiteaRepo] = useState("");
  // GitHub
  const [githubToken, setGithubToken] = useState("");
  const [githubOwner, setGithubOwner] = useState("");
  const [githubRepo, setGithubRepo] = useState("");
  // GitLab
  const [gitlabUrl, setGitlabUrl] = useState("");
  const [gitlabToken, setGitlabToken] = useState("");
  const [gitlabOwner, setGitlabOwner] = useState("");
  const [gitlabRepo, setGitlabRepo] = useState("");

  useEffect(() => {
    (async () => {
      const [im, hv, ai, key, tpl, gp, gu, gt, go, gr, ghu, ghown, ghrepo, glu, glt, glo, glr] =
        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.MD_TEMPLATE),
          SecureStore.getItemAsync(KEYS.GIT_PROVIDER),
          SecureStore.getItemAsync(KEYS.GITEA_URL),
          SecureStore.getItemAsync(KEYS.GITEA_TOKEN),
          SecureStore.getItemAsync(KEYS.GITEA_OWNER),
          SecureStore.getItemAsync(KEYS.GITEA_REPO),
          SecureStore.getItemAsync(KEYS.GITHUB_TOKEN),
          SecureStore.getItemAsync(KEYS.GITHUB_OWNER),
          SecureStore.getItemAsync(KEYS.GITHUB_REPO),
          SecureStore.getItemAsync(KEYS.GITLAB_URL),
          SecureStore.getItemAsync(KEYS.GITLAB_TOKEN),
          SecureStore.getItemAsync(KEYS.GITLAB_OWNER),
          SecureStore.getItemAsync(KEYS.GITLAB_REPO),
        ]);
      if (im) setInputMode(im as "voice" | "form");
      if (hv) setHomeView(hv as "dashboard" | "capture");
      if (ai) setAiEnabled(ai === "true");
      if (key) setAiKey(key);
      if (tpl) setMdTemplate(tpl);
      if (gp) setGitProvider(gp as GitProvider);
      if (gu) setGiteaUrl(gu);
      if (gt) setGiteaToken(gt);
      if (go) setGiteaOwner(go);
      if (gr) setGiteaRepo(gr);
      if (ghu) setGithubToken(ghu);
      if (ghown) setGithubOwner(ghown);
      if (ghrepo) setGithubRepo(ghrepo);
      if (glu) setGitlabUrl(glu);
      if (glt) setGitlabToken(glt);
      if (glo) setGitlabOwner(glo);
      if (glr) setGitlabRepo(glr);
    })();
  }, []);

  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.MD_TEMPLATE, mdTemplate),
      SecureStore.setItemAsync(KEYS.GIT_PROVIDER, gitProvider),
      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.GITHUB_TOKEN, githubToken),
      SecureStore.setItemAsync(KEYS.GITHUB_OWNER, githubOwner),
      SecureStore.setItemAsync(KEYS.GITHUB_REPO, githubRepo),
      SecureStore.setItemAsync(KEYS.GITLAB_URL, gitlabUrl),
      SecureStore.setItemAsync(KEYS.GITLAB_TOKEN, gitlabToken),
      SecureStore.setItemAsync(KEYS.GITLAB_OWNER, gitlabOwner),
      SecureStore.setItemAsync(KEYS.GITLAB_REPO, gitlabRepo),
    ]);
    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 ? Colors.bg : Colors.text2,
                  fontWeight: "700",
                  fontSize: 13,
                }}
              >
                {opt.label}
              </Text>
            </Pressable>
          ))}
        </View>
      </View>
    );
  }

  function Field({
    label,
    value,
    onChange,
    placeholder,
    secure,
    url,
  }: {
    label: string;
    value: string;
    onChange: (v: string) => void;
    placeholder?: string;
    secure?: boolean;
    url?: boolean;
  }) {
    return (
      <>
        <Text style={LABEL}>{label}</Text>
        <TextInput
          style={INPUT}
          value={value}
          onChangeText={onChange}
          placeholder={placeholder}
          placeholderTextColor={Colors.textDim}
          secureTextEntry={secure}
          autoCapitalize="none"
          keyboardType={url ? "url" : "default"}
        />
      </>
    );
  }

  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 && (
        <Field
          label="API Key"
          value={aiKey}
          onChange={setAiKey}
          placeholder="sk-..."
          secure
        />
      )}

      <Text style={SECTION_TITLE}>Git Repository</Text>

      <SegmentRow
        label="Provider"
        value={gitProvider}
        onChange={(v) => setGitProvider(v as GitProvider)}
        options={(["gitea", "github", "gitlab"] as GitProvider[]).map((p) => ({
          key: p,
          label: PROVIDER_LABELS[p],
        }))}
      />

      {gitProvider === "gitea" && (
        <>
          <Field
            label="Instance URL"
            value={giteaUrl}
            onChange={setGiteaUrl}
            placeholder="https://homegit.example.com"
            url
          />
          <Field
            label="Token"
            value={giteaToken}
            onChange={setGiteaToken}
            placeholder="Bearer token"
            secure
          />
          <Field
            label="Owner"
            value={giteaOwner}
            onChange={setGiteaOwner}
            placeholder="username or org"
          />
          <Field
            label="Repository"
            value={giteaRepo}
            onChange={setGiteaRepo}
            placeholder="incidents"
          />
        </>
      )}

      {gitProvider === "github" && (
        <>
          <View
            style={{
              backgroundColor: Colors.surface,
              borderRadius: 8,
              padding: 12,
              marginBottom: 14,
              borderLeftWidth: 3,
              borderLeftColor: Colors.primary,
            }}
          >
            <Text style={{ color: Colors.text2, fontSize: 13 }}>
              Uses api.github.com — no instance URL required.
            </Text>
          </View>
          <Field
            label="Personal Access Token"
            value={githubToken}
            onChange={setGithubToken}
            placeholder="ghp_..."
            secure
          />
          <Field
            label="Owner (username or org)"
            value={githubOwner}
            onChange={setGithubOwner}
            placeholder="your-username"
          />
          <Field
            label="Repository"
            value={githubRepo}
            onChange={setGithubRepo}
            placeholder="incidents"
          />
        </>
      )}

      {gitProvider === "gitlab" && (
        <>
          <Field
            label="Instance URL"
            value={gitlabUrl}
            onChange={setGitlabUrl}
            placeholder="https://gitlab.com"
            url
          />
          <Field
            label="Personal Access Token"
            value={gitlabToken}
            onChange={setGitlabToken}
            placeholder="glpat-..."
            secure
          />
          <Field
            label="Namespace (user or group)"
            value={gitlabOwner}
            onChange={setGitlabOwner}
            placeholder="your-username"
          />
          <Field
            label="Repository"
            value={gitlabRepo}
            onChange={setGitlabRepo}
            placeholder="incidents"
          />
        </>
      )}

      <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: Colors.bg, fontSize: 16, fontWeight: "700" }}>
          {saved ? "Saved ✓" : "Save Settings"}
        </Text>
      </Pressable>
    </ScrollView>
  );
}