import { catcher, catcher_async, squish_option } from "utils";
import { Conversation, Database, Message, Preset } from "types";
import { Option } from "optionals";
import { URL } from "utils";

const DB_PATH = "./db.json";

export async function get_db_obj(): Promise<Option<Database>> {
    const text = await catcher_async(() => Deno.readTextFile(DB_PATH));
    const db = text.map(db_text =>
        catcher(() => JSON.parse(db_text) as Database)
    );
    return squish_option(db);
}

export async function get_message(id: string): Promise<Option<Message>> {
    return (await get_db_obj()).map(db => db.messages[id]);
}

export async function get_conversation(
    id: string
): Promise<Option<Conversation>> {
    return (await get_db_obj()).map(db => db.conversations[id]);
}

async function save_db(db: Database) {
    await Deno.writeTextFile(DB_PATH, JSON.stringify(db));
}

export function new_conversation(
    name: string,
    description: string
): Promise<Option<string>> {
    return catcher_async(async () => {
        const db = (await get_db_obj()).unwrap();

        const id = abc_number(db.conversation_id);
        db.conversation_id++;
        db.conversations[id] = { name, description, messages: [], presets: {} };
        db.conversations[id].presets.default = { fg: "black" };
        db.conversations[id].presets.page = { fg: "black", bg: "white" };
        db.conversations[id].presets.box = { fg: "black", bg: "white" };

        await save_db(db);
        return id;
    });
}

export function add_preset(
    name: string,
    { fg, bg, font }: Preset,
    conv_id: string
) {
    return catcher_async(async () => {
        const db = (await get_db_obj()).unwrap();
        const conv = db.conversations[conv_id];
        if (!conv.presets) {
            conv.presets = {};
        }
        conv.presets[name] = { fg, bg, font };

        await save_db(db);
        return name;
    });
}

export function orphan_message(message: Message): Promise<Option<string>> {
    return catcher_async(async () => {
        const db = (await get_db_obj()).unwrap();

        const id = abc_number(db.message_id);
        db.message_id++;
        db.messages[id] = message;

        await save_db(db);
        return id;
    });
}

export function message_under(
    message: Message,
    conv_id: string
): Promise<Option<string>> {
    return catcher_async(async () => {
        const new_msg_id = (await orphan_message(message)).unwrap();
        const db = (await get_db_obj()).unwrap();
        if (!db.conversations[conv_id]) {
            throw {};
        }
        db.conversations[conv_id].messages.push(new_msg_id);

        await save_db(db);
        return new_msg_id;
    });
}

function abc_number(n: number): string {
    let x = n.toString(26);
    for (let i = 25; i >= 0; i--) {
        const from = i.toString(26);
        const to = (i + 10).toString(36);
        x = x.replaceAll(from, to);
    }
    return x;
}

export async function fetch_db(): Promise<Option<Database>> {
    const db_response = await catcher_async(
        async () => await fetch(`${URL}/api/db`).then(r => r.json())
    );
    return db_response.map(db => db.val);
}

// export type Preset = {
//     fg: string;
//     bg: string;
//     font?: string;
// };

//TODO: AS TEMPTING AS IT MIGHT BE, DO NOT JUST HAVE A save_db FUNCTION THAT STORES A SERIALIZED OBJECT
//TODO: THAT IS JUST *BEGGING* FOR CONCURRENCY ERRORS
//TODO: INSTEAD HAVE A SMALL SET OF FUNCTIONS THAT DO SPECIFIC THINGS

//TODO: it might actually be easier to use an actual db

// toy-network on  main [✘!?] via  v17.4.0 took 1m10s
// ❯ curl --request PUT localhost:8000/api/conv -d '{"name": "test", "description": "curl test", "fg": "red", "bg": "blue"}'
// "a"⏎
// toy-network on  main [✘!?] via  v17.4.0
// ❯ curl --request PUT localhost:8000/api/conv/a -d '{"content": "hello", "font": "Comic Sans MS"}'
// {}⏎
// toy-network on  main [✘!?] via  v17.4.0
// ❯ curl --request PUT localhost:8000/api/conv/a -d '{"content": "hello", "font": "Comic Sans MS"}'
// {"val":"c"}⏎
// toy-network on  main [✘!?] via  v17.4.0
// ❯ curl --request PUT localhost:8000/api/conv/a -d '{"content": "hello", "font": "Comic Sans MS"}'
// {"val":"c"}⏎
// toy-network on  main [✘!?] via  v17.4.0
// ❯ curl --request PUT localhost:8000/api/conv/a -d '{"content": "yay", "font": "cursive", "fg": "rebeccapurple"}'
// {"val":"d"}⏎
// toy-network on  main [✘!?] via  v17.4.0
// ❯ curl --request PUT localhost:8000/api/conv/a -d '{"content": "serif", "font": "serif", "fg": "rebeccapurple"}'
// {"val":"e"}⏎
// toy-network on  main [✘!?] via  v17.4.0
// ❯ curl --request PUT localhost:8000/api/conv/a -d '{"content": "\\"normal\\"", "fg": "rebeccapurple"}'
// {"val":"f"}⏎
// toy-network on  main [✘!?] via  v17.4.0
// ❯ curl --request PUT localhost:8000/api/conv/a -d '{"content": "contrast", "bg": "black", "fg": "white"}'
// {"val":"g"}⏎