scythe_codegen/backends/
ruby_mysql2.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, ResolvedColumn, ResolvedParam};
14
15const DEFAULT_MANIFEST_TOML: &str = include_str!("../../manifests/ruby-mysql2.toml");
16
17pub struct RubyMysql2Backend {
18    manifest: BackendManifest,
19}
20
21impl RubyMysql2Backend {
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-mysql2 only supports MySQL, got engine '{}'", engine),
29                ));
30            }
31        }
32        let manifest_path = Path::new("backends/ruby-mysql2/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 mysql2.
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 RubyMysql2Backend {
55    fn name(&self) -> &str {
56        "ruby-mysql2"
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 file_header(&self) -> String {
68        "# frozen_string_literal: true\n\n# Auto-generated by scythe. Do not edit.\n\nmodule Queries"
69            .to_string()
70    }
71
72    fn file_footer(&self) -> String {
73        "end".to_string()
74    }
75
76    fn generate_row_struct(
77        &self,
78        query_name: &str,
79        columns: &[ResolvedColumn],
80    ) -> Result<String, ScytheError> {
81        let struct_name = row_struct_name(query_name, &self.manifest.naming);
82        let fields = columns
83            .iter()
84            .map(|c| format!(":{}", c.field_name))
85            .collect::<Vec<_>>()
86            .join(", ");
87        let mut out = String::new();
88        let _ = writeln!(out, "  {} = Data.define({})", struct_name, fields);
89        Ok(out)
90    }
91
92    fn generate_model_struct(
93        &self,
94        table_name: &str,
95        columns: &[ResolvedColumn],
96    ) -> Result<String, ScytheError> {
97        let name = to_pascal_case(table_name);
98        self.generate_row_struct(&name, columns)
99    }
100
101    fn generate_query_fn(
102        &self,
103        analyzed: &AnalyzedQuery,
104        struct_name: &str,
105        columns: &[ResolvedColumn],
106        params: &[ResolvedParam],
107    ) -> Result<String, ScytheError> {
108        let func_name = fn_name(&analyzed.name, &self.manifest.naming);
109        let sql = super::clean_sql(&analyzed.sql);
110        let mut out = String::new();
111
112        let param_list = params
113            .iter()
114            .map(|p| p.field_name.clone())
115            .collect::<Vec<_>>()
116            .join(", ");
117        let sep = if param_list.is_empty() { "" } else { ", " };
118
119        let _ = writeln!(out, "  def self.{}(client{}{})", func_name, sep, param_list);
120
121        let param_array = if params.is_empty() {
122            "[]".to_string()
123        } else {
124            format!(
125                "[{}]",
126                params
127                    .iter()
128                    .map(|p| p.field_name.clone())
129                    .collect::<Vec<_>>()
130                    .join(", ")
131            )
132        };
133
134        match &analyzed.command {
135            QueryCommand::One => {
136                let _ = writeln!(out, "    stmt = client.prepare(\"{}\")", sql);
137                let _ = writeln!(
138                    out,
139                    "    results = stmt.execute({})",
140                    param_array.trim_start_matches('[').trim_end_matches(']')
141                );
142                let _ = writeln!(out, "    row = results.first");
143                let _ = writeln!(out, "    return nil if row.nil?");
144
145                let fields = columns
146                    .iter()
147                    .map(|c| {
148                        let coercion = ruby_coercion(&c.neutral_type);
149                        if c.nullable {
150                            format!(
151                                "{}: row[\"{}\"]&.then {{ |v| v{} }}",
152                                c.field_name, c.name, coercion
153                            )
154                        } else {
155                            format!("{}: row[\"{}\"]{}", c.field_name, c.name, coercion)
156                        }
157                    })
158                    .collect::<Vec<_>>()
159                    .join(", ");
160                let _ = writeln!(out, "    {}.new({})", struct_name, fields);
161            }
162            QueryCommand::Many | QueryCommand::Batch => {
163                let _ = writeln!(out, "    stmt = client.prepare(\"{}\")", sql);
164                let _ = writeln!(
165                    out,
166                    "    results = stmt.execute({})",
167                    param_array.trim_start_matches('[').trim_end_matches(']')
168                );
169                let _ = writeln!(out, "    results.map do |row|");
170                let fields = columns
171                    .iter()
172                    .map(|c| {
173                        let coercion = ruby_coercion(&c.neutral_type);
174                        if c.nullable {
175                            format!(
176                                "{}: row[\"{}\"]&.then {{ |v| v{} }}",
177                                c.field_name, c.name, coercion
178                            )
179                        } else {
180                            format!("{}: row[\"{}\"]{}", c.field_name, c.name, coercion)
181                        }
182                    })
183                    .collect::<Vec<_>>()
184                    .join(", ");
185                let _ = writeln!(out, "      {}.new({})", struct_name, fields);
186                let _ = writeln!(out, "    end");
187            }
188            QueryCommand::Exec => {
189                let _ = writeln!(out, "    stmt = client.prepare(\"{}\")", sql);
190                let _ = writeln!(
191                    out,
192                    "    stmt.execute({})",
193                    param_array.trim_start_matches('[').trim_end_matches(']')
194                );
195                let _ = writeln!(out, "    nil");
196            }
197            QueryCommand::ExecResult | QueryCommand::ExecRows => {
198                let _ = writeln!(out, "    stmt = client.prepare(\"{}\")", sql);
199                let _ = writeln!(
200                    out,
201                    "    stmt.execute({})",
202                    param_array.trim_start_matches('[').trim_end_matches(']')
203                );
204                let _ = writeln!(out, "    client.affected_rows");
205            }
206        }
207
208        let _ = write!(out, "  end");
209        Ok(out)
210    }
211
212    fn generate_enum_def(&self, enum_info: &EnumInfo) -> Result<String, ScytheError> {
213        let type_name = enum_type_name(&enum_info.sql_name, &self.manifest.naming);
214        let mut out = String::new();
215        let _ = writeln!(out, "  module {}", type_name);
216        for value in &enum_info.values {
217            let variant = enum_variant_name(value, &self.manifest.naming);
218            let _ = writeln!(out, "    {} = \"{}\"", variant, value);
219        }
220        let all_values = enum_info
221            .values
222            .iter()
223            .map(|v| enum_variant_name(v, &self.manifest.naming))
224            .collect::<Vec<_>>()
225            .join(", ");
226        let _ = writeln!(out, "    ALL = [{}].freeze", all_values);
227        let _ = write!(out, "  end");
228        Ok(out)
229    }
230
231    fn generate_composite_def(&self, composite: &CompositeInfo) -> Result<String, ScytheError> {
232        let name = to_pascal_case(&composite.sql_name);
233        let mut out = String::new();
234        if composite.fields.is_empty() {
235            let _ = writeln!(out, "  {} = Data.define()", name);
236        } else {
237            let fields = composite
238                .fields
239                .iter()
240                .map(|f| format!(":{}", f.name))
241                .collect::<Vec<_>>()
242                .join(", ");
243            let _ = writeln!(out, "  {} = Data.define({})", name, fields);
244        }
245        Ok(out)
246    }
247}
scythe_codegen/backends/ruby_mysql2.rs

scythe_codegen/backends/
ruby_mysql2.rs
