shaperail_codegen/

rust.rs

use shaperail_core::{EndpointSpec, FieldSchema, FieldType, HttpMethod, ResourceDefinition};

pub struct GeneratedRustModule {
    pub file_name: String,
    pub contents: String,
}

pub struct GeneratedRustProject {
    pub modules: Vec<GeneratedRustModule>,
    pub mod_rs: String,
}

pub fn generate_project(resources: &[ResourceDefinition]) -> Result<GeneratedRustProject, String> {
    let mut modules = Vec::with_capacity(resources.len());
    for resource in resources {
        modules.push(GeneratedRustModule {
            file_name: format!("{}.rs", resource.resource),
            contents: generate_resource_module(resource)?,
        });
    }

    Ok(GeneratedRustProject {
        modules,
        mod_rs: generate_registry_module(resources),
    })
}

pub fn generate_resource_module(resource: &ResourceDefinition) -> Result<String, String> {
    let context = ResourceContext::new(resource)?;

    let model_fields = resource
        .schema
        .iter()
        .map(|(name, field)| format!("    pub {name}: {},", model_field_type(field)))
        .collect::<Vec<_>>()
        .join("\n");

    let list_helpers = context
        .collection_endpoints
        .iter()
        .map(|endpoint| generate_list_helper(&context, endpoint))
        .collect::<Result<Vec<_>, _>>()?
        .join("\n\n");

    let list_dispatch = if context.collection_endpoints.is_empty() {
        "        let _ = (endpoint, filters, search, sort, page);\n        Err(shaperail_core::ShaperailError::Internal(\"No collection endpoints are available for generated list queries\".to_string()))".to_string()
    } else {
        let arms = context
            .collection_endpoints
            .iter()
            .map(|endpoint| {
                format!(
                    "            {path:?} => self.{helper}(filters, search, sort, page).await,",
                    path = endpoint.spec.path(),
                    helper = endpoint.helper_name
                )
            })
            .collect::<Vec<_>>()
            .join("\n");

        format!(
            "        match endpoint.path() {{\n{arms}\n            _ => Err(shaperail_core::ShaperailError::Internal(format!(\"No generated list query for {{}}\", endpoint.path()))),\n        }}"
        )
    };

    Ok(format!(
        r###"//! Generated query module for the `{resource_name}` resource.
//! DO NOT EDIT — this file is auto-generated by `shaperail generate`.

use serde::{{Deserialize, Serialize}};
use serde_json::{{Map, Value}};
use shaperail_core::EndpointSpec;
#[allow(unused_imports)]
use shaperail_runtime::db::{{
    async_trait, parse_embedded_json, parse_filter, parse_optional_json, require_field,
    row_from_model, sort_direction_at, sort_field_at, FilterSet, PageRequest, ResourceRow,
    ResourceStore, SearchParam, SortParam,
}};

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct {record_name} {{
{model_fields}
}}

pub struct {store_name} {{
    pool: sqlx::PgPool,
}}

impl {store_name} {{
    pub fn new(pool: sqlx::PgPool) -> Self {{
        Self {{ pool }}
    }}

{list_helpers}
}}

#[async_trait]
impl ResourceStore for {store_name} {{
    fn resource_name(&self) -> &str {{
        "{resource_name}"
    }}

    async fn find_by_id(&self, id: &uuid::Uuid) -> Result<ResourceRow, shaperail_core::ShaperailError> {{
        let row = sqlx::query_as!(
            {record_name},
            r#"
            SELECT
                {select_columns}
            FROM "{table_name}"
            WHERE "{primary_key}" = $1{soft_delete_where}
            "#,
            id
        )
        .fetch_optional(&self.pool)
        .await?
        .ok_or(shaperail_core::ShaperailError::NotFound)?;

        row_from_model(&row)
    }}

    async fn find_all(
        &self,
        endpoint: &EndpointSpec,
        filters: &FilterSet,
        search: Option<&SearchParam>,
        sort: &SortParam,
        page: &PageRequest,
    ) -> Result<(Vec<ResourceRow>, Value), shaperail_core::ShaperailError> {{
{list_dispatch}
    }}

    async fn insert(&self, data: &Map<String, Value>) -> Result<ResourceRow, shaperail_core::ShaperailError> {{
{insert_body}
    }}

    async fn update_by_id(
        &self,
        id: &uuid::Uuid,
        data: &Map<String, Value>,
    ) -> Result<ResourceRow, shaperail_core::ShaperailError> {{
{update_body}
    }}

    async fn soft_delete_by_id(&self, id: &uuid::Uuid) -> Result<ResourceRow, shaperail_core::ShaperailError> {{
{soft_delete_body}
    }}

    async fn hard_delete_by_id(&self, id: &uuid::Uuid) -> Result<ResourceRow, shaperail_core::ShaperailError> {{
{hard_delete_body}
    }}
}}
"###,
        resource_name = resource.resource,
        record_name = context.record_name,
        store_name = context.store_name,
        model_fields = model_fields,
        list_helpers = list_helpers,
        select_columns = context.select_columns,
        table_name = resource.resource,
        primary_key = context.primary_key,
        soft_delete_where = context.soft_delete_where,
        list_dispatch = list_dispatch,
        insert_body = generate_insert_body(&context)?,
        update_body = generate_update_body(&context)?,
        soft_delete_body = generate_soft_delete_body(&context),
        hard_delete_body = generate_hard_delete_body(&context),
    ))
}

fn generate_registry_module(resources: &[ResourceDefinition]) -> String {
    let module_lines = resources
        .iter()
        .map(|resource| format!("pub mod {};", resource.resource))
        .collect::<Vec<_>>()
        .join("\n");

    let registry_lines = resources
        .iter()
        .map(|resource| {
            let store_name = format!("{}Store", to_pascal_case(&resource.resource));
            format!(
                "    stores.insert({name:?}.to_string(), std::sync::Arc::new({module}::{store_name}::new(pool.clone())));",
                name = resource.resource,
                module = resource.resource
            )
        })
        .collect::<Vec<_>>()
        .join("\n");

    format!(
        r#"#![allow(dead_code)]

{module_lines}

pub fn build_store_registry(pool: sqlx::PgPool) -> shaperail_runtime::db::StoreRegistry {{
    let mut stores: std::collections::HashMap<
        String,
        std::sync::Arc<dyn shaperail_runtime::db::ResourceStore>,
    > = std::collections::HashMap::new();
{registry_lines}
    std::sync::Arc::new(stores)
}}

/// Returns an empty controller map. Register custom controller functions here
/// or populate from `resources/<name>.controller.rs` files.
pub fn build_controller_map() -> shaperail_runtime::handlers::controller::ControllerMap {{
    shaperail_runtime::handlers::controller::ControllerMap::new()
}}

{controller_traits}
"#,
        controller_traits = generate_controller_traits(resources)
    )
}

/// Generate typed controller trait stubs for all resources that declare controllers.
///
/// For each resource with controller declarations, generates:
/// - An input struct for each endpoint action that has a controller
/// - A trait with the exact function signatures the controller must implement
///
/// This eliminates the #1 source of LLM errors: guessing controller function signatures.
fn generate_controller_traits(resources: &[ResourceDefinition]) -> String {
    let mut output = String::new();

    for resource in resources {
        let endpoints_with_controllers: Vec<_> = resource
            .endpoints
            .as_ref()
            .map(|endpoints| {
                endpoints
                    .iter()
                    .filter(|(_, ep)| ep.controller.is_some())
                    .collect::<Vec<_>>()
            })
            .unwrap_or_default();

        if endpoints_with_controllers.is_empty() {
            continue;
        }

        let pascal = to_pascal_case(&resource.resource);
        let mut trait_methods = Vec::new();

        for (action, ep) in &endpoints_with_controllers {
            let controller = ep.controller.as_ref().unwrap();
            let action_pascal = to_pascal_case(action);

            // Determine input fields for this endpoint
            let input_fields: Vec<_> = ep
                .input
                .as_ref()
                .map(|fields| {
                    fields
                        .iter()
                        .filter_map(|name| {
                            resource.schema.get(name).map(|field| {
                                format!("    pub {name}: {},", model_field_type(field))
                            })
                        })
                        .collect()
                })
                .unwrap_or_default();

            if !input_fields.is_empty() {
                output.push_str(&format!(
                    r#"
/// Input fields for the {resource_name} {action} endpoint.
/// Auto-generated from the resource schema — do not edit.
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
pub struct {pascal}{action_pascal}Input {{
{fields}
}}
"#,
                    resource_name = resource.resource,
                    fields = input_fields.join("\n"),
                ));
            }

            // Generate trait method for before hook
            if let Some(before) = &controller.before {
                if !before.starts_with(shaperail_core::WASM_HOOK_PREFIX) {
                    let input_type = if input_fields.is_empty() {
                        "serde_json::Value".to_string()
                    } else {
                        format!("{pascal}{action_pascal}Input")
                    };
                    trait_methods.push(format!(
                        "    /// Before-hook for the {action} endpoint. Called before the DB operation.\n    async fn {before}(ctx: &shaperail_runtime::handlers::ControllerContext, input: &{input_type}) -> Result<(), shaperail_core::ShaperailError>;"
                    ));
                }
            }

            // Generate trait method for after hook
            if let Some(after) = &controller.after {
                if !after.starts_with(shaperail_core::WASM_HOOK_PREFIX) {
                    trait_methods.push(format!(
                        "    /// After-hook for the {action} endpoint. Called after the DB operation.\n    async fn {after}(ctx: &shaperail_runtime::handlers::ControllerContext, result: &serde_json::Value) -> Result<serde_json::Value, shaperail_core::ShaperailError>;"
                    ));
                }
            }
        }

        if !trait_methods.is_empty() {
            output.push_str(&format!(
                r#"
/// Controller trait for the {resource_name} resource.
/// Implement this trait in `controllers/{resource_name}.controller.rs`.
/// The compiler will enforce correct signatures — no guessing needed.
#[shaperail_runtime::db::async_trait]
pub trait {pascal}Controller {{
{methods}
}}
"#,
                resource_name = resource.resource,
                methods = trait_methods.join("\n\n"),
            ));
        }
    }

    output
}

#[derive(Clone)]
struct CollectionEndpoint<'a> {
    spec: &'a EndpointSpec,
    helper_name: String,
}

struct ResourceContext<'a> {
    resource: &'a ResourceDefinition,
    record_name: String,
    store_name: String,
    primary_key: String,
    select_columns: String,
    soft_delete_where: String,
    collection_endpoints: Vec<CollectionEndpoint<'a>>,
}

impl<'a> ResourceContext<'a> {
    fn new(resource: &'a ResourceDefinition) -> Result<Self, String> {
        let primary_key = resource
            .schema
            .iter()
            .find(|(_, field)| field.primary)
            .map(|(name, _)| name.clone())
            .unwrap_or_else(|| "id".to_string());

        let select_columns = resource
            .schema
            .iter()
            .map(|(name, field)| select_column_sql(name, field))
            .collect::<Vec<_>>()
            .join(",\n                ");

        let collection_endpoints = resource
            .endpoints
            .as_ref()
            .map(|endpoints| {
                endpoints
                    .iter()
                    .filter(|(_, endpoint)| {
                        *endpoint.method() == HttpMethod::Get && !endpoint.path().contains(":id")
                    })
                    .map(|(name, endpoint)| CollectionEndpoint {
                        spec: endpoint,
                        helper_name: format!("find_all_{}", sanitize_identifier(name)),
                    })
                    .collect::<Vec<_>>()
            })
            .unwrap_or_default();

        Ok(Self {
            resource,
            record_name: format!("{}Record", to_pascal_case(&resource.resource)),
            store_name: format!("{}Store", to_pascal_case(&resource.resource)),
            primary_key,
            select_columns,
            soft_delete_where: if has_soft_delete(resource) {
                " AND \"deleted_at\" IS NULL".to_string()
            } else {
                String::new()
            },
            collection_endpoints,
        })
    }
}

fn generate_list_helper(
    context: &ResourceContext<'_>,
    endpoint: &CollectionEndpoint<'_>,
) -> Result<String, String> {
    let filters = endpoint.spec.filters.clone().unwrap_or_default();
    let search_fields = endpoint.spec.search.clone().unwrap_or_default();
    let sort_fields = endpoint.spec.sort.clone().unwrap_or_default();

    let filter_decls = filters
        .iter()
        .map(|field_name| {
            let field = context.resource.schema.get(field_name).ok_or_else(|| {
                format!(
                    "Unknown filter field '{field_name}' on resource '{}'",
                    context.resource.resource
                )
            })?;
            Ok(generate_filter_declaration(field_name, field))
        })
        .collect::<Result<Vec<_>, String>>()?
        .join("\n");

    let filter_args = filters
        .iter()
        .map(|field_name| {
            parameter_expression(
                field_name,
                context
                    .resource
                    .schema
                    .get(field_name)
                    .expect("filter field validated"),
            )
        })
        .collect::<Vec<_>>();

    let search_decl = if search_fields.is_empty() {
        String::new()
    } else {
        "        let search_term = search.map(|value| value.term.clone());".to_string()
    };
    let search_param = if search_fields.is_empty() {
        "_search"
    } else {
        "search"
    };

    let search_predicate = if search_fields.is_empty() {
        String::new()
    } else {
        search_expression(&search_fields)
    };

    let sort_decls = (0..sort_fields.len())
        .map(|index| {
            format!(
                "        let sort_field_{index} = sort_field_at(sort, {index});\n        let sort_direction_{index} = sort_direction_at(sort, {index});"
            )
        })
        .collect::<Vec<_>>()
        .join("\n");

    let filter_positions = filters
        .iter()
        .enumerate()
        .map(|(index, field_name)| (field_name.clone(), index + 1))
        .collect::<Vec<_>>();

    let search_position = if search_fields.is_empty() {
        None
    } else {
        Some(filter_positions.len() + 1)
    };

    let cursor_position = filter_positions.len() + usize::from(search_position.is_some()) + 1;
    let cursor_sort_positions = (0..sort_fields.len())
        .map(|index| {
            let base = cursor_position + 1 + (index * 2);
            (base, base + 1)
        })
        .collect::<Vec<_>>();
    let offset_sort_positions = (0..sort_fields.len())
        .map(|index| {
            let base =
                filter_positions.len() + usize::from(search_position.is_some()) + 1 + (index * 2);
            (base, base + 1)
        })
        .collect::<Vec<_>>();

    let filter_predicates = generate_filter_predicates(context, &filter_positions)?;
    let filter_clause = filter_predicates.join("\n");

    let cursor_order_by = generate_order_by(context, &sort_fields, &cursor_sort_positions)?;
    let offset_order_by = generate_order_by(context, &sort_fields, &offset_sort_positions)?;

    let mut cursor_args = filter_args.clone();
    if search_position.is_some() {
        cursor_args.push("search_term.as_deref()".to_string());
    }
    cursor_args.push("cursor".to_string());
    for index in 0..sort_fields.len() {
        cursor_args.push(format!("sort_field_{index}.as_deref()"));
        cursor_args.push(format!("sort_direction_{index}"));
    }
    cursor_args.push("*limit + 1".to_string());

    let mut count_args = filter_args.clone();
    if search_position.is_some() {
        count_args.push("search_term.as_deref()".to_string());
    }

    let mut row_args = count_args.clone();
    for index in 0..sort_fields.len() {
        row_args.push(format!("sort_field_{index}.as_deref()"));
        row_args.push(format!("sort_direction_{index}"));
    }
    row_args.push("*limit".to_string());
    row_args.push("*offset".to_string());

    let cursor_query = generate_cursor_query(
        context,
        &filter_clause,
        search_position.map(|position| (position, search_predicate.as_str())),
        cursor_position,
        &cursor_order_by,
        cursor_args.len(),
        &cursor_args,
    );
    let offset_query = generate_offset_query(
        context,
        &filter_clause,
        search_position.map(|position| (position, search_predicate.as_str())),
        &offset_order_by,
        row_args.len() - 1,
        row_args.len(),
        &count_args,
        &row_args,
    );

    Ok(format!(
        r###"    async fn {helper_name}(
        &self,
        filters: &FilterSet,
        {search_param}: Option<&SearchParam>,
        sort: &SortParam,
        page: &PageRequest,
    ) -> Result<(Vec<ResourceRow>, Value), shaperail_core::ShaperailError> {{
{filter_decls}
{search_decl}
{sort_decls}

        match page {{
            PageRequest::Cursor {{ after, limit }} => {{
                let cursor = match after {{
                    Some(cursor_value) => Some(uuid::Uuid::parse_str(
                        &shaperail_runtime::db::decode_cursor(cursor_value)?
                    ).map_err(|_| shaperail_core::ShaperailError::Validation(vec![shaperail_core::FieldError {{
                        field: "cursor".to_string(),
                        message: "Invalid cursor value".to_string(),
                        code: "invalid_cursor".to_string(),
                    }}]))?),
                    None => None,
                }};
{cursor_query}
            }}
            PageRequest::Offset {{ offset, limit }} => {{
{offset_query}
            }}
        }}
    }}"###,
        helper_name = endpoint.helper_name,
        search_param = search_param,
        filter_decls = indent_block(&filter_decls, 2),
        search_decl = indent_block(&search_decl, 2),
        sort_decls = indent_block(&sort_decls, 2),
        cursor_query = indent_block(&cursor_query, 4),
        offset_query = indent_block(&offset_query, 4),
    ))
}

fn generate_cursor_query(
    context: &ResourceContext<'_>,
    filter_clause: &str,
    search_position: Option<(usize, &str)>,
    cursor_position: usize,
    order_by: &str,
    limit_position: usize,
    args: &[String],
) -> String {
    format!(
        r###"                let rows = sqlx::query_as!(
                    {record_name},
                    r#"
                    SELECT
                        {select_columns}
                    FROM "{table_name}"
                    WHERE TRUE
{soft_delete_clause}
{filter_clause}{search_clause}
                        AND (${cursor_position}::uuid IS NULL OR "{primary_key}" > ${cursor_position})
                    ORDER BY
{order_by}
                    LIMIT ${limit_position}
                    "#,
                    {args}
                )
                .fetch_all(&self.pool)
                .await?;

                let has_more = rows.len() as i64 > *limit;
                let mut result_rows = rows;
                if has_more {{
                    result_rows.truncate(*limit as usize);
                }}

                let data = result_rows
                    .iter()
                    .map(row_from_model)
                    .collect::<Result<Vec<_>, _>>()?;
                let cursor = if has_more {{
                    result_rows
                        .last()
                        .map(|row| shaperail_runtime::db::encode_cursor(&row.{primary_key}.to_string()))
                }} else {{
                    None
                }};

                Ok((
                    data,
                    serde_json::json!({{
                        "cursor": cursor,
                        "has_more": has_more
                    }})
                ))"###,
        record_name = context.record_name,
        select_columns = context.select_columns,
        table_name = context.resource.resource,
        soft_delete_clause = if has_soft_delete(context.resource) {
            "                        AND \"deleted_at\" IS NULL\n"
        } else {
            ""
        },
        filter_clause = if filter_clause.is_empty() {
            String::new()
        } else {
            format!("{filter_clause}\n")
        },
        search_clause = search_position
            .map(|(position, expression)| {
                format!(
                    "\n                        AND (${position}::text IS NULL OR to_tsvector('english', {expression}) @@ plainto_tsquery('english', ${position}))"
                )
            })
            .unwrap_or_default(),
        cursor_position = cursor_position,
        primary_key = context.primary_key,
        order_by = order_by,
        limit_position = limit_position,
        args = args.join(",\n                    "),
    )
}

#[allow(clippy::too_many_arguments)]
fn generate_offset_query(
    context: &ResourceContext<'_>,
    filter_clause: &str,
    search_position: Option<(usize, &str)>,
    order_by: &str,
    limit_position: usize,
    offset_position: usize,
    count_args: &[String],
    row_args: &[String],
) -> String {
    let count_macro_args = if count_args.is_empty() {
        String::new()
    } else {
        format!(
            ",\n                    {}",
            count_args.join(",\n                    ")
        )
    };

    format!(
        r###"                let total = sqlx::query_scalar!(
                    r#"
                    SELECT COUNT(*) as "count!"
                    FROM "{table_name}"
                    WHERE TRUE
{soft_delete_clause}
{filter_clause}{search_clause}
                    "#{count_macro_args}
                )
                .fetch_one(&self.pool)
                .await?;

                let rows = sqlx::query_as!(
                    {record_name},
                    r#"
                    SELECT
                        {select_columns}
                    FROM "{table_name}"
                    WHERE TRUE
{soft_delete_clause}
{filter_clause}{search_clause}
                    ORDER BY
{order_by}
                    LIMIT ${limit_param}
                    OFFSET ${offset_param}
                    "#,
                    {row_args}
                )
                .fetch_all(&self.pool)
                .await?;

                let data = rows
                    .iter()
                    .map(row_from_model)
                    .collect::<Result<Vec<_>, _>>()?;

                Ok((
                    data,
                    serde_json::json!({{
                        "offset": offset,
                        "limit": limit,
                        "total": total
                    }})
                ))"###,
        table_name = context.resource.resource,
        soft_delete_clause = if has_soft_delete(context.resource) {
            "                        AND \"deleted_at\" IS NULL\n"
        } else {
            ""
        },
        filter_clause = if filter_clause.is_empty() {
            String::new()
        } else {
            format!("{filter_clause}\n")
        },
        search_clause = search_position
            .map(|(position, expression)| {
                format!(
                    "\n                        AND (${position}::text IS NULL OR to_tsvector('english', {expression}) @@ plainto_tsquery('english', ${position}))"
                )
            })
            .unwrap_or_default(),
        count_macro_args = count_macro_args,
        record_name = context.record_name,
        select_columns = context.select_columns,
        order_by = order_by,
        limit_param = limit_position,
        offset_param = offset_position,
        row_args = row_args.join(",\n                    "),
    )
}

fn generate_filter_predicates(
    context: &ResourceContext<'_>,
    positions: &[(String, usize)],
) -> Result<Vec<String>, String> {
    positions
        .iter()
        .map(|(field_name, position)| {
            let field = context.resource.schema.get(field_name).ok_or_else(|| {
                format!(
                    "Unknown filter field '{field_name}' on resource '{}'",
                    context.resource.resource
                )
            })?;
            Ok(format!(
                "                AND (${position}::{cast} IS NULL OR \"{field_name}\" = ${position})",
                cast = sql_cast_type(field)
            ))
        })
        .collect()
}

fn generate_order_by(
    context: &ResourceContext<'_>,
    sort_fields: &[String],
    positions: &[(usize, usize)],
) -> Result<String, String> {
    if sort_fields.is_empty() {
        return Ok(format!("\"{}\" ASC", context.primary_key));
    }

    let mut clauses = Vec::new();
    for ((field_param, direction_param), field_name) in positions.iter().zip(sort_fields) {
        for candidate in sort_fields {
            let field = context.resource.schema.get(candidate).ok_or_else(|| {
                format!(
                    "Unknown sort field '{candidate}' on resource '{}'",
                    context.resource.resource
                )
            })?;
            let sort_expr = sortable_expression(candidate, field);
            clauses.push(format!(
                "                CASE WHEN ${field_param}::text = '{candidate}' AND ${direction_param}::text = 'asc' THEN {sort_expr} END ASC"
            ));
            clauses.push(format!(
                "                CASE WHEN ${field_param}::text = '{candidate}' AND ${direction_param}::text = 'desc' THEN {sort_expr} END DESC"
            ));
        }
        let _ = field_name;
    }
    clauses.push(format!("                \"{}\" ASC", context.primary_key));
    Ok(clauses.join(",\n"))
}

fn generate_insert_body(context: &ResourceContext<'_>) -> Result<String, String> {
    let mut declarations = Vec::new();
    let mut columns = Vec::new();
    let mut values = Vec::new();
    let mut args = Vec::new();

    for (index, (field_name, field)) in context.resource.schema.iter().enumerate() {
        let variable_name = sanitize_identifier(field_name);
        declarations.push(generate_insert_declaration(
            field_name,
            field,
            &variable_name,
        )?);
        columns.push(format!("\"{field_name}\""));
        values.push(format!("${}", index + 1));
        args.push(variable_name);
    }

    Ok(format!(
        r###"{declarations}
        let row = sqlx::query_as!(
            {record_name},
            r#"
            INSERT INTO "{table_name}" ({columns})
            VALUES ({values})
            RETURNING
                {select_columns}
            "#,
            {args}
        )
        .fetch_one(&self.pool)
        .await?;

        row_from_model(&row)"###,
        declarations = declarations.join("\n"),
        record_name = context.record_name,
        table_name = context.resource.resource,
        columns = columns.join(", "),
        values = values.join(", "),
        select_columns = context.select_columns,
        args = args.join(",\n            "),
    ))
}

fn generate_update_body(context: &ResourceContext<'_>) -> Result<String, String> {
    let mut declarations = Vec::new();
    let mut set_clauses = Vec::new();
    let mut args = vec!["id".to_string()];
    let mut has_mutable_fields = Vec::new();
    let mut index = 2usize;

    for (field_name, field) in &context.resource.schema {
        if field.primary || field.generated {
            continue;
        }

        let present_name = format!("{}_present", sanitize_identifier(field_name));
        let value_name = sanitize_identifier(field_name);
        declarations.push(generate_update_declaration(
            field_name,
            field,
            &present_name,
            &value_name,
        ));
        has_mutable_fields.push(present_name.clone());
        set_clauses.push(format!(
            "\"{field_name}\" = CASE WHEN ${present_param} THEN ${value_param} ELSE \"{field_name}\" END",
            present_param = index,
            value_param = index + 1
        ));
        args.push(present_name);
        args.push(value_name);
        index += 2;
    }

    if let Some(updated_at) = context.resource.schema.get("updated_at") {
        if updated_at.generated && updated_at.field_type == FieldType::Timestamp {
            declarations.push("        let updated_at = chrono::Utc::now();".to_string());
            set_clauses.push(format!("\"updated_at\" = ${index}"));
            args.push("updated_at".to_string());
        }
    }

    let guard = if has_mutable_fields.is_empty() {
        String::new()
    } else {
        format!(
            "        if !({}) {}",
            has_mutable_fields.join(" || "),
            r#"{
            return Err(shaperail_core::ShaperailError::Validation(vec![shaperail_core::FieldError {
                field: "body".to_string(),
                message: "No valid fields to update".to_string(),
                code: "empty_update".to_string(),
            }]));
        }"#
        )
    };

    Ok(format!(
        r###"{declarations}
{guard}
        let row = sqlx::query_as!(
            {record_name},
            r#"
            UPDATE "{table_name}"
            SET {set_clauses}
            WHERE "{primary_key}" = $1{soft_delete_where}
            RETURNING
                {select_columns}
            "#,
            {args}
        )
        .fetch_optional(&self.pool)
        .await?
        .ok_or(shaperail_core::ShaperailError::NotFound)?;

        row_from_model(&row)"###,
        declarations = declarations.join("\n"),
        guard = guard,
        record_name = context.record_name,
        table_name = context.resource.resource,
        set_clauses = set_clauses.join(", "),
        primary_key = context.primary_key,
        soft_delete_where = context.soft_delete_where,
        select_columns = context.select_columns,
        args = args.join(",\n            "),
    ))
}

fn generate_soft_delete_body(context: &ResourceContext<'_>) -> String {
    if !has_soft_delete(context.resource) {
        return generate_hard_delete_body(context);
    }

    format!(
        r###"        let deleted_at = chrono::Utc::now();
        let row = sqlx::query_as!(
            {record_name},
            r#"
            UPDATE "{table_name}"
            SET "deleted_at" = $2
            WHERE "{primary_key}" = $1 AND "deleted_at" IS NULL
            RETURNING
                {select_columns}
            "#,
            id,
            deleted_at
        )
        .fetch_optional(&self.pool)
        .await?
        .ok_or(shaperail_core::ShaperailError::NotFound)?;

        row_from_model(&row)"###,
        record_name = context.record_name,
        table_name = context.resource.resource,
        primary_key = context.primary_key,
        select_columns = context.select_columns,
    )
}

fn generate_hard_delete_body(context: &ResourceContext<'_>) -> String {
    format!(
        r###"        let row = sqlx::query_as!(
            {record_name},
            r#"
            DELETE FROM "{table_name}"
            WHERE "{primary_key}" = $1
            RETURNING
                {select_columns}
            "#,
            id
        )
        .fetch_optional(&self.pool)
        .await?
        .ok_or(shaperail_core::ShaperailError::NotFound)?;

        row_from_model(&row)"###,
        record_name = context.record_name,
        table_name = context.resource.resource,
        primary_key = context.primary_key,
        select_columns = context.select_columns,
    )
}

fn generate_insert_declaration(
    field_name: &str,
    field: &FieldSchema,
    variable_name: &str,
) -> Result<String, String> {
    if field.generated {
        return Ok(format!(
            "        let {variable_name} = {};",
            generated_value_expression(field)
        ));
    }

    let parse_type = parse_type(field);
    let parsed = format!(
        "shaperail_runtime::db::parse_optional_json::<{parse_type}>(data, {field_name:?})?"
    );

    let expression = match (field_is_required(field), field.default.as_ref()) {
        (true, Some(default)) => format!(
            "match {parsed} {{ Some(value) => value, None => {} }}",
            default_expression(field_name, field, default)?
        ),
        (true, None) => format!("shaperail_runtime::db::require_field({parsed}, {field_name:?})?"),
        (false, Some(default)) if model_field_is_optional(field) => format!(
            "match {parsed} {{ Some(value) => Some(value), None => Some({}) }}",
            default_expression(field_name, field, default)?
        ),
        (false, Some(default)) => format!(
            "match {parsed} {{ Some(value) => value, None => {} }}",
            default_expression(field_name, field, default)?
        ),
        (false, None) => parsed,
    };

    Ok(format!("        let {variable_name} = {expression};"))
}

fn generate_update_declaration(
    field_name: &str,
    field: &FieldSchema,
    present_name: &str,
    value_name: &str,
) -> String {
    format!(
        "        let {present_name} = data.contains_key({field_name:?});\n        let {value_name} = shaperail_runtime::db::parse_optional_json::<{parse_type}>(data, {field_name:?})?;",
        parse_type = parse_type(field)
    )
}

fn generate_filter_declaration(field_name: &str, field: &FieldSchema) -> String {
    let parser = match field.field_type {
        FieldType::Uuid => "uuid::Uuid::parse_str(text).map_err(|_| shaperail_core::ShaperailError::Internal(\"invalid uuid filter\".to_string()))",
        FieldType::String | FieldType::Enum | FieldType::File => "Ok(text.to_string())",
        FieldType::Integer => "text.parse::<i32>().map_err(|_| shaperail_core::ShaperailError::Internal(\"invalid integer filter\".to_string()))",
        FieldType::Bigint => "text.parse::<i64>().map_err(|_| shaperail_core::ShaperailError::Internal(\"invalid bigint filter\".to_string()))",
        FieldType::Number => "text.parse::<f64>().map_err(|_| shaperail_core::ShaperailError::Internal(\"invalid number filter\".to_string()))",
        FieldType::Boolean => "text.parse::<bool>().map_err(|_| shaperail_core::ShaperailError::Internal(\"invalid boolean filter\".to_string()))",
        FieldType::Timestamp => "chrono::DateTime::parse_from_rfc3339(text).map(|value| value.with_timezone(&chrono::Utc)).map_err(|_| shaperail_core::ShaperailError::Internal(\"invalid timestamp filter\".to_string()))",
        FieldType::Date => "chrono::NaiveDate::parse_from_str(text, \"%Y-%m-%d\").map_err(|_| shaperail_core::ShaperailError::Internal(\"invalid date filter\".to_string()))",
        FieldType::Json => "serde_json::from_str::<serde_json::Value>(text).map_err(|_| shaperail_core::ShaperailError::Internal(\"invalid json filter\".to_string()))",
        FieldType::Array => "serde_json::from_str::<Vec<serde_json::Value>>(text).map_err(|_| shaperail_core::ShaperailError::Internal(\"invalid array filter\".to_string()))",
    };

    format!(
        "        let {var} = parse_filter(filters, {field_name:?}, \"invalid_filter\", |text| {parser})?;",
        var = field_parameter_name(field_name)
    )
}

fn field_parameter_name(field_name: &str) -> String {
    format!("filter_{}", sanitize_identifier(field_name))
}

fn parameter_expression(field_name: &str, field: &FieldSchema) -> String {
    let var = field_parameter_name(field_name);
    match field.field_type {
        FieldType::String | FieldType::Enum | FieldType::File => format!("{var}.as_deref()"),
        _ => var,
    }
}

fn select_column_sql(field_name: &str, field: &FieldSchema) -> String {
    let nullability = if model_field_is_optional(field) {
        "?"
    } else {
        "!"
    };
    let expression = match field.field_type {
        FieldType::Number => format!("\"{field_name}\"::DOUBLE PRECISION"),
        _ => format!("\"{field_name}\""),
    };
    format!(
        "{expression} as \"{field_name}{nullability}: {type_name}\"",
        type_name = query_type(field)
    )
}

fn sortable_expression(field_name: &str, field: &FieldSchema) -> String {
    match field.field_type {
        FieldType::Json | FieldType::Array | FieldType::Uuid => format!("\"{field_name}\"::text"),
        FieldType::Number => format!("\"{field_name}\"::DOUBLE PRECISION"),
        _ => format!("\"{field_name}\""),
    }
}

fn search_expression(fields: &[String]) -> String {
    fields
        .iter()
        .map(|field| format!("COALESCE(\"{field}\"::text, '')"))
        .collect::<Vec<_>>()
        .join(" || ' ' || ")
}

fn sql_cast_type(field: &FieldSchema) -> String {
    match field.field_type {
        FieldType::Uuid => "uuid".to_string(),
        FieldType::String | FieldType::Enum | FieldType::File => "text".to_string(),
        FieldType::Integer => "integer".to_string(),
        FieldType::Bigint => "bigint".to_string(),
        FieldType::Number => "double precision".to_string(),
        FieldType::Boolean => "boolean".to_string(),
        FieldType::Timestamp => "timestamptz".to_string(),
        FieldType::Date => "date".to_string(),
        FieldType::Json => "jsonb".to_string(),
        FieldType::Array => match field.items.as_deref() {
            Some("uuid") => "uuid[]".to_string(),
            Some("integer") => "integer[]".to_string(),
            Some("bigint") => "bigint[]".to_string(),
            Some("number") => "double precision[]".to_string(),
            Some("boolean") => "boolean[]".to_string(),
            _ => "text[]".to_string(),
        },
    }
}

fn query_type(field: &FieldSchema) -> String {
    match field.field_type {
        FieldType::Uuid => "uuid::Uuid".to_string(),
        FieldType::String | FieldType::Enum | FieldType::File => "String".to_string(),
        FieldType::Integer => "i32".to_string(),
        FieldType::Bigint => "i64".to_string(),
        FieldType::Number => "f64".to_string(),
        FieldType::Boolean => "bool".to_string(),
        FieldType::Timestamp => "chrono::DateTime<chrono::Utc>".to_string(),
        FieldType::Date => "chrono::NaiveDate".to_string(),
        FieldType::Json => "serde_json::Value".to_string(),
        FieldType::Array => match field.items.as_deref() {
            Some("uuid") => "Vec<uuid::Uuid>".to_string(),
            Some("integer") => "Vec<i32>".to_string(),
            Some("bigint") => "Vec<i64>".to_string(),
            Some("number") => "Vec<f64>".to_string(),
            Some("boolean") => "Vec<bool>".to_string(),
            Some("timestamp") => "Vec<chrono::DateTime<chrono::Utc>>".to_string(),
            Some("date") => "Vec<chrono::NaiveDate>".to_string(),
            _ => "Vec<String>".to_string(),
        },
    }
}

fn parse_type(field: &FieldSchema) -> String {
    query_type(field)
}

fn model_field_type(field: &FieldSchema) -> String {
    let base = query_type(field);
    if model_field_is_optional(field) {
        format!("Option<{base}>")
    } else {
        base
    }
}

fn model_field_is_optional(field: &FieldSchema) -> bool {
    !(field.primary || (field.required && !field.nullable))
}

fn field_is_required(field: &FieldSchema) -> bool {
    field.primary || (field.required && !field.nullable)
}

fn generated_value_expression(field: &FieldSchema) -> String {
    match field.field_type {
        FieldType::Uuid => "uuid::Uuid::new_v4()".to_string(),
        FieldType::Timestamp => {
            if model_field_is_optional(field) {
                "Some(chrono::Utc::now())".to_string()
            } else {
                "chrono::Utc::now()".to_string()
            }
        }
        FieldType::Date => {
            if model_field_is_optional(field) {
                "Some(chrono::Utc::now().date_naive())".to_string()
            } else {
                "chrono::Utc::now().date_naive()".to_string()
            }
        }
        _ => "Default::default()".to_string(),
    }
}

fn default_expression(
    field_name: &str,
    field: &FieldSchema,
    default: &serde_json::Value,
) -> Result<String, String> {
    Ok(match field.field_type {
        FieldType::Uuid => format!(
            "parse_embedded_json::<uuid::Uuid>({field_name:?}, serde_json::json!({default}))?"
        ),
        FieldType::String | FieldType::Enum | FieldType::File => {
            let value = default
                .as_str()
                .ok_or_else(|| format!("Default for '{field_name}' must be a string"))?;
            format!("{value:?}.to_string()")
        }
        FieldType::Integer => format!(
            "parse_embedded_json::<i32>({field_name:?}, serde_json::json!({default}))?"
        ),
        FieldType::Bigint => format!(
            "parse_embedded_json::<i64>({field_name:?}, serde_json::json!({default}))?"
        ),
        FieldType::Number => format!(
            "parse_embedded_json::<f64>({field_name:?}, serde_json::json!({default}))?"
        ),
        FieldType::Boolean => default
            .as_bool()
            .ok_or_else(|| format!("Default for '{field_name}' must be a boolean"))?
            .to_string(),
        FieldType::Timestamp => format!(
            "parse_embedded_json::<chrono::DateTime<chrono::Utc>>({field_name:?}, serde_json::json!({default}))?"
        ),
        FieldType::Date => format!(
            "parse_embedded_json::<chrono::NaiveDate>({field_name:?}, serde_json::json!({default}))?"
        ),
        FieldType::Json => format!("serde_json::json!({default})"),
        FieldType::Array => format!(
            "parse_embedded_json::<{}>({field_name:?}, serde_json::json!({default}))?",
            query_type(field)
        ),
    })
}

fn has_soft_delete(resource: &ResourceDefinition) -> bool {
    resource
        .endpoints
        .as_ref()
        .map(|endpoints| endpoints.values().any(|endpoint| endpoint.soft_delete))
        .unwrap_or(false)
}

fn sanitize_identifier(value: &str) -> String {
    let mut output = String::new();
    for ch in value.chars() {
        if ch.is_ascii_alphanumeric() {
            output.push(ch.to_ascii_lowercase());
        } else {
            output.push('_');
        }
    }

    if output.chars().next().is_some_and(|ch| ch.is_ascii_digit()) {
        output.insert(0, '_');
    }

    output
}

fn to_pascal_case(value: &str) -> String {
    value
        .split('_')
        .filter(|part| !part.is_empty())
        .map(|part| {
            let mut chars = part.chars();
            match chars.next() {
                Some(first) => {
                    let mut segment = String::new();
                    segment.extend(first.to_uppercase());
                    segment.push_str(chars.as_str());
                    segment
                }
                None => String::new(),
            }
        })
        .collect::<String>()
}

fn indent_block(block: &str, indent: usize) -> String {
    if block.trim().is_empty() {
        return String::new();
    }

    let prefix = "    ".repeat(indent);
    block
        .lines()
        .map(|line| {
            if line.is_empty() {
                String::new()
            } else {
                format!("{prefix}{line}")
            }
        })
        .collect::<Vec<_>>()
        .join("\n")
}

#[cfg(test)]
mod tests {
    use super::*;
    use indexmap::IndexMap;
    use shaperail_core::{
        AuthRule, EndpointSpec, FieldSchema, HttpMethod, PaginationStyle, ResourceDefinition,
    };

    fn sample_resource() -> ResourceDefinition {
        let mut schema = IndexMap::new();
        schema.insert(
            "id".to_string(),
            FieldSchema {
                field_type: FieldType::Uuid,
                primary: true,
                generated: true,
                required: false,
                unique: false,
                nullable: false,
                reference: None,
                min: None,
                max: None,
                format: None,
                values: None,
                default: None,
                sensitive: false,
                search: false,
                items: None,
            },
        );
        schema.insert(
            "email".to_string(),
            FieldSchema {
                field_type: FieldType::String,
                primary: false,
                generated: false,
                required: true,
                unique: true,
                nullable: false,
                reference: None,
                min: None,
                max: None,
                format: None,
                values: None,
                default: None,
                sensitive: false,
                search: true,
                items: None,
            },
        );
        schema.insert(
            "created_at".to_string(),
            FieldSchema {
                field_type: FieldType::Timestamp,
                primary: false,
                generated: true,
                required: false,
                unique: false,
                nullable: false,
                reference: None,
                min: None,
                max: None,
                format: None,
                values: None,
                default: None,
                sensitive: false,
                search: false,
                items: None,
            },
        );

        let mut endpoints = indexmap::IndexMap::new();
        endpoints.insert(
            "list".to_string(),
            EndpointSpec {
                method: Some(HttpMethod::Get),
                path: Some("/users".to_string()),
                auth: Some(AuthRule::Public),
                input: None,
                filters: Some(vec!["email".to_string()]),
                search: Some(vec!["email".to_string()]),
                pagination: Some(PaginationStyle::Cursor),
                sort: Some(vec!["created_at".to_string()]),
                cache: None,
                controller: None,
                events: None,
                jobs: None,
                upload: None,
                soft_delete: false,
            },
        );

        ResourceDefinition {
            resource: "users".to_string(),
            version: 1,
            db: None,
            tenant_key: None,
            schema,
            endpoints: Some(endpoints),
            relations: None,
            indexes: None,
        }
    }

    #[test]
    fn generates_query_as_store_module() {
        let resource = sample_resource();
        let code = generate_resource_module(&resource).unwrap();

        assert!(code.contains("impl ResourceStore for UsersStore"));
        assert!(code.contains("sqlx::query_as!"));
        assert!(code.contains("find_all_list"));
    }

    #[test]
    fn generates_registry_module() {
        let resource = sample_resource();
        let project = generate_project(&[resource]).unwrap();

        assert!(project.mod_rs.contains("pub mod users;"));
        assert!(project.mod_rs.contains("build_store_registry"));
    }
}