good-ormning 0.5.1

use {
    good_ormning_core::{
        sqlite::{
            graph::utils::SqliteMigrateCtx,
            query::utils::{
                SqliteFieldInfo,
                SqliteTableInfo,
            },
            schema::{
                field::FieldRef,
                table::TableRef,
            },
        },
        utils::Errs,
    },
    convert_case::{
        Casing,
        Case,
    },
    quote::{
        format_ident,
        quote,
    },
    std::{
        collections::HashMap,
        env,
        fs,
        path::Path,
    },
};
pub use {
    good_ormning_core::sqlite::*,
    good_ormning_macros::{
        good_query_many_sqlite as good_query_many,
        good_query_one_sqlite as good_query_one,
        good_query_opt_sqlite as good_query_opt,
        good_query_sqlite as good_query,
    },
};

pub struct GenerateArgs {
    /// If you have multiple databases, use this to disambiguate them. You'll also need
    /// to use it in `good_module!` and `good_query!`.
    pub db_name: Option<String>,
    /// A list of database version ids and schema versions. The ids must be consecutive
    /// but can start from any number. Once a version has been applied to a production
    /// database it shouldn't be modified again (modifications should be done in a new
    /// version).
    ///
    /// These will be turned into migrations as part of the `migrate` function.
    pub versions: Vec<(usize, Version)>,
    /// A list of queries to generate type-safe functions for.
    pub queries: Vec<Query>,
}

impl Default for GenerateArgs {
    fn default() -> Self {
        Self {
            db_name: None,
            versions: vec![],
            queries: vec![],
        }
    }
}

/// Generate Rust code for migrations and queries. Also saves schema type info for
/// proc_macros to refer to.
///
/// # Returns
///
/// * Error - a list of validation or generation errors that occurred
pub fn generate(args: GenerateArgs) -> Result<(), Vec<String>> {
    let db_name = args.db_name.as_deref().unwrap_or(good_ormning_core::utils::DEFAULT_DB_NAME);
    let out_dir = env::var("OUT_DIR").map_err(|e| vec![format!("OUT_DIR not set: {:?}", e)])?;
    let out_dir = Path::new(&out_dir);
    let output = out_dir.join(good_ormning_core::utils::rs_file_name(db_name));
    let json_dir = out_dir.join("good_ormning");
    if let Err(e) = fs::create_dir_all(&json_dir) {
        return Err(vec![format!("Error creating directory {:?}: {:?}", json_dir, e)]);
    }
    let json_path = json_dir.join(good_ormning_core::utils::json_file_name(db_name));

    // Serialize versions for proc macro
    {
        let mut versions_map: HashMap<usize, Version> = if json_path.exists() {
            serde_json::from_str(&fs::read_to_string(&json_path).unwrap()).unwrap_or_default()
        } else {
            HashMap::new()
        };
        for (version_i, version) in args.versions.iter() {
            let entry = versions_map.entry(*version_i).or_insert_with(|| Version::default());
            for (k, v) in &version.tables {
                entry.tables.insert(k.clone(), v.clone());
            }
            for (k, v) in &version.custom_types {
                entry.custom_types.insert(k.clone(), v.clone());
            }
        }
        let _ = fs::write(json_path, serde_json::to_string(&versions_map).unwrap());
    }
    let mut errs = Errs::new();
    let mut migrations = vec![];
    let mut prev_version: Option<Version> = None;
    let mut prev_version_i: Option<i64> = None;
    let mut field_lookup: HashMap<TableRef, SqliteTableInfo> = HashMap::new();
    for (version_i, version) in &args.versions {
        let path = rpds::vector![format!("Migration to {}", version_i)];
        let mut migration = vec![];

        // Prep for current version
        field_lookup.clear();
        for (table_id, table) in &version.tables {
            let mut fields: HashMap<FieldRef, SqliteFieldInfo> = HashMap::new();
            for (field_id, field) in &table.fields {
                fields.insert(FieldRef {
                    table_id: table_id.clone(),
                    field_id: field_id.clone(),
                }, SqliteFieldInfo {
                    sql_name: field.id.clone(),
                    type_: field.type_.type_.clone(),
                });
            }
            field_lookup.insert(TableRef(table_id.clone()), SqliteTableInfo {
                sql_name: table.id.clone(),
                fields: fields,
            });
        }
        let version_i = *version_i as i64;
        if let Some(i) = prev_version_i {
            if version_i != i as i64 + 1 {
                errs.err(
                    &path,
                    format!(
                        "Version numbers are not consecutive ({} to {}) - was an intermediate version deleted?",
                        i,
                        version_i
                    ),
                );
            }
        }

        // Main migrations
        {
            let mut table_sql_names = HashMap::new();
            for (table_id, table) in &version.tables {
                table_sql_names.insert(table_id.clone(), table.id.clone());
            }
            let mut state = SqliteMigrateCtx::new(errs.clone(), table_sql_names, version.clone());
            let current_nodes = version.to_migrate_nodes();
            let prev_nodes = prev_version.take().map(|s| s.to_migrate_nodes());
            good_ormning_core::graphmigrate::migrate(&mut state, prev_nodes, &current_nodes);
            for statement in &state.statements {
                migration.push(quote!{
                    {
                        let query = #statement;
                        db.execute(query, ()).to_good_error_query(query)?;
                    };
                });
            }
            errs = state.errs.clone();
        }

        // Build migration
        let pascal_db_name: String = db_name.to_case(Case::Pascal);
        let enum_name = format_ident!("Db{}Versions", pascal_db_name);
        let newtype_name = format_ident!("Db{}{}", pascal_db_name, version_i as usize);
        let enum_variant = format_ident!("V{}", version_i as usize);
        migrations.push(quote!{
            if version < #version_i {
                #(#migration) * {
                    let query = "update __good_version set version = ?";
                    db.execute(query, (#version_i,)).to_good_error_query(query) ?;
                }
                if let Some(callback) = & callback {
                    callback(#enum_name::#enum_variant(#newtype_name(db))) ?;
                }
            }
        });

        // Next iter prep
        prev_version = Some(version.clone());
        prev_version_i = Some(version_i);
    }

    // Compile, output
    let last_version_i = prev_version_i.unwrap() as i64;
    let pascal_db_name: String = db_name.to_case(Case::Pascal);
    let enum_name = format_ident!("Db{}Versions", pascal_db_name);
    let mut enum_variants = vec![];
    let mut db_types = vec![];
    for (version_i, _) in &args.versions {
        let newtype_name = format_ident!("Db{}{}", pascal_db_name, version_i);
        let enum_variant = format_ident!("V{}", version_i);
        enum_variants.push(quote!(#enum_variant(#newtype_name <'a, C >)));
        db_types.push(quote!{
            pub struct #newtype_name <'a,
            C: good_ormning:: runtime:: sqlite:: SqliteConnection >(pub &'a mut C);
        });
    }
    let latest_newtype_name = format_ident!("Db{}{}", pascal_db_name, last_version_i as usize);
    let db_alias_name = format_ident!("Db{}", pascal_db_name);
    let db_others =
        good_ormning_core::sqlite::query::generate::generate_query_functions(
            &mut errs,
            field_lookup,
            args.queries,
            "",
            quote!(#latest_newtype_name <'_, C >),
        );
    let tokens = quote!{
        use good_ormning::runtime::GoodError;
        use good_ormning::runtime::ToGoodError;
        #(#db_types) * pub enum #enum_name <'a,
        C: good_ormning:: runtime:: sqlite:: SqliteConnection > {
            #(#enum_variants,) *
        }
        pub use #latest_newtype_name as #db_alias_name;
        fn init_db(db: & mut impl good_ormning:: runtime:: sqlite:: SqliteConnection) -> Result <(),
        GoodError > {
            db.load_array_module().to_good_error(|| "Error loading array extension for array values".to_string())?;
            {
                let query =
                    "create table if not exists __good_version (rid int primary key, version bigint not null, lock int not null);";
                db.execute(query, ()).to_good_error_query(query)?;
            }
            {
                let query =
                    "insert into __good_version (rid, version, lock) values (0, -1, 0) on conflict do nothing;";
                db.execute(query, ()).to_good_error_query(query)?;
            }
            Ok(())
        }
        pub fn migrate < C: good_ormning:: runtime:: sqlite:: SqliteConnection >(
            db: & mut C,
            callback: Option <&(dyn Fn(#enum_name <'_, C >) -> Result <(), GoodError >) >
        ) -> Result <(),
        GoodError > {
            init_db(db)?;
            loop {
                let query = "update __good_version set lock = 1 where rid = 0 and lock = 0 returning version";
                let version = match db.query(query, (), |r| {
                    let ver: i64 = r.get("version")?;
                    Ok(ver)
                }).to_good_error_query(query)?.pop() {
                    Some(v) => v,
                    None => {
                        std::thread::sleep(std::time::Duration::from_millis(100));
                        continue;
                    },
                };
                if version > #last_version_i {
                    return Err(
                        GoodError(
                            format!(
                                "The latest known version is {}, but the schema is at unknown version {}",
                                #last_version_i,
                                version
                            ),
                        ),
                    );
                }
                #(#migrations) * {
                    let query = "update __good_version set lock = 0";
                    db.execute(query, ()).to_good_error_query(query)?;
                }
                return Ok(());
            }
        }
        pub fn get_schema_version(
            db: & mut impl good_ormning:: runtime:: sqlite:: SqliteConnection
        ) -> Result < Option < i64 >,
        GoodError > {
            init_db(db)?;
            let query = "select version from __good_version where rid = 0";
            let mut res = db.query(query, (), |r| -> rusqlite::Result<i64> {
                let x: i64 = r.get(0usize)?;
                Ok(x)
            }).to_good_error_query(query)?;
            if let Some(v) = res.pop() {
                if v == -1 {
                    Ok(None)
                } else {
                    Ok(Some(v))
                }
            } else {
                Ok(None)
            }
        }
        #(#db_others) *
    };
    match genemichaels_lib::format_str(&tokens.to_string(), &genemichaels_lib::FormatConfig::default()) {
        Ok(src) => {
            match fs::write(&output, src.rendered.as_bytes()) {
                Ok(_) => { },
                Err(e) => errs.err(
                    &rpds::vector![],
                    format!("Failed to write generated code to {:?}: {:?}", output, e),
                ),
            };
        },
        Err(e) => {
            errs.err(&rpds::vector![], format!("Error formatting generated code: {:?}\n{}", e, tokens));
        },
    };
    errs.raise()?;
    Ok(())
}

#[cfg(test)]
mod test {
    use {
        super::{
            generate,
            GenerateArgs,
            query::expr::SerialExpr,
            schema::field::{
                field_auto,
                field_i32,
                field_str,
            },
            Version,
        },
    };

    #[test]
    fn test_add_field_serial_bad() {
        assert!(generate(GenerateArgs {
            db_name: None,
            versions: vec![
                // Versions (previous)
                (0usize, {
                    let v = Version::new();
                    v.table("bananna").field("hizat", field_str().build());
                    v.build()
                }),
                (1usize, {
                    let v = Version::new();
                    let bananna = v.table("bananna");
                    bananna.field("hizat", field_str().build());
                    bananna.field("zomzom", field_auto().migrate_fill(SerialExpr::LitAuto(0)).build(),);
                    v.build()
                }),
            ],
            ..Default::default()
        }).is_err());
    }

    #[test]
    #[should_panic]
    fn test_add_field_dup_bad() {
        generate(GenerateArgs {
            db_name: None,
            versions: vec![
                // Versions (previous)
                (0usize, {
                    let v = Version::new();
                    v.table("bananna").field("hizat", field_str().build());
                    v.build()
                }),
                (1usize, {
                    let v = Version::new();
                    let bananna = v.table("bananna");
                    bananna.field("hizat", field_str().build());
                    bananna.field("zomzom", field_i32().build());
                    v.build()
                }),
            ],
            ..Default::default()
        }).unwrap();
    }

    #[test]
    #[should_panic]
    fn test_add_table_dup_bad() {
        generate(GenerateArgs {
            db_name: None,
            versions: vec![
                // Versions (previous)
                (0usize, {
                    let v = Version::new();
                    v.table("bananna").field("hizat", field_str().build());
                    v.build()
                }),
                (1usize, {
                    let v = Version::new();
                    v.table("bananna").field("hizat", field_str().build());
                    v.table("bananna").field("hizat", field_str().build());
                    v.build()
                }),
            ],
            ..Default::default()
        }).unwrap();
    }

    #[test]
    fn test_res_count_none_bad() {
        let v = Version::new();
        let bananna = v.table("bananna");
        bananna.field("hizat", field_str().build());
        assert!(generate(GenerateArgs {
            db_name: None,
            versions: vec![(0usize, v.build())],
            ..Default::default()
        }).is_err());
    }

    #[test]
    fn test_select_nothing_bad() {
        let v = Version::new();
        v.table("bananna").field("hizat", field_str().build());
        assert!(generate(GenerateArgs {
            db_name: None,
            versions: vec![(0usize, v.build())],
            ..Default::default()
        }).is_err());
    }

    #[test]
    fn test_returning_none_bad() {
        let v = Version::new();
        let bananna = v.table("bananna");
        bananna.field("hizat", field_str().build());
        assert!(generate(GenerateArgs {
            db_name: None,
            versions: vec![(0usize, v.build())],
            ..Default::default()
        }).is_err());
    }
}