#!/usr/bin/env node

import { readFileSync } from "node:fs";
import { createClient } from "@supabase/supabase-js";
import { z } from "zod";

const SOURCE = "unsplash-wallpapers";
const DEFAULT_PAGE = 1;
const DEFAULT_PER_PAGE = 20;
const UNSPLASH_WALLPAPERS_URL =
    "https://api.unsplash.com/topics/wallpapers/photos";

const env = loadEnvLocal();

const photoSchema = z
    .object({
        id: z.string(),
        slug: z.string().nullish(),
        description: z.string().nullish(),
        alt_description: z.string().nullish(),
        width: z.number().int().nullish(),
        height: z.number().int().nullish(),
        color: z.string().nullish(),
        blur_hash: z.string().nullish(),
        likes: z.number().int().nullish(),
        created_at: z.string().nullish(),
        updated_at: z.string().nullish(),
        urls: z.record(z.string(), z.unknown()).nullish(),
        links: z.record(z.string(), z.unknown()).nullish(),
        user: z.record(z.string(), z.unknown()).nullish(),
    })
    .passthrough();

function loadEnvLocal() {
    const envMap = { ...process.env };

    try {
        const file = readFileSync(".env.local", "utf8");

        for (const line of file.split(/\r?\n/)) {
            const trimmed = line.trim();

            if (!trimmed || trimmed.startsWith("#") || !trimmed.includes("=")) {
                continue;
            }

            const [key, ...valueParts] = trimmed.split("=");
            const value = valueParts.join("=").trim();
            envMap[key.trim()] = value.replace(/^["']|["']$/g, "");
        }
    } catch {
        // Environment variables can also be provided by the process manager.
    }

    return envMap;
}

function requireEnv(key) {
    const value = env[key];

    if (!value) {
        throw new Error(`${key} is not configured.`);
    }

    return value;
}

function normalizeDate(value) {
    if (!value) {
        return null;
    }

    const date = new Date(value);
    return Number.isNaN(date.getTime()) ? null : date.toISOString();
}

function getColorFamily(color) {
    if (!color) {
        return null;
    }

    const normalized = color.trim().replace(/^#/, "");

    if (!/^[0-9a-f]{6}$/i.test(normalized)) {
        return null;
    }

    const r = parseInt(normalized.slice(0, 2), 16);
    const g = parseInt(normalized.slice(2, 4), 16);
    const b = parseInt(normalized.slice(4, 6), 16);
    const max = Math.max(r, g, b);
    const min = Math.min(r, g, b);
    const lightness = (max + min) / 510;

    if (lightness > 0.78) {
        return "light";
    }
    if (lightness < 0.2) {
        return "black";
    }

    const delta = max - min;

    if (delta < 24) {
        return lightness > 0.52 ? "light" : "black";
    }

    let hue = 0;

    if (max === r) {
        hue = ((g - b) / delta) % 6;
    } else if (max === g) {
        hue = (b - r) / delta + 2;
    } else {
        hue = (r - g) / delta + 4;
    }

    hue = Math.round(hue * 60);

    if (hue < 0) {
        hue += 360;
    }

    if (hue < 18 || hue >= 345) {
        return "red";
    }
    if (hue < 45) {
        return "orange";
    }
    if (hue < 70) {
        return "yellow";
    }
    if (hue < 170) {
        return "green";
    }
    if (hue < 255) {
        return "blue";
    }
    if (hue < 345) {
        return "purple";
    }

    return null;
}

function mapPhotoToRow(photo) {
    return {
        unsplash_id: photo.id,
        slug: photo.slug ?? null,
        description: photo.description ?? null,
        alt_description: photo.alt_description ?? null,
        width: photo.width ?? null,
        height: photo.height ?? null,
        color: photo.color ?? null,
        color_family: getColorFamily(photo.color),
        blur_hash: photo.blur_hash ?? null,
        likes: photo.likes ?? null,
        photo_created_at: normalizeDate(photo.created_at),
        photo_updated_at: normalizeDate(photo.updated_at),
        urls: photo.urls ?? {},
        links: photo.links ?? {},
        user_info: photo.user ?? {},
        raw: photo,
        source: SOURCE,
    };
}

async function fetchPhotos({ page, perPage }) {
    const accessKey = requireEnv("UNSPLASH_ACCESS_KEY");
    const url = new URL(UNSPLASH_WALLPAPERS_URL);
    url.searchParams.set("page", String(page));
    url.searchParams.set("per_page", String(perPage));

    const response = await fetch(url, {
        headers: {
            accept: "application/json",
            authorization: `Client-ID ${accessKey}`,
            "user-agent": "WalloraGallerySync/1.0",
        },
        method: "GET",
    });

    const contentType = response.headers.get("content-type") ?? "";
    if (!response.ok) {
        throw new Error(`Unsplash API request failed with ${response.status}.`);
    }

    if (!contentType.includes("application/json")) {
        throw new Error(
            `Unsplash returned non-JSON content: ${contentType || "unknown"}.`,
        );
    }

    const parsed = z.array(photoSchema).safeParse(await response.json());

    if (!parsed.success) {
        throw new Error("Unsplash response did not match the expected array.");
    }

    return parsed.data;
}

async function main() {
    const supabase = createClient(
        requireEnv("NEXT_PUBLIC_SUPABASE_URL"),
        requireEnv("SUPABASE_SERVICE_ROLE_KEY"),
        {
            auth: {
                persistSession: false,
                autoRefreshToken: false,
            },
        },
    );

    const { data: state, error: stateError } = await supabase
        .from("wg_gallery_sync_state")
        .select("source,next_page,per_page")
        .eq("source", SOURCE)
        .maybeSingle();

    if (stateError) {
        throw stateError;
    }

    const page = state?.next_page ?? DEFAULT_PAGE;
    const perPage = state?.per_page ?? DEFAULT_PER_PAGE;

    try {
        const photos = await fetchPhotos({ page, perPage });
        const rows = photos.map(mapPhotoToRow);
        let insertedCount = 0;

        if (rows.length > 0) {
            const { data, error } = await supabase
                .from("wg_gallery_photos")
                .upsert(rows, {
                    onConflict: "unsplash_id",
                    ignoreDuplicates: true,
                })
                .select("unsplash_id");

            if (error) {
                throw error;
            }

            insertedCount = data?.length ?? 0;
        }

        const nextPage = rows.length === 0 ? DEFAULT_PAGE : page + 1;
        const { error: updateError } = await supabase
            .from("wg_gallery_sync_state")
            .upsert(
                {
                    source: SOURCE,
                    next_page: nextPage,
                    per_page: perPage,
                    last_synced_at: new Date().toISOString(),
                    last_inserted_count: insertedCount,
                    last_seen_count: photos.length,
                    last_error: null,
                },
                { onConflict: "source" },
            );

        if (updateError) {
            throw updateError;
        }

        console.log(
            JSON.stringify({
                ok: true,
                source: SOURCE,
                page,
                nextPage,
                seenCount: photos.length,
                insertedCount,
            }),
        );
    } catch (error) {
        const message =
            error instanceof Error ? error.message : "Unknown sync error.";

        await supabase.from("wg_gallery_sync_state").upsert(
            {
                source: SOURCE,
                next_page: page,
                per_page: perPage,
                last_synced_at: new Date().toISOString(),
                last_inserted_count: 0,
                last_seen_count: 0,
                last_error: message,
            },
            { onConflict: "source" },
        );

        throw error;
    }
}

main().catch((error) => {
    console.error(error);
    process.exitCode = 1;
});