import type * as pg from "npm:pg";
import { strToBool } from "../utils/convert.ts";
import { BadConfigErr } from "../utils/errors.ts";
import { readJsonFileSync } from "../utils/io.ts";
import * as path from "jsr:@std/path";

export const POSTGRES_PASSWORD        = "POSTGRES_PASSWORD"
export const MIC_APPLY_MIGRATIONS     = "MIC_APPLY_MIGRATIONS"
export const DEFAULT_CONFIG_FILE_PATH = import.meta.dirname ? path.join(import.meta.dirname, '../config.json') : '/app/config.json'
export const MIC_DROP_DB              = "MIC_DROP_DB"
export const BOT_TOKEN                = "BOT_TOKEN"
export const MIC_CONFIG_PATH          = "MIC_CONFIG_PATH"

export enum BotMode{ setup, normal }
export type BotConfig = {
  mode: BotMode,
  bot_token: string,
  chat_id: number,
  admin_ids: number[],
}

export interface EnvConfig {
    db_password?:         string,
    bot_token?:           string,
    mic_config_path?:     string,
    mic_apply_migrations: boolean,
    mic_drop_db:          boolean,
}

export interface FileConfig {
    db_user?:          string,
    db_name?:          string,
    db_port?:          number,
    db_host?:          string,
    db_tls?:           boolean,
    db_password_file?: string,
    bot_token?:        string,
}

export interface Config {
    db_user?:         string,
    db_name?:         string,
    db_port?:         number,
    db_host?:         string,
    db_tls?:          boolean,
    db_password:      string,
    bot_token:        string,
    config_path:      string,
    apply_migrations: boolean,
    drop_db:          boolean,
}

export interface MigrationConfig {
    dropDb:          boolean
    applyMigrations: boolean
    migrationsPath:  string
}

export interface CompiledConfig {
    pgPoolCfg:     pg.PoolConfig
    botCfg:        BotConfig
    migrationCfg?: MigrationConfig
}

export const getEnvConfig = (): EnvConfig => {
    const apply_migrations =
        strToBool(Deno.env.get(MIC_APPLY_MIGRATIONS) || "n") || false
    if (apply_migrations) Deno.env.set(MIC_APPLY_MIGRATIONS, "n") 

    const drop_db = strToBool(Deno.env.get(MIC_DROP_DB) || "n") || false
    if (drop_db) Deno.env.set(MIC_DROP_DB, "n")

    return {
        db_password:          Deno.env.get(POSTGRES_PASSWORD),
        bot_token:            Deno.env.get(BOT_TOKEN),
        mic_config_path:      Deno.env.get(MIC_CONFIG_PATH),
        mic_apply_migrations: apply_migrations,
        mic_drop_db:          drop_db,
    }
}

export const getConfig = (): Config => {
    const envCfg = getEnvConfig()
    const config_path = envCfg.mic_config_path || DEFAULT_CONFIG_FILE_PATH
    const fileCfg = readJsonFileSync<FileConfig>(config_path)

    let db_password: string;
    if (fileCfg.db_password_file) {
        const decoder = new TextDecoder("utf-8")
        const data = Deno.readFileSync(fileCfg.db_password_file)
        db_password = decoder.decode(data).toString()
        if (db_password[db_password.length - 1] === '\n') {
          db_password = db_password.slice(0, -1)
        }
    } else if (envCfg.db_password) {
        db_password = envCfg.db_password
    } else throw new BadConfigErr(
        "Expected db_password_file to be set in the config "+
        "or the POSTGRES_PASSWORD environment variable, "+
        "but bot both are undefined. "+
        "Check the Config section in README.md"
    )

    const bot_token: string | undefined = envCfg.bot_token || fileCfg.bot_token
    if (!bot_token) throw new BadConfigErr(
        "Expected bot_token to be set in the config "+
        "or at the BOT_TOKEN environment variable, "+
        "but bot token is undefined. "+
        "Check the Config section in README.md"
    )

    return {
        db_host: fileCfg.db_host,
        db_user: fileCfg.db_user,
        db_name: fileCfg.db_name,
        db_port: fileCfg.db_port,
        db_tls:  fileCfg.db_tls,
        db_password,
        config_path,
        apply_migrations: envCfg.mic_apply_migrations,
        drop_db: envCfg.mic_drop_db,

        bot_token,
    }
}