import type { Abi } from 'abitype'
import type { Error, Filter } from './types.js'
import { isStructSignature } from './runtime/signatures.js'
import { parseStructs } from './runtime/structs.js'
import { parseSignature } from './runtime/utils.js'
import type { Signatures } from './types/signatures.js'
import type { ParseStructs } from './types/structs.js'
import type { ParseSignature } from './types/utils.js'

/**
 * Parses human-readable ABI into JSON `Abi`.
 *
 * @param signatures - Human-readable ABI
 * @returns Parsed `Abi`.
 */
export type ParseAbi<signatures extends readonly string[]> =
  string[] extends signatures
    ? Abi // If `T` was not able to be inferred (e.g. just `string[]`), return `Abi`
    : signatures extends readonly string[]
      ? signatures extends Signatures<signatures> // Validate signatures
        ? ParseStructs<signatures> extends infer structs
          ? {
              [key in keyof signatures]: signatures[key] extends string
                ? ParseSignature<signatures[key], structs>
                : never
            } extends infer mapped extends readonly unknown[]
            ? Filter<mapped, never> extends infer result
              ? result extends readonly []
                ? never
                : result
              : never
            : never
          : never
        : never
      : never

/**
 * Parses human-readable ABI into JSON `Abi`.
 *
 * @param signatures - Human-Readable ABI
 * @returns Parsed `Abi`.
 */
export function parseAbi<const signatures extends readonly string[]>(
  signatures: signatures['length'] extends 0
    ? Error<'At least one signature required'>
    : Signatures<signatures> extends signatures
      ? signatures
      : Signatures<signatures>,
): ParseAbi<signatures> {
  const structs = parseStructs(signatures as readonly string[])
  const abi = []
  const length = signatures.length as number
  for (let i = 0; i < length; i++) {
    const signature = (signatures as readonly string[])[i]!
    if (isStructSignature(signature)) continue
    abi.push(parseSignature(signature, structs))
  }
  return abi as unknown as ParseAbi<signatures>
}