import { schema } from '#triplit/schema';
import { type Entity } from '@triplit/client';
import { computed, watch, ref, type Ref } from 'vue';

type UserSettings = Entity<typeof schema, 'settings'>;

interface UserSettingsState {
    accent: Ref<string>;
    neutral: Ref<string>;
    hinting: Ref<string>;
    colorSchemePreference: Ref<'light' | 'dark' | 'system'>;
    colorSchemeClass: Ref<'light' | 'dark' | undefined>;
    remoteSettings: Ref<UserSettings | null>;
    initPromise: Promise<void> | null;
}

export const useUserSettings = () => {
    const nuxtApp = useNuxtApp();
    const triplit = useTriplitClient();
    const { user, loggedIn } = useAuth();

    if (!nuxtApp._userSettingsState) {
        nuxtApp._userSettingsState = {
            accent: ref('violet'),
            neutral: ref('zinc'),
            hinting: ref('0'),
            colorSchemePreference: ref<'light' | 'dark' | 'system'>('system'),
            colorSchemeClass: ref<undefined | 'light' | 'dark'>(undefined),
            remoteSettings: ref<UserSettings | null>(null),
            initPromise: null,
        } as UserSettingsState;
    }

    const state = nuxtApp._userSettingsState as UserSettingsState;

    const init = (): Promise<void> => {
        if (state.initPromise) return state.initPromise;

        state.initPromise = (async () => {
            const { results } = await useQuery('settings', triplit, triplit.query('settings'));

            watch(results, (val) => {
                if (val && val.length > 0) {
                    state.remoteSettings.value = val[0] as UserSettings;
                } else {
                    state.remoteSettings.value = null;
                }
            }, { immediate: true, deep: true });

            watch(state.remoteSettings, (newSettings) => {
                if (!newSettings?.appearance) return;
                const { appearance } = newSettings;

                if (appearance.colorScheme) {
                    state.colorSchemePreference.value = appearance.colorScheme as 'light' | 'dark' | 'system';
                }
                if (appearance.accent) {
                    state.accent.value = appearance.accent;
                }
                if (appearance.neutral) {
                    state.neutral.value = appearance.neutral;
                }
                if (appearance.hinting !== undefined) {
                    state.hinting.value = String(appearance.hinting);
                }
            }, { immediate: true, deep: true });

            if (import.meta.client) {
                const mediaQuery = window.matchMedia('(prefers-color-scheme: dark)');
                const update = () => {
                    if (state.colorSchemePreference.value === 'system') {
                        state.colorSchemeClass.value = mediaQuery.matches ? 'dark' : 'light';
                    } else {
                        state.colorSchemeClass.value = state.colorSchemePreference.value as 'dark' | 'light';
                    }
                };
                mediaQuery.addEventListener('change', update);
                watch(state.colorSchemePreference, update, { immediate: true });
            } else {
                watch(state.colorSchemePreference, (pref) => {
                    state.colorSchemeClass.value = pref === 'system' ? 'dark' : (pref as 'dark' | 'light');
                }, { immediate: true });
            }
        })();

        return state.initPromise;
    };

    const colorSchemeValue = computed(() => {
        if (state.colorSchemePreference.value === 'system') {
            if (import.meta.client) {
                return window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light';
            }
            return 'dark';
        }
        return state.colorSchemePreference.value as 'dark' | 'light';
    });

    const settings = computed(() => {
        const remote = state.remoteSettings.value;
        return {
            appearance: {
                colorScheme: remote?.appearance?.colorScheme ?? state.colorSchemePreference.value,
                accent: remote?.appearance?.accent ?? state.accent.value,
                neutral: remote?.appearance?.neutral ?? state.neutral.value,
                hinting: remote?.appearance?.hinting ?? Number(state.hinting.value),
                fontSize: remote?.appearance?.fontSize ?? 'medium',
            },
            systemAssistants: {
                rename: {
                    enabled: remote?.systemAssistants?.rename?.enabled ?? false,
                    prompt: remote?.systemAssistants?.rename?.prompt ?? null,
                    modelId: remote?.systemAssistants?.rename?.modelId ?? null,
                }
            }
        };
    });

    const updateSettings = async (updates: {
        appearance?: {
            colorScheme?: 'light' | 'dark' | 'system';
            accent?: string;
            neutral?: string;
            hinting?: number;
            fontSize?: string;
        };
        systemAssistants?: {
            rename?: {
                enabled?: boolean;
                prompt?: string | null;
                modelId?: string | null;
            };
        };
    }) => {
        if (updates.appearance) {
            if (updates.appearance.colorScheme) state.colorSchemePreference.value = updates.appearance.colorScheme;
            if (updates.appearance.accent) state.accent.value = updates.appearance.accent;
            if (updates.appearance.neutral) state.neutral.value = updates.appearance.neutral;
            if (updates.appearance.hinting !== undefined) state.hinting.value = String(updates.appearance.hinting);
        }

        if (!loggedIn.value || !user.value?.id) return;

        const current = state.remoteSettings.value;
        if (!current) {
            await triplit.insert('settings', {
                userId: user.value.id,
                appearance: {
                    colorScheme: state.colorSchemePreference.value,
                    accent: state.accent.value,
                    neutral: state.neutral.value,
                    hinting: Number(state.hinting.value),
                    ...(updates.appearance || {})
                },
                systemAssistants: {
                    rename: {
                        enabled: updates.systemAssistants?.rename?.enabled ?? true,
                        prompt: updates.systemAssistants?.rename?.prompt ?? null,
                        modelId: updates.systemAssistants?.rename?.modelId ?? null,
                    }
                }
            });
            return;
        }

        await triplit.update('settings', current.id, (s) => {
            if (updates.appearance) {
                s.appearance = {
                    ...(s.appearance || {}),
                    ...updates.appearance
                };
            }
            if (updates.systemAssistants) {
                // @ts-expect-error
                s.systemAssistants = {
                    ...(s.systemAssistants || {}),
                    ...updates.systemAssistants
                };
            }
        });
    };

    return {
        init,
        settings,
        remoteSettings: state.remoteSettings,
        updateSettings,
        accent: state.accent,
        neutral: state.neutral,
        hinting: state.hinting,
        colorScheme: {
            preference: state.colorSchemePreference,
            value: colorSchemeValue,
            class: state.colorSchemeClass
        }
    };
};