import type { Abi, AbiEvent, ExtractAbiEvent } from 'abitype'

import type { Client } from '../../clients/createClient.js'
import type { Transport } from '../../clients/transports/createTransport.js'
import {
  DecodeLogDataMismatch,
  DecodeLogTopicsMismatch,
} from '../../errors/abi.js'
import type { ErrorType } from '../../errors/utils.js'
import type { BlockNumber, BlockTag } from '../../types/block.js'
import type { Chain } from '../../types/chain.js'
import type { Filter, FilterType } from '../../types/filter.js'
import type { Log } from '../../types/log.js'
import type { Hash } from '../../types/misc.js'
import {
  type DecodeEventLogErrorType,
  decodeEventLog,
} from '../../utils/abi/decodeEventLog.js'
import type { RequestErrorType } from '../../utils/buildRequest.js'
import {
  type FormatLogErrorType,
  formatLog,
} from '../../utils/formatters/log.js'

export type GetFilterChangesParameters<
  TFilterType extends FilterType = FilterType,
  TAbi extends Abi | readonly unknown[] | undefined = undefined,
  TEventName extends string | undefined = undefined,
  TStrict extends boolean | undefined = undefined,
  TFromBlock extends BlockNumber | BlockTag | undefined = undefined,
  TToBlock extends BlockNumber | BlockTag | undefined = undefined,
> = {
  filter: Filter<
    TFilterType,
    TAbi,
    TEventName,
    any,
    TStrict,
    TFromBlock,
    TToBlock
  >
}

export type GetFilterChangesReturnType<
  TFilterType extends FilterType = FilterType,
  TAbi extends Abi | readonly unknown[] | undefined = undefined,
  TEventName extends string | undefined = undefined,
  TStrict extends boolean | undefined = undefined,
  TFromBlock extends BlockNumber | BlockTag | undefined = undefined,
  TToBlock extends BlockNumber | BlockTag | undefined = undefined,
  _AbiEvent extends AbiEvent | undefined = TAbi extends Abi
    ? TEventName extends string
      ? ExtractAbiEvent<TAbi, TEventName>
      : undefined
    : undefined,
  _Pending extends boolean =
    | (TFromBlock extends 'pending' ? true : false)
    | (TToBlock extends 'pending' ? true : false),
> = TFilterType extends 'event'
  ? Log<bigint, number, _Pending, _AbiEvent, TStrict, TAbi, TEventName>[]
  : Hash[]

export type GetFilterChangesErrorType =
  | RequestErrorType
  | DecodeEventLogErrorType
  | FormatLogErrorType
  | ErrorType

/**
 * Returns a list of logs or hashes based on a [Filter](/docs/glossary/terms#filter) since the last time it was called.
 *
 * - Docs: https://viem.sh/docs/actions/public/getFilterChanges.html
 * - JSON-RPC Methods: [`eth_getFilterChanges`](https://ethereum.org/en/developers/docs/apis/json-rpc/#eth_getfilterchanges)
 *
 * A Filter can be created from the following actions:
 *
 * - [`createBlockFilter`](https://viem.sh/docs/actions/public/createBlockFilter.html)
 * - [`createContractEventFilter`](https://viem.sh/docs/contract/createContractEventFilter.html)
 * - [`createEventFilter`](https://viem.sh/docs/actions/public/createEventFilter.html)
 * - [`createPendingTransactionFilter`](https://viem.sh/docs/actions/public/createPendingTransactionFilter.html)
 *
 * Depending on the type of filter, the return value will be different:
 *
 * - If the filter was created with `createContractEventFilter` or `createEventFilter`, it returns a list of logs.
 * - If the filter was created with `createPendingTransactionFilter`, it returns a list of transaction hashes.
 * - If the filter was created with `createBlockFilter`, it returns a list of block hashes.
 *
 * @param client - Client to use
 * @param parameters - {@link GetFilterChangesParameters}
 * @returns Logs or hashes. {@link GetFilterChangesReturnType}
 *
 * @example
 * // Blocks
 * import { createPublicClient, http } from 'viem'
 * import { mainnet } from 'viem/chains'
 * import { createBlockFilter, getFilterChanges } from 'viem/public'
 *
 * const client = createPublicClient({
 *   chain: mainnet,
 *   transport: http(),
 * })
 * const filter = await createBlockFilter(client)
 * const hashes = await getFilterChanges(client, { filter })
 *
 * @example
 * // Contract Events
 * import { createPublicClient, http, parseAbi } from 'viem'
 * import { mainnet } from 'viem/chains'
 * import { createContractEventFilter, getFilterChanges } from 'viem/public'
 *
 * const client = createPublicClient({
 *   chain: mainnet,
 *   transport: http(),
 * })
 * const filter = await createContractEventFilter(client, {
 *   address: '0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48',
 *   abi: parseAbi(['event Transfer(address indexed, address indexed, uint256)']),
 *   eventName: 'Transfer',
 * })
 * const logs = await getFilterChanges(client, { filter })
 *
 * @example
 * // Raw Events
 * import { createPublicClient, http, parseAbiItem } from 'viem'
 * import { mainnet } from 'viem/chains'
 * import { createEventFilter, getFilterChanges } from 'viem/public'
 *
 * const client = createPublicClient({
 *   chain: mainnet,
 *   transport: http(),
 * })
 * const filter = await createEventFilter(client, {
 *   address: '0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48',
 *   event: parseAbiItem('event Transfer(address indexed, address indexed, uint256)'),
 * })
 * const logs = await getFilterChanges(client, { filter })
 *
 * @example
 * // Transactions
 * import { createPublicClient, http } from 'viem'
 * import { mainnet } from 'viem/chains'
 * import { createPendingTransactionFilter, getFilterChanges } from 'viem/public'
 *
 * const client = createPublicClient({
 *   chain: mainnet,
 *   transport: http(),
 * })
 * const filter = await createPendingTransactionFilter(client)
 * const hashes = await getFilterChanges(client, { filter })
 */
export async function getFilterChanges<
  TTransport extends Transport,
  TChain extends Chain | undefined,
  TFilterType extends FilterType,
  const TAbi extends Abi | readonly unknown[] | undefined,
  TEventName extends string | undefined,
  TStrict extends boolean | undefined = undefined,
  TFromBlock extends BlockNumber | BlockTag | undefined = undefined,
  TToBlock extends BlockNumber | BlockTag | undefined = undefined,
>(
  _client: Client<TTransport, TChain>,
  {
    filter,
  }: GetFilterChangesParameters<
    TFilterType,
    TAbi,
    TEventName,
    TStrict,
    TFromBlock,
    TToBlock
  >,
): Promise<
  GetFilterChangesReturnType<
    TFilterType,
    TAbi,
    TEventName,
    TStrict,
    TFromBlock,
    TToBlock
  >
> {
  const strict = 'strict' in filter && filter.strict

  const logs = await filter.request({
    method: 'eth_getFilterChanges',
    params: [filter.id],
  })
  return logs
    .map((log) => {
      if (typeof log === 'string') return log
      try {
        const { eventName, args } =
          'abi' in filter && filter.abi
            ? decodeEventLog({
                abi: filter.abi,
                data: log.data,
                topics: log.topics as any,
                strict,
              })
            : { eventName: undefined, args: undefined }
        return formatLog(log, { args, eventName })
      } catch (err) {
        let eventName
        let isUnnamed
        if (
          err instanceof DecodeLogDataMismatch ||
          err instanceof DecodeLogTopicsMismatch
        ) {
          // If strict mode is on, and log data/topics do not match event definition, skip.
          if ('strict' in filter && filter.strict) return
          eventName = err.abiItem.name
          isUnnamed = err.abiItem.inputs?.some((x) => !('name' in x && x.name))
        }

        // Set args undefined if there is an error decoding (e.g. indexed/non-indexed params mismatch).
        return formatLog(log, { args: isUnnamed ? [] : {}, eventName })
      }
    })
    .filter(Boolean) as GetFilterChangesReturnType<
    TFilterType,
    TAbi,
    TEventName,
    TStrict,
    TFromBlock,
    TToBlock
  >
}