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scythe_codegen/backends/
ruby_trilogy.rs

1use std::fmt::Write;
2use std::path::Path;
3
4use scythe_backend::manifest::{BackendManifest, load_manifest};
5use scythe_backend::naming::{
6    enum_type_name, enum_variant_name, fn_name, row_struct_name, to_pascal_case,
7};
8
9use scythe_core::analyzer::{AnalyzedQuery, CompositeInfo, EnumInfo};
10use scythe_core::errors::{ErrorCode, ScytheError};
11use scythe_core::parser::QueryCommand;
12
13use crate::backend_trait::{CodegenBackend, RbsGenerationContext, ResolvedColumn, ResolvedParam};
14
15const DEFAULT_MANIFEST_TOML: &str = include_str!("../../manifests/ruby-trilogy.toml");
16
17pub struct RubyTrilogyBackend {
18    manifest: BackendManifest,
19}
20
21impl RubyTrilogyBackend {
22    pub fn new(engine: &str) -> Result<Self, ScytheError> {
23        match engine {
24            "mysql" | "mariadb" => {}
25            _ => {
26                return Err(ScytheError::new(
27                    ErrorCode::InternalError,
28                    format!("ruby-trilogy only supports MySQL, got engine '{}'", engine),
29                ));
30            }
31        }
32        let manifest_path = Path::new("backends/ruby-trilogy/manifest.toml");
33        let manifest = if manifest_path.exists() {
34            load_manifest(manifest_path)
35                .map_err(|e| ScytheError::new(ErrorCode::InternalError, format!("manifest: {e}")))?
36        } else {
37            toml::from_str(DEFAULT_MANIFEST_TOML)
38                .map_err(|e| ScytheError::new(ErrorCode::InternalError, format!("manifest: {e}")))?
39        };
40        Ok(Self { manifest })
41    }
42}
43
44/// Map a neutral type to a Ruby type coercion method for trilogy.
45fn ruby_coercion(neutral_type: &str) -> &'static str {
46    match neutral_type {
47        "int16" | "int32" | "int64" => ".to_i",
48        "float32" | "float64" => ".to_f",
49        "bool" => " == 1",
50        _ => "",
51    }
52}
53
54impl CodegenBackend for RubyTrilogyBackend {
55    fn name(&self) -> &str {
56        "ruby-trilogy"
57    }
58
59    fn manifest(&self) -> &scythe_backend::manifest::BackendManifest {
60        &self.manifest
61    }
62
63    fn supported_engines(&self) -> &[&str] {
64        &["mysql"]
65    }
66
67    fn generate_rbs_file(&self, context: &RbsGenerationContext) -> Option<String> {
68        Some(super::ruby_rbs::generate_rbs_content(context, "Trilogy"))
69    }
70
71    fn file_header(&self) -> String {
72        "# frozen_string_literal: true\n\n# Auto-generated by scythe. Do not edit.\n\nmodule Queries"
73            .to_string()
74    }
75
76    fn file_footer(&self) -> String {
77        "end".to_string()
78    }
79
80    fn generate_row_struct(
81        &self,
82        query_name: &str,
83        columns: &[ResolvedColumn],
84    ) -> Result<String, ScytheError> {
85        let struct_name = row_struct_name(query_name, &self.manifest.naming);
86        let fields = columns
87            .iter()
88            .map(|c| format!(":{}", c.field_name))
89            .collect::<Vec<_>>()
90            .join(", ");
91        let mut out = String::new();
92        let _ = writeln!(out, "  {} = Data.define({})", struct_name, fields);
93        Ok(out)
94    }
95
96    fn generate_model_struct(
97        &self,
98        table_name: &str,
99        columns: &[ResolvedColumn],
100    ) -> Result<String, ScytheError> {
101        let name = to_pascal_case(table_name);
102        self.generate_row_struct(&name, columns)
103    }
104
105    fn generate_query_fn(
106        &self,
107        analyzed: &AnalyzedQuery,
108        struct_name: &str,
109        columns: &[ResolvedColumn],
110        params: &[ResolvedParam],
111    ) -> Result<String, ScytheError> {
112        let func_name = fn_name(&analyzed.name, &self.manifest.naming);
113        let sql = super::clean_sql_with_optional(
114            &analyzed.sql,
115            &analyzed.optional_params,
116            &analyzed.params,
117        );
118        let mut out = String::new();
119
120        let param_list = params
121            .iter()
122            .map(|p| p.field_name.clone())
123            .collect::<Vec<_>>()
124            .join(", ");
125        let sep = if param_list.is_empty() { "" } else { ", " };
126
127        let param_array = if params.is_empty() {
128            "[]".to_string()
129        } else {
130            format!(
131                "[{}]",
132                params
133                    .iter()
134                    .map(|p| p.field_name.clone())
135                    .collect::<Vec<_>>()
136                    .join(", ")
137            )
138        };
139
140        match &analyzed.command {
141            QueryCommand::One => {
142                let _ = writeln!(out, "  def self.{}(client{}{})", func_name, sep, param_list);
143                let _ = writeln!(out, "    stmt = client.prepare(\"{}\")", sql);
144                let _ = writeln!(
145                    out,
146                    "    results = stmt.execute({})",
147                    param_array.trim_start_matches('[').trim_end_matches(']')
148                );
149                let _ = writeln!(out, "    row = results.first");
150                let _ = writeln!(out, "    return nil if row.nil?");
151
152                let fields = columns
153                    .iter()
154                    .enumerate()
155                    .map(|(i, c)| {
156                        let coercion = ruby_coercion(&c.neutral_type);
157                        if c.nullable {
158                            format!("{}: row[{}]&.then {{ |v| v{} }}", c.field_name, i, coercion)
159                        } else {
160                            format!("{}: row[{}]{}", c.field_name, i, coercion)
161                        }
162                    })
163                    .collect::<Vec<_>>()
164                    .join(", ");
165                let _ = writeln!(out, "    {}.new({})", struct_name, fields);
166            }
167            QueryCommand::Batch => {
168                let batch_fn_name = format!("{}_batch", func_name);
169                // Batch writes its own function signature (not the outer one)
170                let _ = writeln!(out, "  def self.{}(client, items)", batch_fn_name);
171                let _ = writeln!(out, "    stmt = client.prepare(\"{}\")", sql);
172                let _ = writeln!(out, "    items.each do |item|");
173                if params.len() > 1 {
174                    let _ = writeln!(out, "      stmt.execute(*item)");
175                } else if params.len() == 1 {
176                    let _ = writeln!(out, "      stmt.execute(item)");
177                } else {
178                    let _ = writeln!(out, "      stmt.execute");
179                }
180                let _ = writeln!(out, "    end");
181                let _ = write!(out, "  end");
182                return Ok(out);
183            }
184            QueryCommand::Many => {
185                let _ = writeln!(out, "  def self.{}(client{}{})", func_name, sep, param_list);
186                let _ = writeln!(out, "    stmt = client.prepare(\"{}\")", sql);
187                let _ = writeln!(
188                    out,
189                    "    results = stmt.execute({})",
190                    param_array.trim_start_matches('[').trim_end_matches(']')
191                );
192                let _ = writeln!(out, "    results.map do |row|");
193                let fields = columns
194                    .iter()
195                    .enumerate()
196                    .map(|(i, c)| {
197                        let coercion = ruby_coercion(&c.neutral_type);
198                        if c.nullable {
199                            format!("{}: row[{}]&.then {{ |v| v{} }}", c.field_name, i, coercion)
200                        } else {
201                            format!("{}: row[{}]{}", c.field_name, i, coercion)
202                        }
203                    })
204                    .collect::<Vec<_>>()
205                    .join(", ");
206                let _ = writeln!(out, "      {}.new({})", struct_name, fields);
207                let _ = writeln!(out, "    end");
208            }
209            QueryCommand::Exec => {
210                let _ = writeln!(out, "  def self.{}(client{}{})", func_name, sep, param_list);
211                let _ = writeln!(out, "    stmt = client.prepare(\"{}\")", sql);
212                let _ = writeln!(
213                    out,
214                    "    stmt.execute({})",
215                    param_array.trim_start_matches('[').trim_end_matches(']')
216                );
217                let _ = writeln!(out, "    nil");
218            }
219            QueryCommand::ExecResult | QueryCommand::ExecRows => {
220                let _ = writeln!(out, "  def self.{}(client{}{})", func_name, sep, param_list);
221                let _ = writeln!(out, "    stmt = client.prepare(\"{}\")", sql);
222                let _ = writeln!(
223                    out,
224                    "    stmt.execute({})",
225                    param_array.trim_start_matches('[').trim_end_matches(']')
226                );
227                let _ = writeln!(out, "    client.affected_rows");
228            }
229            QueryCommand::Grouped => unreachable!("handled as Many in codegen"),
230        }
231
232        let _ = write!(out, "  end");
233        Ok(out)
234    }
235
236    fn generate_enum_def(&self, enum_info: &EnumInfo) -> Result<String, ScytheError> {
237        let type_name = enum_type_name(&enum_info.sql_name, &self.manifest.naming);
238        let mut out = String::new();
239        let _ = writeln!(out, "  module {}", type_name);
240        for value in &enum_info.values {
241            let variant = enum_variant_name(value, &self.manifest.naming);
242            let _ = writeln!(out, "    {} = \"{}\"", variant, value);
243        }
244        let all_values = enum_info
245            .values
246            .iter()
247            .map(|v| enum_variant_name(v, &self.manifest.naming))
248            .collect::<Vec<_>>()
249            .join(", ");
250        let _ = writeln!(out, "    ALL = [{}].freeze", all_values);
251        let _ = write!(out, "  end");
252        Ok(out)
253    }
254
255    fn generate_composite_def(&self, composite: &CompositeInfo) -> Result<String, ScytheError> {
256        let name = to_pascal_case(&composite.sql_name);
257        let mut out = String::new();
258        if composite.fields.is_empty() {
259            let _ = writeln!(out, "  {} = Data.define()", name);
260        } else {
261            let fields = composite
262                .fields
263                .iter()
264                .map(|f| format!(":{}", f.name))
265                .collect::<Vec<_>>()
266                .join(", ");
267            let _ = writeln!(out, "  {} = Data.define({})", name, fields);
268        }
269        Ok(out)
270    }
271}