const std = @import("std");
const testing = std.testing;
const patterns = @import("patterns.zig");
const mock_codegen = @import("mock_codegen.zig");

test "mock generation - simple function" {
    var arena = std.heap.ArenaAllocator.init(testing.allocator);
    defer arena.deinit();
    const allocator = arena.allocator();

    const params = try allocator.dupe(patterns.ParamDecl, &[_]patterns.ParamDecl{
        .{ .name = "debug_mode", .type_name = "bool" },
    });

    const func = patterns.FunctionDecl{
        .name = "SDL_CreateGPUDevice",
        .return_type = "SDL_GPUDevice*",
        .params = params,
        .doc_comment = null,
    };

    const decls = try allocator.dupe(patterns.Declaration, &[_]patterns.Declaration{
        .{ .function_decl = func },
    });

    const output = try mock_codegen.MockCodeGen.generate(allocator, decls);
    
    // Should contain function declaration
    try testing.expect(std.mem.indexOf(u8, output, "SDL_CreateGPUDevice") != null);
    // Should contain parameter
    try testing.expect(std.mem.indexOf(u8, output, "bool debug_mode") != null);
    // Should void the parameter
    try testing.expect(std.mem.indexOf(u8, output, "(void)debug_mode") != null);
    // Should return NULL for pointer
    try testing.expect(std.mem.indexOf(u8, output, "return NULL") != null);
}

test "mock generation - void function" {
    var arena = std.heap.ArenaAllocator.init(testing.allocator);
    defer arena.deinit();
    const allocator = arena.allocator();

    const params = try allocator.dupe(patterns.ParamDecl, &[_]patterns.ParamDecl{
        .{ .name = "device", .type_name = "SDL_GPUDevice*" },
    });

    const func = patterns.FunctionDecl{
        .name = "SDL_DestroyGPUDevice",
        .return_type = "void",
        .params = params,
        .doc_comment = null,
    };

    const decls = try allocator.dupe(patterns.Declaration, &[_]patterns.Declaration{
        .{ .function_decl = func },
    });

    const output = try mock_codegen.MockCodeGen.generate(allocator, decls);
    
    // Should not have return statement for void
    try testing.expect(std.mem.indexOf(u8, output, "return") == null);
    // Should void the parameter
    try testing.expect(std.mem.indexOf(u8, output, "(void)device") != null);
}

test "mock generation - opaque type forward declaration" {
    var arena = std.heap.ArenaAllocator.init(testing.allocator);
    defer arena.deinit();
    const allocator = arena.allocator();

    const opaque_type = patterns.OpaqueType{
        .name = "SDL_GPUDevice",
        .doc_comment = null,
    };

    const decls = try allocator.dupe(patterns.Declaration, &[_]patterns.Declaration{
        .{ .opaque_type = opaque_type },
    });

    const output = try mock_codegen.MockCodeGen.generate(allocator, decls);
    
    // Should have typedef struct
    try testing.expect(std.mem.indexOf(u8, output, "typedef struct SDL_GPUDevice SDL_GPUDevice") != null);
}

test "mock generation - header and includes" {
    var arena = std.heap.ArenaAllocator.init(testing.allocator);
    defer arena.deinit();
    const allocator = arena.allocator();

    const decls = try allocator.dupe(patterns.Declaration, &[_]patterns.Declaration{});
    const output = try mock_codegen.MockCodeGen.generate(allocator, decls);
    
    // Should have standard headers
    try testing.expect(std.mem.indexOf(u8, output, "#include <stdint.h>") != null);
    try testing.expect(std.mem.indexOf(u8, output, "#include <stdbool.h>") != null);
    // Should have auto-generated comment
    try testing.expect(std.mem.indexOf(u8, output, "Auto-generated") != null);
}

test "mock generation - function with multiple parameters" {
    var arena = std.heap.ArenaAllocator.init(testing.allocator);
    defer arena.deinit();
    const allocator = arena.allocator();

    const params = try allocator.dupe(patterns.ParamDecl, &[_]patterns.ParamDecl{
        .{ .name = "render_pass", .type_name = "SDL_GPURenderPass*" },
        .{ .name = "viewport", .type_name = "const SDL_GPUViewport*" },
    });

    const func = patterns.FunctionDecl{
        .name = "SDL_SetGPUViewport",
        .return_type = "void",
        .params = params,
        .doc_comment = null,
    };

    const decls = try allocator.dupe(patterns.Declaration, &[_]patterns.Declaration{
        .{ .function_decl = func },
    });

    const output = try mock_codegen.MockCodeGen.generate(allocator, decls);
    
    // Should have both parameters
    try testing.expect(std.mem.indexOf(u8, output, "render_pass") != null);
    try testing.expect(std.mem.indexOf(u8, output, "viewport") != null);
    // Should void both
    try testing.expect(std.mem.indexOf(u8, output, "(void)render_pass") != null);
    try testing.expect(std.mem.indexOf(u8, output, "(void)viewport") != null);
}

test "mock generation - function returning bool" {
    var arena = std.heap.ArenaAllocator.init(testing.allocator);
    defer arena.deinit();
    const allocator = arena.allocator();

    const params = try allocator.dupe(patterns.ParamDecl, &[_]patterns.ParamDecl{
        .{ .name = "format", .type_name = "SDL_GPUShaderFormat" },
    });

    const func = patterns.FunctionDecl{
        .name = "SDL_GPUSupportsShaderFormats",
        .return_type = "bool",
        .params = params,
        .doc_comment = null,
    };

    const decls = try allocator.dupe(patterns.Declaration, &[_]patterns.Declaration{
        .{ .function_decl = func },
    });

    const output = try mock_codegen.MockCodeGen.generate(allocator, decls);
    
    // Should return false for bool
    try testing.expect(std.mem.indexOf(u8, output, "return false") != null);
}

test "mock generation - function returning int" {
    var arena = std.heap.ArenaAllocator.init(testing.allocator);
    defer arena.deinit();
    const allocator = arena.allocator();

    const params = try allocator.dupe(patterns.ParamDecl, &[_]patterns.ParamDecl{});

    const func = patterns.FunctionDecl{
        .name = "SDL_GetGPUDeviceCount",
        .return_type = "int",
        .params = params,
        .doc_comment = null,
    };

    const decls = try allocator.dupe(patterns.Declaration, &[_]patterns.Declaration{
        .{ .function_decl = func },
    });

    const output = try mock_codegen.MockCodeGen.generate(allocator, decls);
    
    // Should return 0 for int
    try testing.expect(std.mem.indexOf(u8, output, "return 0") != null);
}