// file: kb_lib/src/dex/dexlab.rs

//! DexLab Swap/Pool transaction decoder.

/// Decoded DexLab create-pool event.
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
pub struct DexlabCreatePoolDecoded {
    /// Parent transaction id.
    pub transaction_id: i64,
    /// Parent instruction id.
    pub instruction_id: i64,
    /// Transaction signature.
    pub signature: std::string::String,
    /// Program id.
    pub program_id: std::string::String,
    /// Optional pool account.
    pub pool_account: std::option::Option<std::string::String>,
    /// Optional token A mint.
    pub token_a_mint: std::option::Option<std::string::String>,
    /// Optional token B mint.
    pub token_b_mint: std::option::Option<std::string::String>,
    /// Optional creator / payer.
    pub creator: std::option::Option<std::string::String>,
    /// Optional fee tier representation.
    pub fee_tier: std::option::Option<std::string::String>,
    /// Decoded payload.
    pub payload_json: serde_json::Value,
}

/// Decoded DexLab swap event.
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
pub struct DexlabSwapDecoded {
    /// Parent transaction id.
    pub transaction_id: i64,
    /// Parent instruction id.
    pub instruction_id: i64,
    /// Transaction signature.
    pub signature: std::string::String,
    /// Program id.
    pub program_id: std::string::String,
    /// Trade side relative to normalized base.
    pub trade_side: crate::SwapTradeSide,
    /// Optional pool account.
    pub pool_account: std::option::Option<std::string::String>,
    /// Optional token A mint.
    pub token_a_mint: std::option::Option<std::string::String>,
    /// Optional token B mint.
    pub token_b_mint: std::option::Option<std::string::String>,
    /// Decoded payload.
    pub payload_json: serde_json::Value,
}

/// Decoded DexLab event.
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
pub enum DexlabDecodedEvent {
    /// Pool creation.
    CreatePool(DexlabCreatePoolDecoded),
    /// Swap.
    Swap(DexlabSwapDecoded),
}

/// DexLab decoder.
#[derive(Debug, Clone, Default)]
pub struct DexlabDecoder;

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum DexlabInstructionKind {
    CreatePool,
    Swap,
    Unknown,
}

impl DexlabDecoder {
    /// Creates a new decoder.
    pub fn new() -> Self {
        return Self;
    }

    /// Decodes one projected transaction into zero or more DexLab events.
    pub fn decode_transaction(
        &self,
        transaction: &crate::ChainTransactionDto,
        instructions: &[crate::ChainInstructionDto],
    ) -> Result<std::vec::Vec<crate::DexlabDecodedEvent>, crate::Error> {
        let transaction_id_option = transaction.id;
        let transaction_id = match transaction_id_option {
            Some(transaction_id) => transaction_id,
            None => {
                return Err(crate::Error::InvalidState(format!(
                    "chain transaction '{}' has no internal id",
                    transaction.signature
                )));
            },
        };
        let transaction_json_result =
            serde_json::from_str::<serde_json::Value>(transaction.transaction_json.as_str());
        let transaction_json = match transaction_json_result {
            Ok(transaction_json) => transaction_json,
            Err(error) => {
                return Err(crate::Error::Json(format!(
                    "cannot parse transaction_json for signature '{}': {}",
                    transaction.signature, error
                )));
            },
        };
        let log_messages = extract_log_messages(&transaction_json);
        let mut decoded_events = std::vec::Vec::new();
        for instruction in instructions {
            if instruction.parent_instruction_id.is_some() {
                continue;
            }
            let program_id_option = &instruction.program_id;
            let program_id = match program_id_option {
                Some(program_id) => program_id,
                None => continue,
            };
            if program_id.as_str() != crate::DEXLAB_PROGRAM_ID {
                continue;
            }
            let instruction_id_option = instruction.id;
            let instruction_id = match instruction_id_option {
                Some(instruction_id) => instruction_id,
                None => continue,
            };
            let accounts_result = parse_accounts_json(instruction.accounts_json.as_str());
            let accounts = match accounts_result {
                Ok(accounts) => accounts,
                Err(error) => return Err(error),
            };
            let parsed_json_result = parse_optional_parsed_json(instruction.parsed_json.as_ref());
            let parsed_json = match parsed_json_result {
                Ok(parsed_json) => parsed_json,
                Err(error) => return Err(error),
            };
            let instruction_kind = classify_instruction_kind(parsed_json.as_ref(), &log_messages);
            let pool_account = extract_string_by_candidate_keys(
                parsed_json.as_ref(),
                &["pool", "poolAddress", "poolAccount", "amm", "ammPool", "poolState"],
            )
            .or_else(|| return extract_account(&accounts, 0));
            let token_a_mint = extract_string_by_candidate_keys(
                parsed_json.as_ref(),
                &["tokenA", "tokenAMint", "mintA", "baseMint", "token0Mint", "mint0"],
            )
            .or_else(|| return extract_account(&accounts, 1));
            let token_b_mint = extract_string_by_candidate_keys(
                parsed_json.as_ref(),
                &["tokenB", "tokenBMint", "mintB", "quoteMint", "token1Mint", "mint1"],
            )
            .or_else(|| return extract_account(&accounts, 2));
            let creator = extract_string_by_candidate_keys(
                parsed_json.as_ref(),
                &["payer", "creator", "user", "owner"],
            )
            .or_else(|| return extract_account(&accounts, 3));
            let fee_tier = extract_string_by_candidate_keys(
                parsed_json.as_ref(),
                &["feeTier", "fee_tier", "tradeFeeTier", "feeRate"],
            );
            if instruction_kind == DexlabInstructionKind::CreatePool {
                let payload_json = serde_json::json!({
                    "decoder": "dexlab",
                    "eventKind": "create_pool",
                    "signature": transaction.signature,
                    "instructionId": instruction_id,
                    "instructionIndex": instruction.instruction_index,
                    "accounts": accounts,
                    "parsed": parsed_json,
                    "logMessages": log_messages,
                    "poolAccount": pool_account,
                    "tokenAMint": token_a_mint,
                    "tokenBMint": token_b_mint,
                    "creator": creator,
                    "feeTier": fee_tier
                });
                decoded_events.push(crate::DexlabDecodedEvent::CreatePool(
                    crate::DexlabCreatePoolDecoded {
                        transaction_id,
                        instruction_id,
                        signature: transaction.signature.clone(),
                        program_id: program_id.clone(),
                        pool_account,
                        token_a_mint,
                        token_b_mint,
                        creator,
                        fee_tier,
                        payload_json,
                    },
                ));
                continue;
            }
            if instruction_kind == DexlabInstructionKind::Swap {
                let trade_side = infer_trade_side(&log_messages);
                let payload_json = serde_json::json!({
                    "decoder": "dexlab",
                    "eventKind": "swap",
                    "signature": transaction.signature,
                    "instructionId": instruction_id,
                    "instructionIndex": instruction.instruction_index,
                    "accounts": accounts,
                    "parsed": parsed_json,
                    "logMessages": log_messages,
                    "poolAccount": pool_account,
                    "tokenAMint": token_a_mint,
                    "tokenBMint": token_b_mint,
                    "tradeSide": format!("{:?}", trade_side)
                });
                decoded_events.push(crate::DexlabDecodedEvent::Swap(crate::DexlabSwapDecoded {
                    transaction_id,
                    instruction_id,
                    signature: transaction.signature.clone(),
                    program_id: program_id.clone(),
                    trade_side,
                    pool_account,
                    token_a_mint,
                    token_b_mint,
                    payload_json,
                }));
            }
        }
        return Ok(decoded_events);
    }
}

fn classify_instruction_kind(
    parsed_json: std::option::Option<&serde_json::Value>,
    log_messages: &[std::string::String],
) -> DexlabInstructionKind {
    let parsed_instruction_name = extract_string_by_candidate_keys(
        parsed_json,
        &["instruction", "instructionName", "type", "name"],
    );
    if let Some(parsed_instruction_name) = parsed_instruction_name {
        let normalized = normalize_text(parsed_instruction_name.as_str());

        if normalized.contains("createpool") || normalized.contains("initializepool") {
            return DexlabInstructionKind::CreatePool;
        }
        if normalized == "swap" {
            return DexlabInstructionKind::Swap;
        }
    }
    if log_messages_contain_keyword(log_messages, "create_pool")
        || log_messages_contain_keyword(log_messages, "createpool")
        || log_messages_contain_keyword(log_messages, "initialize_pool")
        || log_messages_contain_keyword(log_messages, "initializepool")
    {
        return DexlabInstructionKind::CreatePool;
    }
    if log_messages_contain_keyword(log_messages, "swap") {
        return DexlabInstructionKind::Swap;
    }
    return DexlabInstructionKind::Unknown;
}

fn extract_log_messages(
    transaction_json: &serde_json::Value,
) -> std::vec::Vec<std::string::String> {
    let mut messages = std::vec::Vec::new();
    let meta_option = transaction_json.get("meta");
    let meta = match meta_option {
        Some(meta) => meta,
        None => return messages,
    };
    let logs_option = meta.get("logMessages");
    let logs = match logs_option {
        Some(logs) => logs,
        None => return messages,
    };
    let logs_array = match logs.as_array() {
        Some(logs_array) => logs_array,
        None => return messages,
    };
    for value in logs_array {
        let text_option = value.as_str();
        if let Some(text) = text_option {
            messages.push(text.to_string());
        }
    }
    return messages;
}

fn log_messages_contain_keyword(
    log_messages_contain_keyword: &[std::string::String],
    keyword: &str,
) -> bool {
    let keyword_normalized = normalize_text(keyword);
    for log_message in log_messages_contain_keyword {
        let log_normalized = normalize_text(log_message.as_str());
        if log_normalized.contains(keyword_normalized.as_str()) {
            return true;
        }
    }
    return false;
}

fn normalize_text(normalize_text: &str) -> std::string::String {
    let mut normalized = std::string::String::new();
    for character in normalize_text.chars() {
        if character.is_ascii_alphanumeric() {
            normalized.push(character.to_ascii_lowercase());
        }
    }
    return normalized;
}

fn parse_accounts_json(
    accounts_json: &str,
) -> Result<std::vec::Vec<std::string::String>, crate::Error> {
    let values_result = serde_json::from_str::<std::vec::Vec<serde_json::Value>>(accounts_json);
    let values = match values_result {
        Ok(values) => values,
        Err(error) => {
            return Err(crate::Error::Json(format!(
                "cannot parse instruction accounts_json '{}': {}",
                accounts_json, error
            )));
        },
    };
    let mut accounts = std::vec::Vec::new();
    for value in values {
        let text_option = value.as_str();
        if let Some(text) = text_option {
            accounts.push(text.to_string());
        }
    }
    return Ok(accounts);
}

fn parse_optional_parsed_json(
    parsed_json: std::option::Option<&std::string::String>,
) -> Result<std::option::Option<serde_json::Value>, crate::Error> {
    let parsed_json = match parsed_json {
        Some(parsed_json) => parsed_json,
        None => return Ok(None),
    };
    let value_result = serde_json::from_str::<serde_json::Value>(parsed_json.as_str());
    match value_result {
        Ok(value) => return Ok(Some(value)),
        Err(error) => {
            return Err(crate::Error::Json(format!(
                "cannot parse instruction parsed_json '{}': {}",
                parsed_json, error
            )));
        },
    }
}

fn extract_string_by_candidate_keys(
    value: std::option::Option<&serde_json::Value>,
    candidate_keys: &[&str],
) -> std::option::Option<std::string::String> {
    let value = match value {
        Some(value) => value,
        None => return None,
    };
    return extract_string_by_candidate_keys_inner(value, candidate_keys);
}

fn extract_string_by_candidate_keys_inner(
    value: &serde_json::Value,
    candidate_keys: &[&str],
) -> std::option::Option<std::string::String> {
    if let Some(object) = value.as_object() {
        for candidate_key in candidate_keys {
            let direct_option = object.get(*candidate_key);
            if let Some(direct) = direct_option {
                let direct_text_option = direct.as_str();
                if let Some(direct_text) = direct_text_option {
                    return Some(direct_text.to_string());
                }
            }
        }
        for nested_value in object.values() {
            let nested_result =
                extract_string_by_candidate_keys_inner(nested_value, candidate_keys);
            if nested_result.is_some() {
                return nested_result;
            }
        }
        return None;
    }
    if let Some(array) = value.as_array() {
        for nested_value in array {
            let nested_result =
                extract_string_by_candidate_keys_inner(nested_value, candidate_keys);
            if nested_result.is_some() {
                return nested_result;
            }
        }
    }
    return None;
}

fn extract_account(
    extract_account: &[std::string::String],
    index: usize,
) -> std::option::Option<std::string::String> {
    if index >= extract_account.len() {
        return None;
    }
    return Some(extract_account[index].clone());
}

fn infer_trade_side(log_messages: &[std::string::String]) -> crate::SwapTradeSide {
    if log_messages_contain_keyword(log_messages, "buy") {
        return crate::SwapTradeSide::BuyBase;
    }
    if log_messages_contain_keyword(log_messages, "sell") {
        return crate::SwapTradeSide::SellBase;
    }
    return crate::SwapTradeSide::Unknown;
}

#[cfg(test)]
mod tests {
    fn make_create_transaction() -> crate::ChainTransactionDto {
        let mut dto = crate::ChainTransactionDto::new(
            "sig-dexlab-create-1".to_string(),
            Some(893001),
            Some(1779800001),
            Some("helius_primary_http".to_string()),
            Some("0".to_string()),
            None,
            None,
            serde_json::json!({
                "slot": 893001,
                "meta": {
                    "logMessages": [
                        "Program log: Instruction: CreatePool"
                    ]
                },
                "transaction": {
                    "message": {
                        "instructions": []
                    }
                }
            })
            .to_string(),
        );
        dto.id = Some(801);
        return dto;
    }

    fn make_create_instruction() -> crate::ChainInstructionDto {
        let mut dto = crate::ChainInstructionDto::new(
            801,
            None,
            0,
            None,
            Some(crate::DEXLAB_PROGRAM_ID.to_string()),
            Some("dexlab".to_string()),
            Some(1),
            serde_json::json!([
                "DexlabPool111",
                "DexlabTokenA111",
                crate::WSOL_MINT_ID,
                "DexlabCreator111"
            ])
            .to_string(),
            None,
            None,
            Some(
                serde_json::json!({
                    "info": {
                        "instruction": "create_pool",
                        "pool": "DexlabPool111",
                        "tokenA": "DexlabTokenA111",
                        "tokenB": crate::WSOL_MINT_ID,
                        "payer": "DexlabCreator111",
                        "feeTier": "0.3%"
                    }
                })
                .to_string(),
            ),
        );
        dto.id = Some(802);
        return dto;
    }

    fn make_swap_transaction() -> crate::ChainTransactionDto {
        let mut dto = crate::ChainTransactionDto::new(
            "sig-dexlab-swap-1".to_string(),
            Some(893002),
            Some(1779800002),
            Some("helius_primary_http".to_string()),
            Some("0".to_string()),
            None,
            None,
            serde_json::json!({
                "slot": 893002,
                "meta": {
                    "logMessages": [
                        "Program log: Instruction: Swap"
                    ]
                },
                "transaction": {
                    "message": {
                        "instructions": []
                    }
                }
            })
            .to_string(),
        );
        dto.id = Some(803);
        return dto;
    }

    fn make_swap_instruction() -> crate::ChainInstructionDto {
        let mut dto = crate::ChainInstructionDto::new(
            803,
            None,
            0,
            None,
            Some(crate::DEXLAB_PROGRAM_ID.to_string()),
            Some("dexlab".to_string()),
            Some(1),
            serde_json::json!(["DexlabSwapPool111", "DexlabSwapTokenA111", crate::WSOL_MINT_ID])
                .to_string(),
            None,
            None,
            Some(
                serde_json::json!({
                    "info": {
                        "instruction": "swap",
                        "pool": "DexlabSwapPool111",
                        "tokenA": "DexlabSwapTokenA111",
                        "tokenB": crate::WSOL_MINT_ID
                    }
                })
                .to_string(),
            ),
        );
        dto.id = Some(804);
        return dto;
    }

    #[test]
    fn dexlab_create_pool_is_detected() {
        let decoder = crate::DexlabDecoder::new();
        let transaction = make_create_transaction();
        let instructions = vec![make_create_instruction()];
        let decoded_result = decoder.decode_transaction(&transaction, &instructions);
        let decoded = match decoded_result {
            Ok(decoded) => decoded,
            Err(error) => panic!("decode must succeed: {}", error),
        };
        assert_eq!(decoded.len(), 1);
        match &decoded[0] {
            crate::DexlabDecodedEvent::CreatePool(event) => {
                assert_eq!(event.transaction_id, 801);
                assert_eq!(event.instruction_id, 802);
                assert_eq!(event.pool_account, Some("DexlabPool111".to_string()));
                assert_eq!(event.token_a_mint, Some("DexlabTokenA111".to_string()));
                assert_eq!(event.token_b_mint, Some(crate::WSOL_MINT_ID.to_string()));
                assert_eq!(event.fee_tier, Some("0.3%".to_string()));
            },
            crate::DexlabDecodedEvent::Swap(_) => {
                panic!("unexpected swap event")
            },
        }
    }

    #[test]
    fn dexlab_swap_is_detected() {
        let decoder = crate::DexlabDecoder::new();
        let transaction = make_swap_transaction();
        let instructions = vec![make_swap_instruction()];
        let decoded_result = decoder.decode_transaction(&transaction, &instructions);
        let decoded = match decoded_result {
            Ok(decoded) => decoded,
            Err(error) => panic!("decode must succeed: {}", error),
        };
        assert_eq!(decoded.len(), 1);
        match &decoded[0] {
            crate::DexlabDecodedEvent::Swap(event) => {
                assert_eq!(event.transaction_id, 803);
                assert_eq!(event.instruction_id, 804);
                assert_eq!(event.pool_account, Some("DexlabSwapPool111".to_string()));
                assert_eq!(event.token_a_mint, Some("DexlabSwapTokenA111".to_string()));
                assert_eq!(event.token_b_mint, Some(crate::WSOL_MINT_ID.to_string()));
            },
            crate::DexlabDecodedEvent::CreatePool(_) => {
                panic!("unexpected create event")
            },
        }
    }
}