squire-sqlite3-sys 0.0.1-alpha.3

use std::{
    env,
    path::{Path, PathBuf},
};

#[cfg(all(not(feature = "bundled"), not(feature = "linked")))]
compile_error!("no SQLite library selected: feature \"bundled\" or \"linked\" must be enabled");
#[cfg(all(feature = "bundled", feature = "linked"))]
compile_error!(
    "ambiguous SQLite library selected: features \"bundled\" and \"linked\" are mutually exclusive"
);

#[cfg(all(
    not(feature = "single-thread"),
    not(feature = "multi-thread"),
    not(feature = "serialized")
))]
compile_error!(
    "no SQLite concurrency mode selected: feature \"single-thread\", \"multi-thread\", or \"serialized\" must be enabled"
);
#[cfg(any(
    all(feature = "single-thread", feature = "multi-thread"),
    all(feature = "multi-thread", feature = "serialized"),
    all(feature = "single-thread", feature = "serialized"),
))]
compile_error!(
    "ambuigous SQLite concurrency mode selected: features \"single-thread\", \"multi-thread\", and \"serialized\" are mutually exclusive"
);

#[cfg(not(feature = "bindgen"))]
compile_error!("no SQLite bindings available: feature \"bindgen\" must be enabled");

type Result<T = ()> = std::result::Result<T, Box<dyn std::error::Error>>;

fn main() -> Result {
    let dest = out_path();

    #[cfg(feature = "bundled")]
    let header_path = {
        let build = build_bundled_sqlite(&dest)?;
        build.header()
    };
    #[cfg(all(feature = "bindgen", not(feature = "bundled")))]
    let header_path = PathBuf::from("wrapper.h");

    #[cfg(feature = "bindgen")]
    generate_bindings(&header_path, &dest.join("bindings.rs"))?;

    {
        #[cfg(feature = "static")]
        let linkage = "static";
        #[cfg(not(feature = "static"))]
        let linkage = "dylib";
        println!("cargo:rustc-link-lib={linkage}=sqlite3");
    }

    Ok(())
}

fn out_path() -> PathBuf {
    env::var_os("OUT_DIR")
        .expect("cargo did not set $OUT_DIR")
        .into()
}

#[cfg(feature = "bundled")]
fn build_bundled_sqlite(dest: &Path) -> Result<sqlite::Build> {
    let location = sqlite::Location::new(dest);

    for source in location.sources() {
        println!("cargo:rerun-if-changed={}", source.display());
    }
    println!("cargo:rustc-link-search={}", location.dest().display());

    let mut config = sqlite::Config::default();

    #[cfg(feature = "single-thread")]
    config.set(sqlite::Setting::Threading(sqlite::Threading::SingleThread));
    #[cfg(feature = "multi-thread")]
    config.set(sqlite::Setting::Threading(sqlite::Threading::MultiThread));
    #[cfg(feature = "serialized")]
    config.set(sqlite::Setting::Threading(sqlite::Threading::Serialized));

    #[cfg(feature = "armor")]
    config.set(sqlite::Setting::EnableApiArmor(true));
    #[cfg(feature = "authorization")]
    config.set(sqlite::Setting::EnableAuthorization(true));
    #[cfg(feature = "auto-vacuum")]
    config.set(sqlite::Setting::DefaultAutomaticVacuum(true));
    #[cfg(feature = "blob-io")]
    config.set(sqlite::Setting::EnableBlobIo(true));
    #[cfg(feature = "column-metadata")]
    config.set(sqlite::Setting::EnableColumnMetadata(true));
    #[cfg(feature = "decltype")]
    config.set(sqlite::Setting::EnableColumnDeclaredType(true));
    #[cfg(feature = "extensions")]
    config.set(sqlite::Setting::EnableLoadExtension(true));
    #[cfg(feature = "fts3")]
    config.set(sqlite::Setting::EnableFts3(true));
    #[cfg(feature = "fts5")]
    config.set(sqlite::Setting::EnableFts5(true));
    #[cfg(feature = "geopoly")]
    config.set(sqlite::Setting::EnableGeopoly(true));
    #[cfg(feature = "json")]
    config.set(sqlite::Setting::EnableJson(true));
    #[cfg(feature = "memory-status")]
    config.set(sqlite::Setting::DefaultMemoryStatus(true));
    #[cfg(feature = "normalize-sql")]
    config.set(sqlite::Setting::EnableNormalizeSql(true));
    #[cfg(feature = "page-vtab")]
    config.set(sqlite::Setting::EnableDatabasePagesVirtualTable(true));
    #[cfg(feature = "preupdate-hook")]
    config.set(sqlite::Setting::EnablePreUpdateHook(true));
    #[cfg(feature = "progress-callback")]
    config.set(sqlite::Setting::EnableProgressCallback(true));
    #[cfg(feature = "rtree")]
    config.set(sqlite::Setting::EnableRtree(true));
    #[cfg(feature = "serialize")]
    config.set(sqlite::Setting::EnableSerialize(true));
    #[cfg(feature = "session")]
    config.set(sqlite::Setting::EnableSession(true));
    #[cfg(feature = "shared-cache")]
    config.set(sqlite::Setting::EnableSharedCache(true));
    #[cfg(feature = "snapshot")]
    config.set(sqlite::Setting::EnableSnapshot(true));
    #[cfg(feature = "soundex")]
    config.set(sqlite::Setting::EnableSoundex(true));
    #[cfg(feature = "stat-vtab")]
    config.set(sqlite::Setting::EnableDatabaseStatisticsVirtualTable(true));
    #[cfg(feature = "stat4")]
    config.set(sqlite::Setting::EnableStat4(true));
    #[cfg(feature = "trace")]
    config.set(sqlite::Setting::EnableTrace(true));
    #[cfg(feature = "vtab")]
    config.set(sqlite::Setting::EnableVirtualTables(true));
    #[cfg(feature = "wal")]
    config.set(sqlite::Setting::EnableWriteAheadLog(true));

    #[cfg(not(feature = "json"))]
    config.set(sqlite::Setting::EnableJson(false));

    let build = sqlite::build(location, config);

    Ok(build)
}

#[cfg(feature = "bindgen")]
fn generate_bindings(header: &Path, dest: &Path) -> Result {
    let config = bindgen::builder()
        .header(header.to_str().expect("non UTF-8 sqlite3.h path"))
        .default_macro_constant_type(bindgen::MacroTypeVariation::Signed)
        .generate_cstr(true)
        .blocklist_function("sqlite3_(str_)?v[msn]*(print|append)f")
        .blocklist_type("va_list")
        .blocklist_item("^__.*")
        // Block the original sqlite3_destructor_type so we can replace it
        .blocklist_type("sqlite3_destructor_type");

    let config = if cfg!(target_vendor = "apple") {
        config.blocklist_item("^MAC_OS_(X_)?VERSION_.*")
    } else {
        config
    };

    #[cfg(not(feature = "blob-io"))]
    let config = config.blocklist_function("sqlite3_blob_\\w+");
    #[cfg(not(feature = "utf-16"))]
    let config = config.blocklist_function("sqlite3_\\w+16(be|le)?(_v\\d)?");

    let bindings = config.generate()?;

    // Parse the generated bindings using syn
    let bindings_str = bindings.to_string();
    let mut syntax_tree: syn::File = syn::parse_str(&bindings_str)
        .map_err(|e| format!("Failed to parse generated bindings: {}", e))?;

    // Functions that need their destructor parameters replaced and parameter names updated
    let target_functions = [
        // bind functions - 5th parameter (index 4)
        (
            "sqlite3_bind_blob",
            4,
            vec!["pStmt", "parameter", "value", "len", "destructor"],
        ),
        (
            "sqlite3_bind_blob64",
            4,
            vec!["pStmt", "parameter", "value", "len", "destructor"],
        ),
        (
            "sqlite3_bind_text",
            4,
            vec!["pStmt", "parameter", "value", "len", "destructor"],
        ),
        (
            "sqlite3_bind_text16",
            4,
            vec!["pStmt", "parameter", "value", "len", "destructor"],
        ),
        (
            "sqlite3_bind_text64",
            4,
            vec![
                "pStmt",
                "parameter",
                "value",
                "len",
                "destructor",
                "encoding",
            ],
        ),
        (
            "sqlite3_bind_pointer",
            4,
            vec!["pStmt", "parameter", "value", "type_name", "destructor"],
        ),
        // result functions - 4th parameter (index 3)
        (
            "sqlite3_result_blob",
            3,
            vec!["context", "value", "len", "destructor"],
        ),
        (
            "sqlite3_result_blob64",
            3,
            vec!["context", "value", "len", "destructor"],
        ),
        (
            "sqlite3_result_text",
            3,
            vec!["context", "value", "len", "destructor"],
        ),
        (
            "sqlite3_result_text64",
            3,
            vec!["context", "value", "len", "destructor", "encoding"],
        ),
        (
            "sqlite3_result_text16",
            3,
            vec!["context", "value", "len", "destructor"],
        ),
        (
            "sqlite3_result_text16le",
            3,
            vec!["context", "value", "len", "destructor"],
        ),
        (
            "sqlite3_result_text16be",
            3,
            vec!["context", "value", "len", "destructor"],
        ),
        (
            "sqlite3_result_pointer",
            3,
            vec!["context", "value", "type_name", "destructor"],
        ),
    ];

    // Transform the AST to replace destructor parameters
    for item in &mut syntax_tree.items {
        if let syn::Item::ForeignMod(foreign_mod) = item {
            for foreign_item in &mut foreign_mod.items {
                if let syn::ForeignItem::Fn(func) = foreign_item {
                    let func_name = func.sig.ident.to_string();

                    // Check if this function needs parameter substitution and renaming
                    if let Some((_, param_index, param_names)) = target_functions
                        .iter()
                        .find(|(name, _, _)| func_name == *name)
                    {
                        // Replace parameter names and the destructor type
                        for (i, param) in func.sig.inputs.iter_mut().enumerate() {
                            if let syn::FnArg::Typed(pat_type) = param {
                                // Update parameter name if we have one
                                if let Some(param_name) = param_names.get(i) {
                                    let ident =
                                        syn::Ident::new(param_name, proc_macro2::Span::call_site());
                                    pat_type.pat = Box::new(syn::parse_quote! { #ident });
                                }

                                // Replace the destructor parameter type
                                if i == *param_index {
                                    pat_type.ty =
                                        Box::new(syn::parse_quote! { sqlite3_destructor_type });
                                }
                            }
                        }
                    }
                }
            }
        }
    }

    // Convert the modified AST back to a string using prettyplease for proper formatting
    let mut modified_bindings = prettyplease::unparse(&syntax_tree);

    // Add our custom union type definition at the end
    modified_bindings.push_str(
        r#"
/// A destructor / memory `free` function for a value passed to SQLite as a
/// [bound parameter][bind] or a [function result][].
///
/// A destructor can either be a `func`tion, or one of the [special values][]
/// `SQLITE_STATIC` (`0`) or `SQLITE_TRANSIENT` (`-1`).
///
/// [bind]: https://sqlite.org/c3ref/bind_blob.html
/// [function result]: https://sqlite.org/c3ref/result_blob.html
/// [special values]: https://sqlite.org/c3ref/c_static.html
#[derive(Copy, Clone)]
#[repr(C)]
pub union sqlite3_destructor_type {
    pub func: unsafe extern "C" fn(context: *mut ::std::os::raw::c_void),
    pub sentinel: isize,
}

// Safety: The union only contains POD types
unsafe impl Send for sqlite3_destructor_type {}
unsafe impl Sync for sqlite3_destructor_type {}

impl sqlite3_destructor_type {
    /// Provide a custom [destructor](sqlite3_destructor_type) to SQLite.
    pub const fn new(func: unsafe extern "C" fn(*mut ::std::os::raw::c_void)) -> Self {
        sqlite3_destructor_type { func }
    }

    /// Construct `SQLITE_STATIC` or `SQLITE_TRANSIENT`.
    pub(crate) const fn from_sentinel(sentinel: isize) -> Self {
        sqlite3_destructor_type { sentinel }
    }
}

impl ::core::fmt::Debug for sqlite3_destructor_type {
    fn fmt(&self, f: &mut ::core::fmt::Formatter<'_>) -> ::core::fmt::Result {
        // Safety: Both fields have the same size, so reading sentinel is always valid
        let sentinel = unsafe { self.sentinel };
        match sentinel {
            0 => write!(f, "sqlite3_destructor_type::SQLITE_STATIC"),
            -1 => write!(f, "sqlite3_destructor_type::SQLITE_TRANSIENT"),
            _ => write!(f, "sqlite3_destructor_type::func({:p})", sentinel as *const ()),
        }
    }
}
"#,
    );

    std::fs::write(dest, modified_bindings)?;

    Ok(())
}