- Add associated function on `Result` type that returns the error

  type, as not every primary error code has an extended error code.
- Implement `Database.deinit` and `Database.query` functions.

1 files changed, 72 insertions, 46 deletions

diff --git a/src/db/sqlite.zig b/src/db/sqlite.zig
index 1e45537..8b2c42c 100644
--- a/src/db/sqlite.zig
+++ b/src/db/sqlite.zig
@@ -23,6 +23,20 @@ pub const Database = struct {
         path: []const u8,
     };
 
+    pub const Query = struct {
+        handle: *sqlite.sqlite3_stmt,
+
+        // https://sqlite.org/c3ref/finalize.html
+        pub fn deinit(self: *Query) void {
+            const result: Result = .from(sqlite.sqlite3_finalize(self.handle));
+
+            // TODO: maybe don't panic?
+            if (!result.isOk()) @panic("Last error was " ++ @errorName(result.asError()));
+
+            self.* = undefined;
+        }
+    };
+
     // Source: https://sqlite.org/c3ref/open.html
     pub fn init(kind: Kind) Error!Database {
         const name = switch (kind) {
@@ -34,82 +48,68 @@ pub const Database = struct {
 
         const result: Result = .from(sqlite.sqlite3_open(name.ptr, &handle));
 
-        switch (result.primary()) {
-            .ok => {},
-            inline else => |code| return @field(anyerror, @tagName(code)),
-        }
+        return if (result.isOk()) .{ .handle = handle.? } else result.asError(handle);
+    }
+
+    // https://sqlite.org/c3ref/close.html
+    pub fn deinit(self: *Database) void {
+        const result: Result = .from(sqlite.sqlite3_close(self.handle));
+
+        // TODO: check if we can loop over the unfinalised objects and commit them
+        if (!result.isOk()) @panic("There are still unfinalised objects");
 
-        return .{ .handle = handle.? };
+        self.* = undefined;
+    }
+
+    // https://sqlite.org/c3ref/prepare.html
+    pub fn query(self: *Database, statement: []const u8) Error!Query {
+        var handle: ?*sqlite.sqlite3_stmt = null;
+        var unused: [*c]const u8 = null;
+
+        const length: c_int = @truncate(@as(isize, @intCast(statement.len)));
+
+        const result: Result = .from(sqlite.sqlite3_prepare_v2(self.handle, statement.ptr, length, &handle, &unused));
+
+        return if (result.isOk()) .{ .handle = handle.? } else result.asError(self.handle);
     }
 };
 
 // Source: https://sqlite.org/rescode.html
-pub const Result = enum(i32) {
+const Result = enum(i32) {
     _,
 
     // zig fmt: off
-    pub const Primary = enum(u8) {
-        /// Successful result.
+    const Primary = enum(u8) {
         ok         = 0,
-        /// Generic error.
         @"error"   = 1,
-        /// Internal logic error in SQLite.
         internal   = 2,
-        /// Access permission denied.
         perm       = 3,
-        /// Callback routine requested an abort.
         abort      = 4,
-        /// The database file is locked.
         busy       = 5,
-        /// A table in the database is locked.
         locked     = 6,
-        /// A malloc() failed.
         nomem      = 7,
-        /// Attempt to write a readonly database.
         readonly   = 8,
-        /// Operation terminated by sqlite3_interrupt().
         interrupt  = 9,
-        /// Some kind of disk I/O error occurred.
         ioerr      = 10,
-        /// The database disk image is malformed.
         corrupt    = 11,
-        /// Unknown opcode in sqlite3_file_control().
         notfound   = 12,
-        /// Insertion failed because database is full.
         full       = 13,
-        /// Unable to open the database file.
         cantopen   = 14,
-        /// Database lock protocol error.
         protocol   = 15,
-        /// Internal use only.
         empty      = 16,
-        /// The database schema changed.
         schema     = 17,
-        /// String or BLOB exceeds size limit.
         toobig     = 18,
-        /// Abort due to constraint violation.
         constraint = 19,
-        /// Data type mismatch.
         mismatch   = 20,
-        /// Library used incorrectly.
         misuse     = 21,
-        /// Uses OS features not supported on host.
         nolfs      = 22,
-        /// Authorization denied.
         auth       = 23,
-        /// Not used.
         format     = 24,
-        /// 2nd parameter to sqlite3_bind out of range.
         range      = 25,
-        /// File opened that is not a database file.
         notadb     = 26,
-        /// Notifications from sqlite3_log().
         notice     = 27,
-        /// Warnings from sqlite3_log().
         warning    = 28,
-        /// sqlite3_step() has another row ready.
         row        = 100,
-        /// sqlite3_step() has finished executing.
         done       = 101,
 
         fn as(self: Primary, comptime T: type) T {
@@ -118,7 +118,7 @@ pub const Result = enum(i32) {
     };
 
     // zig fmt: off
-    pub const Extended = enum(i32) {
+    const Extended = enum(i32) {
         error_missing_collseq   = (Primary.@"error".as(i32)   | ( 1 << 8)),
         error_retry             = (Primary.@"error".as(i32)   | ( 2 << 8)),
         error_snapshot          = (Primary.@"error".as(i32)   | ( 3 << 8)),
@@ -201,21 +201,47 @@ pub const Result = enum(i32) {
         ok_load_permanently     = (Primary.ok.as(i32)         | ( 1 << 8)),
     };
 
-    pub fn from(value: anytype) Result {
+    fn from(value: anytype) Result {
         return @enumFromInt(value);
     }
 
-    pub fn primary(self: Result) Primary {
-        return @enumFromInt(0x000000FF & @intFromEnum(self));
+    fn isOk(self: Result) bool {
+        return if (self.asPrimary() == .ok) true else false;
+    }
+
+    fn asError(self: Result, handle: ?*sqlite.sqlite3) Database.Error {
+        const result: Result = .from(sqlite.sqlite3_extended_errcode(handle));
+        const primary = self.asPrimary();
+
+        if (self == result) switch (primary) {
+            inline else => |code| return @field(Database.Error, @tagName(code)),
+        };
+
+        const extended: Extended = @enumFromInt(@intFromEnum(result));
+
+        return switch (extended) {
+            inline else => |code| @field(Database.Error, @tagName(code)),
+        };
     }
 
-    pub fn extended(self: Result) Extended {
-        return @enumFromInt(@intFromEnum(self));
+    fn asPrimary(self: Result) Primary {
+        return @enumFromInt(0x000000FF & @intFromEnum(self));
     }
 };
 
 test {
-    const db: Database = try .init(.temp_in_memory);
+    var db: Database = try .init(.temp_in_memory);
+    // defer db.deinit();
+
+    const query = db.query(
+        \\ CREATE TABLE contacts (
+        \\         contact_id INTEGER PRIMARY KEY,
+        \\         first_name TEXT NOT NULL,
+        \\         last_name TEXT NOT NULL,
+        \\         email TEXT NOT NULL UNIQUE,
+        \\         phone TEXT NOT NULL UNIQUE
+        \\ );
+    );
 
-    _ = db;
+    std.debug.print("{any}\n", .{ query });
 }