// src/tables_data/handlers/post_table_data.rs
use tonic::Status;
use sqlx::{PgPool, Arguments};
use sqlx::postgres::PgArguments;
use chrono::{DateTime, Utc};
use common::proto::multieko2::tables_data::{PostTableDataRequest, PostTableDataResponse};
use crate::steel::handlers::execution::{self, ScriptOperation};
use std::collections::HashMap;

pub async fn post_table_data(
    db_pool: &PgPool,
    request: PostTableDataRequest,
) -> Result<PostTableDataResponse, Status> {
    let profile_name = request.profile_name;
    let table_name = request.table_name;
    let mut data = HashMap::new();
    
    // Process and validate all data values
    for (key, value) in request.data {
        let trimmed = value.trim().to_string();
        
        // Handle firma specially - it cannot be empty
        if key == "firma" && trimmed.is_empty() {
            return Err(Status::invalid_argument("Firma cannot be empty"));
        }
        
        // Add trimmed non-empty values to data map
        // Empty optional fields will be skipped in SQL generation
        if !trimmed.is_empty() || key == "firma" {
            data.insert(key, trimmed);
        }
    }

    // Lookup profile
    let profile = sqlx::query!(
        "SELECT id FROM profiles WHERE name = $1",
        profile_name
    )
    .fetch_optional(db_pool)
    .await
    .map_err(|e| Status::internal(format!("Profile lookup error: {}", e)))?;

    let profile_id = profile.ok_or_else(|| Status::not_found("Profile not found"))?.id;

    // Lookup table_definition
    let table_def = sqlx::query!(
        r#"SELECT id, columns, linked_table_id FROM table_definitions
        WHERE profile_id = $1 AND table_name = $2"#,
        profile_id,
        table_name
    )
    .fetch_optional(db_pool)
    .await
    .map_err(|e| Status::internal(format!("Table lookup error: {}", e)))?;

    let table_def = table_def.ok_or_else(|| Status::not_found("Table not found"))?;

    // Parse columns from JSON
    let columns_json: Vec<String> = serde_json::from_value(table_def.columns.clone())
        .map_err(|e| Status::internal(format!("Column parsing error: {}", e)))?;

    let mut columns = Vec::new();
    for col_def in columns_json {
        let parts: Vec<&str> = col_def.splitn(2, ' ').collect();
        if parts.len() != 2 {
            return Err(Status::internal("Invalid column format"));
        }
        let name = parts[0].trim_matches('"').to_string();
        let sql_type = parts[1].to_string();
        columns.push((name, sql_type));
    }

    // Check required system columns
    let mut required_columns = vec!["firma".to_string()];
    if let Some(linked_table_id) = table_def.linked_table_id {
        let linked_table = sqlx::query!(
            "SELECT table_name FROM table_definitions WHERE id = $1",
            linked_table_id
        )
        .fetch_one(db_pool)
        .await
        .map_err(|e| Status::internal(format!("Linked table error: {}", e)))?;

        let base_name = linked_table.table_name.splitn(2, '_').last().unwrap_or(&linked_table.table_name);
        required_columns.push(format!("{}_id", base_name));
    }

    // Validate required columns
    for col in &required_columns {
        if !data.contains_key(col) {
            return Err(Status::invalid_argument(format!("Missing required column: {}", col)));
        }
    }

    // Validate all data columns
    let system_columns = ["firma", "deleted"];
    let user_columns: Vec<&String> = columns.iter().map(|(name, _)| name).collect();
    for key in data.keys() {
        if !system_columns.contains(&key.as_str()) && !user_columns.contains(&key) {
            return Err(Status::invalid_argument(format!("Invalid column: {}", key)));
        }
    }


    // Validate Steel scripts
    let scripts = sqlx::query!(
        "SELECT target_column, script FROM table_scripts WHERE table_definitions_id = $1",
        table_def.id
    )
    .fetch_all(db_pool)
    .await
    .map_err(|e| Status::internal(format!("Failed to fetch scripts: {}", e)))?;

    for script_record in scripts {
        let target_column = script_record.target_column;

        // Check if target column is present in data
        if !data.contains_key(&target_column) {
            return Err(Status::invalid_argument(
                format!("Column '{}' is required due to an associated script", target_column)
            ));
        }

        // Parse the script
        let operation = execution::parse_script(&script_record.script, &target_column)
            .map_err(|e| Status::invalid_argument(e.to_string()))?;

        // Get source column from operation
        let source_column = match operation {
            ScriptOperation::SetToColumn { source } => source,
        };

        // Check source column presence
        let source_value = data.get(&source_column)
            .ok_or_else(|| Status::invalid_argument(
                format!("Source column '{}' required by script for '{}' is missing", source_column, target_column)
            ))?;

        // Get target value
        let target_value = data.get(&target_column)
            .ok_or_else(|| Status::invalid_argument(
                format!("Target column '{}' is missing in data", target_column)
            ))?;

        // Validate value match
        if target_value != source_value {
            return Err(Status::invalid_argument(
                format!("Value for '{}' must match '{}' as per script. Expected '{}', got '{}'",
                    target_column, source_column, source_value, target_value)
            ));
        }
    }

    // Prepare SQL parameters
    let mut params = PgArguments::default();
    let mut columns_list = Vec::new();
    let mut placeholders = Vec::new();
    let mut param_idx = 1;

    for (col, value) in data {
        let sql_type = if system_columns.contains(&col.as_str()) {
            match col.as_str() {
                "firma" => "TEXT",
                "deleted" => "BOOLEAN",
                _ => return Err(Status::invalid_argument("Invalid system column")),
            }
        } else {
            columns.iter()
                .find(|(name, _)| name == &col)
                .map(|(_, sql_type)| sql_type.as_str())
                .ok_or_else(|| Status::invalid_argument(format!("Column not found: {}", col)))?
        };

        // TODO This needs heavy adjustement. More stuff to be added for user to only pick
        // preprogrammed functions
        match sql_type {
            "TEXT" | "VARCHAR(15)" | "VARCHAR(255)" => {
                if let Some(max_len) = sql_type.strip_prefix("VARCHAR(")
                    .and_then(|s| s.strip_suffix(')'))
                    .and_then(|s| s.parse::<usize>().ok())
                {
                    if value.len() > max_len {
                        return Err(Status::internal(format!("Value too long for {}", col)));
                    }
                }
                params.add(value)
                    .map_err(|e| Status::invalid_argument(format!("Failed to add text parameter for {}: {}", col, e)))?;
            },
            "BOOLEAN" => {
                let val = value.parse::<bool>()
                    .map_err(|_| Status::invalid_argument(format!("Invalid boolean for {}", col)))?;
                params.add(val)
                    .map_err(|e| Status::invalid_argument(format!("Failed to add boolean parameter for {}: {}", col, e)))?;
            },
            "TIMESTAMPTZ" => {
                let dt = DateTime::parse_from_rfc3339(&value)
                    .map_err(|_| Status::invalid_argument(format!("Invalid timestamp for {}", col)))?;
                params.add(dt.with_timezone(&Utc))
                    .map_err(|e| Status::invalid_argument(format!("Failed to add timestamp parameter for {}: {}", col, e)))?;
            },
            _ => return Err(Status::invalid_argument(format!("Unsupported type {}", sql_type))),
        }

        columns_list.push(format!("\"{}\"", col));
        placeholders.push(format!("${}", param_idx));
        param_idx += 1;
    }

    // Ensure we have at least one column to insert
    if columns_list.is_empty() {
        return Err(Status::invalid_argument("No valid columns to insert"));
    }

    let sql = format!(
        "INSERT INTO \"{}\" ({}) VALUES ({}) RETURNING id",
        table_name,
        columns_list.join(", "),
        placeholders.join(", ")
    );

    let inserted_id: i64 = sqlx::query_scalar_with(&sql, params)
        .fetch_one(db_pool)
        .await
        .map_err(|e| Status::internal(format!("Insert failed: {}", e)))?;

    Ok(PostTableDataResponse {
        success: true,
        message: "Data inserted successfully".into(),
        inserted_id,
    })
}