const std = @import("std");
const link = @import("link.zig");
const Module = @import("Module.zig");
const ErrorMsg = Module.ErrorMsg;
const Allocator = std.mem.Allocator;
const zir = @import("zir.zig");
const Package = @import("Package.zig");

test "self-hosted" {
    var ctx: TestContext = undefined;
    try ctx.init();
    defer ctx.deinit();

    try @import("stage2_tests").addCases(&ctx);

    try ctx.run();
}

pub const TestContext = struct {
    zir_cmp_output_cases: std.ArrayList(ZIRCompareOutputCase),
    zir_transform_cases: std.ArrayList(ZIRTransformCase),
    zir_error_cases: std.ArrayList(ZIRErrorCase),

    pub const ZIRCompareOutputCase = struct {
        name: []const u8,
        src_list: []const []const u8,
        expected_stdout_list: []const []const u8,
    };

    pub const ZIRTransformCase = struct {
        name: []const u8,
        cross_target: std.zig.CrossTarget,
        updates: std.ArrayList(Update),

        pub const Update = struct {
            expected: Expected,
            src: [:0]const u8,
        };

        pub const Expected = union(enum) {
            zir: []const u8,
            errors: []const []const u8,
        };

        pub fn addZIR(case: *ZIRTransformCase, src: [:0]const u8, zir_text: []const u8) void {
            case.updates.append(.{
                .src = src,
                .expected = .{ .zir = zir_text },
            }) catch unreachable;
        }

        pub fn addError(case: *ZIRTransformCase, src: [:0]const u8, errors: []const []const u8) void {
            case.updates.append(.{
                .src = src,
                .expected = .{ .errors = errors },
            }) catch unreachable;
        }
    };

    pub const ZIRErrorCase = struct {
        name: []const u8,
        src: [:0]const u8,
        expected_file_errors: []const ErrorMsg,
        expected_decl_errors: []const ErrorMsg,
        expected_export_errors: []const ErrorMsg,
        cross_target: std.zig.CrossTarget,
    };

    pub fn addZIRCompareOutput(
        ctx: *TestContext,
        name: []const u8,
        src_list: []const []const u8,
        expected_stdout_list: []const []const u8,
    ) void {
        ctx.zir_cmp_output_cases.append(.{
            .name = name,
            .src_list = src_list,
            .expected_stdout_list = expected_stdout_list,
        }) catch unreachable;
    }

    pub fn addZIRTransform(
        ctx: *TestContext,
        name: []const u8,
        cross_target: std.zig.CrossTarget,
        src: [:0]const u8,
        expected_zir: []const u8,
    ) void {
        const case = ctx.zir_transform_cases.addOne() catch unreachable;
        case.* = .{
            .name = name,
            .cross_target = cross_target,
            .updates = std.ArrayList(ZIRTransformCase.Update).init(std.heap.page_allocator),
        };
        case.updates.append(.{
            .src = src,
            .expected = .{ .zir = expected_zir },
        }) catch unreachable;
    }

    pub fn addZIRError(
        ctx: *TestContext,
        name: []const u8,
        cross_target: std.zig.CrossTarget,
        src: [:0]const u8,
        expected_file_errors: []const ErrorMsg,
        expected_decl_errors: []const ErrorMsg,
        expected_export_errors: []const ErrorMsg,
    ) void {
        ctx.zir_error_cases.append(.{
            .name = name,
            .src = src,
            .expected_file_errors = expected_file_errors,
            .expected_decl_errors = expected_decl_errors,
            .expected_export_errors = expected_export_errors,
            .cross_target = cross_target,
        }) catch unreachable;
    }

    fn init(self: *TestContext) !void {
        const allocator = std.heap.page_allocator;
        self.* = .{
            .zir_cmp_output_cases = std.ArrayList(ZIRCompareOutputCase).init(allocator),
            .zir_transform_cases = std.ArrayList(ZIRTransformCase).init(allocator),
            .zir_error_cases = std.ArrayList(ZIRErrorCase).init(allocator),
        };
    }

    fn deinit(self: *TestContext) void {
        self.zir_cmp_output_cases.deinit();
        self.zir_transform_cases.deinit();
        self.zir_error_cases.deinit();
        self.* = undefined;
    }

    fn run(self: *TestContext) !void {
        var progress = std.Progress{};
        const root_node = try progress.start("zir", self.zir_cmp_output_cases.items.len +
            self.zir_transform_cases.items.len);
        defer root_node.end();

        const native_info = try std.zig.system.NativeTargetInfo.detect(std.heap.page_allocator, .{});

        for (self.zir_cmp_output_cases.items) |case| {
            std.testing.base_allocator_instance.reset();
            try self.runOneZIRCmpOutputCase(std.testing.allocator, root_node, case, native_info.target);
            try std.testing.allocator_instance.validate();
        }
        for (self.zir_transform_cases.items) |case| {
            std.testing.base_allocator_instance.reset();
            const info = try std.zig.system.NativeTargetInfo.detect(std.testing.allocator, case.cross_target);
            try self.runOneZIRTransformCase(std.testing.allocator, root_node, case, info.target);
            try std.testing.allocator_instance.validate();
        }
        for (self.zir_error_cases.items) |case| {
            std.testing.base_allocator_instance.reset();
            const info = try std.zig.system.NativeTargetInfo.detect(std.testing.allocator, case.cross_target);
            try self.runOneZIRErrorCase(std.testing.allocator, root_node, case, info.target);
            try std.testing.allocator_instance.validate();
        }
    }

    fn runOneZIRCmpOutputCase(
        self: *TestContext,
        allocator: *Allocator,
        root_node: *std.Progress.Node,
        case: ZIRCompareOutputCase,
        target: std.Target,
    ) !void {
        var tmp = std.testing.tmpDir(.{});
        defer tmp.cleanup();

        const tmp_src_path = "test-case.zir";
        const root_pkg = try Package.create(allocator, tmp.dir, ".", tmp_src_path);
        defer root_pkg.destroy();

        var prg_node = root_node.start(case.name, case.src_list.len);
        prg_node.activate();
        defer prg_node.end();

        var module = try Module.init(allocator, .{
            .target = target,
            .output_mode = .Exe,
            .optimize_mode = .Debug,
            .bin_file_dir = tmp.dir,
            .bin_file_path = "a.out",
            .root_pkg = root_pkg,
        });
        defer module.deinit();

        for (case.src_list) |source, i| {
            var src_node = prg_node.start("update", 2);
            src_node.activate();
            defer src_node.end();

            try tmp.dir.writeFile(tmp_src_path, source);

            var update_node = src_node.start("parse,analysis,codegen", null);
            update_node.activate();
            try module.makeBinFileWritable();
            try module.update();
            update_node.end();

            var exec_result = x: {
                var exec_node = src_node.start("execute", null);
                exec_node.activate();
                defer exec_node.end();

                try module.makeBinFileExecutable();
                break :x try std.ChildProcess.exec(.{
                    .allocator = allocator,
                    .argv = &[_][]const u8{"./a.out"},
                    .cwd_dir = tmp.dir,
                });
            };
            defer allocator.free(exec_result.stdout);
            defer allocator.free(exec_result.stderr);
            switch (exec_result.term) {
                .Exited => |code| {
                    if (code != 0) {
                        std.debug.warn("elf file exited with code {}\n", .{code});
                        return error.BinaryBadExitCode;
                    }
                },
                else => return error.BinaryCrashed,
            }
            const expected_stdout = case.expected_stdout_list[i];
            if (!std.mem.eql(u8, expected_stdout, exec_result.stdout)) {
                std.debug.panic(
                    "update index {}, mismatched stdout\n====Expected (len={}):====\n{}\n====Actual (len={}):====\n{}\n========\n",
                    .{ i, expected_stdout.len, expected_stdout, exec_result.stdout.len, exec_result.stdout },
                );
            }
        }
    }

    fn runOneZIRTransformCase(
        self: *TestContext,
        allocator: *Allocator,
        root_node: *std.Progress.Node,
        case: ZIRTransformCase,
        target: std.Target,
    ) !void {
        var tmp = std.testing.tmpDir(.{});
        defer tmp.cleanup();

        var update_node = root_node.start(case.name, case.updates.items.len);
        update_node.activate();
        defer update_node.end();

        const tmp_src_path = "test-case.zir";
        const root_pkg = try Package.create(allocator, tmp.dir, ".", tmp_src_path);
        defer root_pkg.destroy();

        var module = try Module.init(allocator, .{
            .target = target,
            .output_mode = .Obj,
            .optimize_mode = .Debug,
            .bin_file_dir = tmp.dir,
            .bin_file_path = "test-case.o",
            .root_pkg = root_pkg,
        });
        defer module.deinit();

        for (case.updates.items) |update| {
            var prg_node = update_node.start("", 3);
            prg_node.activate();
            defer prg_node.end();

            try tmp.dir.writeFile(tmp_src_path, update.src);

            var module_node = prg_node.start("parse/analysis/codegen", null);
            module_node.activate();
            try module.update();
            module_node.end();

            switch (update.expected) {
                .zir => |expected_zir| {
                    var emit_node = prg_node.start("emit", null);
                    emit_node.activate();
                    var new_zir_module = try zir.emit(allocator, module);
                    defer new_zir_module.deinit(allocator);
                    emit_node.end();

                    var write_node = prg_node.start("write", null);
                    write_node.activate();
                    var out_zir = std.ArrayList(u8).init(allocator);
                    defer out_zir.deinit();
                    try new_zir_module.writeToStream(allocator, out_zir.outStream());
                    write_node.end();

                    std.testing.expectEqualSlices(u8, expected_zir, out_zir.items);
                },
                .errors => |expected_errors| {
                    var all_errors = try module.getAllErrorsAlloc();
                    defer all_errors.deinit(module.allocator);
                    for (expected_errors) |expected_error| {
                        for (all_errors.list) |full_err_msg| {
                            const text = try std.fmt.allocPrint(allocator, ":{}:{}: error: {}", .{
                                full_err_msg.line + 1,
                                full_err_msg.column + 1,
                                full_err_msg.msg,
                            });
                            defer allocator.free(text);
                            if (std.mem.eql(u8, text, expected_error)) {
                                break;
                            }
                        } else {
                            std.debug.warn(
                                "{}\nExpected this error:\n================\n{}\n================\nBut found these errors:\n================\n",
                                .{ case.name, expected_error },
                            );
                            for (all_errors.list) |full_err_msg| {
                                std.debug.warn(":{}:{}: error: {}\n", .{
                                    full_err_msg.line + 1,
                                    full_err_msg.column + 1,
                                    full_err_msg.msg,
                                });
                            }
                            std.debug.warn("================\nTest failed\n", .{});
                            std.process.exit(1);
                        }
                    }
                },
            }
        }
    }

    fn runOneZIRErrorCase(
        self: *TestContext,
        allocator: *Allocator,
        root_node: *std.Progress.Node,
        case: ZIRErrorCase,
        target: std.Target,
    ) !void {
        var tmp = std.testing.tmpDir(.{});
        defer tmp.cleanup();

        var prg_node = root_node.start(case.name, 1);
        prg_node.activate();
        defer prg_node.end();

        const tmp_src_path = "test-case.zir";
        try tmp.dir.writeFile(tmp_src_path, case.src);

        const root_pkg = try Package.create(allocator, tmp.dir, ".", tmp_src_path);
        defer root_pkg.destroy();

        var module = try Module.init(allocator, .{
            .target = target,
            .output_mode = .Obj,
            .optimize_mode = .Debug,
            .bin_file_dir = tmp.dir,
            .bin_file_path = "test-case.o",
            .root_pkg = root_pkg,
        });
        defer module.deinit();

        var module_node = prg_node.start("parse/analysis/codegen", null);
        module_node.activate();
        const failed = f: {
            module.update() catch break :f true;
            break :f false;
        };
        module_node.end();
        {
            var i = module.failed_files.iterator();
            var index: usize = 0;
            while (i.next()) |pair| : (index += 1) {
                if (index == case.expected_file_errors.len) {
                    std.debug.warn("Unexpected file error: {}\n", .{pair.value});
                    return error.UnexpectedError;
                }
                const v1 = pair.value.*;
                const v2 = case.expected_file_errors[index];
                if (v1.byte_offset != v2.byte_offset) {
                    std.debug.warn("Expected error at {}, found it at {}\n", .{ v2.byte_offset, v1.byte_offset });
                    return error.ExpectedErrorElsewhere;
                }
                if (!std.mem.eql(u8, v1.msg, v2.msg)) {
                    std.debug.warn("Expected '{}', found '{}'\n", .{ v2.msg, v1.msg });
                    return error.ExpectedOtherError;
                }
            }
        }
        {
            var i = module.failed_decls.iterator();
            var index: usize = 0;
            while (i.next()) |pair| : (index += 1) {
                if (index == case.expected_decl_errors.len) {
                    std.debug.warn("Unexpected decl error: {}\n", .{pair.value});
                    return error.UnexpectedError;
                }
                const v1 = pair.value.*;
                const v2 = case.expected_decl_errors[index];
                if (v1.byte_offset != v2.byte_offset) {
                    std.debug.warn("Expected error at {}, found it at {}\n", .{ v2.byte_offset, v1.byte_offset });
                    return error.ExpectedErrorElsewhere;
                }
                if (!std.mem.eql(u8, v1.msg, v2.msg)) {
                    std.debug.warn("Expected '{}', found '{}'\n", .{ v2.msg, v1.msg });
                    return error.ExpectedOtherError;
                }
            }
        }
        {
            var i = module.failed_exports.iterator();
            var index: usize = 0;
            while (i.next()) |pair| : (index += 1) {
                if (index == case.expected_export_errors.len) {
                    std.debug.warn("Unexpected export error: {}\n", .{pair.value});
                    return error.UnexpectedError;
                }
                const v1 = pair.value.*;
                const v2 = case.expected_export_errors[index];
                if (v1.byte_offset != v2.byte_offset) {
                    std.debug.warn("Expected error at {}, found it at {}\n", .{ v2.byte_offset, v1.byte_offset });
                    return error.ExpectedErrorElsewhere;
                }
                if (!std.mem.eql(u8, v1.msg, v2.msg)) {
                    std.debug.warn("Expected '{}', found '{}'\n", .{ v2.msg, v1.msg });
                    return error.ExpectedOtherError;
                }
            }
        }
    }
};

fn debugPrintErrors(src: []const u8, errors: var) void {
    std.debug.warn("\n", .{});
    var nl = true;
    var line: usize = 1;
    for (src) |byte| {
        if (nl) {
            std.debug.warn("{: >3}| ", .{line});
            nl = false;
        }
        if (byte == '\n') {
            nl = true;
            line += 1;
        }
        std.debug.warn("{c}", .{byte});
    }
    std.debug.warn("\n", .{});
    for (errors) |err_msg| {
        const loc = std.zig.findLineColumn(src, err_msg.byte_offset);
        std.debug.warn("{}:{}: error: {}\n", .{ loc.line + 1, loc.column + 1, err_msg.msg });
    }
}