import { computed } from 'vue'
import { useNeptuneStore } from '@/stores/neptuneStore'
import * as API from '@/api/neptuneApi'
import type { GenerateSeedResult, ViewKeyResult } from '@/interface'
import initWasm, {
    generate_seed,
    get_viewkey,
    address_from_seed,
    validate_seed_phrase,
    decode_viewkey,
} from '@neptune/wasm'

let wasmInitialized = false
let initPromise: Promise<void> | null = null

export function useNeptuneWallet() {
    const store = useNeptuneStore()

    // ===== WASM METHODS =====
    const ensureWasmInitialized = async (): Promise<void> => {
        if (wasmInitialized) {
            return
        }

        if (initPromise) {
            return initPromise
        }

        initPromise = (async () => {
            try {
                store.setLoading(true)
                store.setError(null)

                await initWasm()

                wasmInitialized = true
            } catch (err) {
                wasmInitialized = false
                const errorMsg = 'Failed to initialize Neptune WASM'
                store.setError(errorMsg)
                console.error('WASM init error:', err)
                throw new Error(errorMsg)
            } finally {
                store.setLoading(false)
            }
        })()

        return initPromise
    }

    const generateWallet = async (): Promise<GenerateSeedResult> => {
        try {
            store.setLoading(true)
            store.setError(null)

            await ensureWasmInitialized()

            const resultJson = generate_seed()
            const result: GenerateSeedResult = JSON.parse(resultJson)

            store.setSeedPhrase(result.seed_phrase)
            store.setReceiverId(result.receiver_identifier)

            const viewKeyResult = await getViewKeyFromSeed(result.seed_phrase, store.getNetwork)

            store.setViewKey(viewKeyResult.view_key)
            store.setAddress(viewKeyResult.address)

            return result
        } catch (err) {
            const errorMsg = err instanceof Error ? err.message : 'Failed to generate wallet'
            store.setError(errorMsg)
            throw err
        } finally {
            store.setLoading(false)
        }
    }

    const getViewKeyFromSeed = async (
        seedPhrase: string[],
        network: 'mainnet' | 'testnet'
    ): Promise<ViewKeyResult> => {
        await ensureWasmInitialized()
        const seedPhraseJson = JSON.stringify(seedPhrase)
        const resultJson = get_viewkey(seedPhraseJson, network)
        return JSON.parse(resultJson)
    }

    const importWallet = async (
        seedPhrase: string[],
        network: 'mainnet' | 'testnet' = 'testnet'
    ): Promise<ViewKeyResult> => {
        try {
            store.setLoading(true)
            store.setError(null)

            const isValid = await validateSeedPhrase(seedPhrase)
            if (!isValid) {
                throw new Error('Invalid seed phrase')
            }

            const result = await getViewKeyFromSeed(seedPhrase, network)

            store.setSeedPhrase(seedPhrase)
            store.setReceiverId(result.receiver_identifier)
            store.setViewKey(result.view_key)
            store.setAddress(result.address)
            store.setNetwork(network)

            return result
        } catch (err) {
            const errorMsg = err instanceof Error ? err.message : 'Failed to import wallet'
            store.setError(errorMsg)
            throw err
        } finally {
            store.setLoading(false)
        }
    }

    const getAddressFromSeed = async (
        seedPhrase: string[],
        network: 'mainnet' | 'testnet'
    ): Promise<string> => {
        await ensureWasmInitialized()
        const seedPhraseJson = JSON.stringify(seedPhrase)
        return address_from_seed(seedPhraseJson, network)
    }

    const validateSeedPhrase = async (seedPhrase: string[]): Promise<boolean> => {
        try {
            await ensureWasmInitialized()
            const seedPhraseJson = JSON.stringify(seedPhrase)
            return validate_seed_phrase(seedPhraseJson)
        } catch (err) {
            console.error('Validation error:', err)
            return false
        }
    }

    const decodeViewKey = async (viewKeyHex: string): Promise<{ receiver_identifier: string }> => {
        await ensureWasmInitialized()
        const resultJson = decode_viewkey(viewKeyHex)
        return JSON.parse(resultJson)
    }

    const importFromViewKey = async (viewKeyHex: string): Promise<{ receiver_identifier: string }> => {
        try {
            store.setLoading(true)
            store.setError(null)

            const result = await decodeViewKey(viewKeyHex)

            store.setViewKey(viewKeyHex)
            store.setReceiverId(result.receiver_identifier)
            // Note: When importing from viewkey, we don't have the seed phrase
            // and address needs to be derived from viewkey
            
            return result
        } catch (err) {
            const errorMsg = err instanceof Error ? err.message : 'Failed to import from view key'
            store.setError(errorMsg)
            throw err
        } finally {
            store.setLoading(false)
        }
    }

    // ===== API METHODS =====

    const getUtxos = async (
        startBlock: number = 0,
        endBlock: number | null = null,
        maxSearchDepth: number = 1000
    ): Promise<any> => {
        try {
            if (!store.getViewKey) {
                throw new Error('No view key available. Please import or generate a wallet first.')
            }

            store.setLoading(true)
            store.setError(null)

            const response = await API.getUtxosFromViewKey(
                store.getViewKey,
                startBlock,
                endBlock,
                maxSearchDepth
            )

            const result = response.data?.result || response.data
            store.setUtxos(result.utxos || result || [])
            return result
        } catch (err) {
            const errorMsg = err instanceof Error ? err.message : 'Failed to get UTXOs'
            store.setError(errorMsg)
            throw err
        } finally {
            store.setLoading(false)
        }
    }

    const getBalance = async (): Promise<any> => {
        try {
            store.setLoading(true)
            store.setError(null)

            const response = await API.getBalance()
            const result = response.data?.result || response.data
            store.setBalance(result.balance || result)

            return result
        } catch (err) {
            const errorMsg = err instanceof Error ? err.message : 'Failed to get balance'
            store.setError(errorMsg)
            throw err
        } finally {
            store.setLoading(false)
        }
    }

    const getBlockHeight = async (): Promise<any> => {
        try {
            store.setLoading(true)
            store.setError(null)

            const response = await API.getBlockHeight()
            const result = response.data?.result || response.data
            return result.height || result
        } catch (err) {
            const errorMsg = err instanceof Error ? err.message : 'Failed to get block height'
            store.setError(errorMsg)
            throw err
        } finally {
            store.setLoading(false)
        }
    }

    const getNetworkInfo = async (): Promise<any> => {
        try {
            store.setLoading(true)
            store.setError(null)

            const response = await API.getNetworkInfo()
            const result = response.data?.result || response.data
            return result
        } catch (err) {
            const errorMsg = err instanceof Error ? err.message : 'Failed to get network info'
            store.setError(errorMsg)
            throw err
        } finally {
            store.setLoading(false)
        }
    }

    const sendTransaction = async (
        toAddress: string,
        amount: string,
        fee: string
    ): Promise<any> => {
        try {
            store.setLoading(true)
            store.setError(null)

            const response = await API.sendTransaction(toAddress, amount, fee)
            const result = response.data?.result || response.data
            return result
        } catch (err) {
            const errorMsg = err instanceof Error ? err.message : 'Failed to send transaction'
            store.setError(errorMsg)
            throw err
        } finally {
            store.setLoading(false)
        }
    }

    const setNetwork = async (network: 'mainnet' | 'testnet') => {
        store.setNetwork(network)

        if (store.getSeedPhrase) {
            const viewKeyResult = await getViewKeyFromSeed(store.getSeedPhrase, network)
            store.setAddress(viewKeyResult.address)
            store.setViewKey(viewKeyResult.view_key)
        }
    }

    // ===== UTILITY METHODS =====
    const clearWallet = () => {
        store.clearWallet()
    }

    return {
        walletState: computed(() => store.getWallet),
        isLoading: computed(() => store.getLoading),
        error: computed(() => store.getError),
        hasWallet: computed(() => store.hasWallet),

        initWasm: ensureWasmInitialized,
        generateWallet,
        importWallet,
        importFromViewKey,
        getViewKeyFromSeed,
        getAddressFromSeed,
        validateSeedPhrase,
        decodeViewKey,

        getUtxos,
        getBalance,
        getBlockHeight,
        getNetworkInfo,
        sendTransaction,

        clearWallet,
        setNetwork,
    }
}