package main

import compiler_core "./compiler"
import "./compiler/ast"
import "./compiler/backend"
import "./compiler/checker"
import "./compiler/hir"
import "./compiler/ir"
import "./compiler/lexer"
import "./compiler/llvm"
import "./compiler/lower"
import "./compiler/parser"
import "./compiler/source"
import "./compiler/token"
import "./compiler/types"
import "core:os"
import "core:os/os2"
import "core:strings"
import "core:testing"

@(test)
lexer_preserves_newlines_and_skips_comments :: proc(t: ^testing.T) {
	source_file := source.Source{path="test.bro", text="# comment\nmain :: func() void {}\n"}
	diagnostics := source.init_diagnostics(&source_file)
	defer source.destroy_diagnostics(&diagnostics)
	stream := lexer.lex(&source_file, &diagnostics)
	defer delete(stream.items)

	testing.expect_value(t, len(diagnostics.items), 0)
	testing.expect_value(t, stream.items[0].kind, token.Kind.Newline)
	testing.expect_value(t, stream.items[1].kind, token.Kind.Identifier)
}

@(test)
parser_accepts_grouped_params_and_multiline_statements :: proc(t: ^testing.T) {
	text := `sum :: func(a,
	b int) int {
	return (a
		+ b)
}
main :: func() void {}
`
	source_file := source.Source{path="test.bro", text=text}
	diagnostics := source.init_diagnostics(&source_file)
	defer source.destroy_diagnostics(&diagnostics)
	stream := lexer.lex(&source_file, &diagnostics)
	defer delete(stream.items)
	module := parser.parse(&stream, &diagnostics)
	defer ast.destroy_module(&module)

	testing.expect_value(t, len(diagnostics.items), 0)
	testing.expect_value(t, len(module.functions), 2)
	testing.expect_value(t, len(module.functions[0].params), 2)
}

@(test)
pipeline_emits_specialized_calling_conventions_and_checked_add :: proc(t: ^testing.T) {
	text := `sum_c :: c func(a, b int) int {
	return a + b
}
sum_bro :: func(a, b int) int {
	return a + b
}
main :: func() void {
	_ = sum_c(1, 2)
	_ = sum_bro(1, 2)
}
`
	source_file := source.Source{path="test.bro", text=text}
	diagnostics := source.init_diagnostics(&source_file)
	defer source.destroy_diagnostics(&diagnostics)
	stream := lexer.lex(&source_file, &diagnostics)
	defer delete(stream.items)
	ast_module := parser.parse(&stream, &diagnostics)
	defer ast.destroy_module(&ast_module)
	hir_module := checker.check(&ast_module, &diagnostics)
	defer hir.destroy_module(&hir_module)
	ir_module := lower.lower(&hir_module)
	defer ir.destroy_module(&ir_module)
	llvm_text := llvm.emit(&ir_module, &diagnostics)
	defer delete(llvm_text)
	second_llvm_text := llvm.emit(&ir_module, &diagnostics)
	defer delete(second_llvm_text)

	testing.expect_value(t, len(diagnostics.items), 0)
	testing.expect_value(t, llvm_text, second_llvm_text)
	testing.expect(t, strings.contains(llvm_text, "define i8 @sum_c__i8__i8"))
	testing.expect(t, strings.contains(llvm_text, "define internal fastcc i8 @bro__sum_bro__i8__i8"))
	testing.expect(t, strings.contains(llvm_text, "@llvm.sadd.with.overflow.i8"))
}

@(test)
literal_addition_trees_fold_with_contextual_types :: proc(t: ^testing.T) {
	text := `return_i16 :: func() i16 {
	return 1 + 2
}
take_i16 :: func(value i16) i16 {
	return value
}
take_int :: func(value int) int {
	return value
}
main :: func() void {
	local i16 :: 1 + 2
	_ = 100 + (20 + 8)
	_ = return_i16()
	_ = take_i16(1 + 2)
	_ = take_int(127 + 1)
}
`
	source_file := source.Source{path="test.bro", text=text}
	diagnostics := source.init_diagnostics(&source_file)
	defer source.destroy_diagnostics(&diagnostics)
	stream := lexer.lex(&source_file, &diagnostics)
	defer delete(stream.items)
	ast_module := parser.parse(&stream, &diagnostics)
	defer ast.destroy_module(&ast_module)
	hir_module := checker.check(&ast_module, &diagnostics)
	defer hir.destroy_module(&hir_module)
	ir_module := lower.lower(&hir_module)
	defer ir.destroy_module(&ir_module)
	llvm_text := llvm.emit(&ir_module, &diagnostics)
	defer delete(llvm_text)

	testing.expect_value(t, len(diagnostics.items), 0)
	testing.expect(t, strings.contains(llvm_text, "@bro__take_int__i16"))
	for function in ir_module.functions {
		for instruction in function.instructions {
			testing.expect(t, instruction.op != ir.Opcode.Add_Checked)
		}
	}

	for function in hir_module.functions {
		for statement_id in function.body {
			statement := hir_module.statements[statement_id]
			if statement.expr < 0 {
				continue
			}
			expr := hir_module.exprs[statement.expr]
			if expr.kind == .Integer {
				testing.expect(t, types.equal(expr.type, types.I16))
			}
			if expr.kind == .Call && function.name == "main" && len(expr.args) > 0 {
				arg := hir_module.exprs[expr.args[0]]
				testing.expect_value(t, arg.kind, hir.Expr_Kind.Integer)
				testing.expect(t, types.equal(arg.type, types.I16))
			}
		}
	}
}

@(test)
runtime_arithmetic_does_not_inherit_result_context :: proc(t: ^testing.T) {
	text := `widen_after_add :: func(value i8) i16 {
	return value + 1
}
main :: func() void {
	_ = widen_after_add(1)
}
`
	source_file := source.Source{path="test.bro", text=text}
	diagnostics := source.init_diagnostics(&source_file)
	defer source.destroy_diagnostics(&diagnostics)
	stream := lexer.lex(&source_file, &diagnostics)
	defer delete(stream.items)
	ast_module := parser.parse(&stream, &diagnostics)
	defer ast.destroy_module(&ast_module)
	hir_module := checker.check(&ast_module, &diagnostics)
	defer hir.destroy_module(&hir_module)

	testing.expect_value(t, len(diagnostics.items), 0)
	found := false
	for function in hir_module.functions {
		if function.name != "widen_after_add" {
			continue
		}
		found = true
		statement := hir_module.statements[function.body[0]]
		widen := hir_module.exprs[statement.expr]
		add := hir_module.exprs[widen.left]
		testing.expect_value(t, widen.kind, hir.Expr_Kind.Widen)
		testing.expect(t, types.equal(widen.type, types.I16))
		testing.expect_value(t, add.kind, hir.Expr_Kind.Add)
		testing.expect(t, types.equal(add.type, types.I8))
	}
	testing.expect(t, found)
}

@(test)
parser_recovers_after_invalid_tokens :: proc(t: ^testing.T) {
	text := `broken @ declaration
main :: func() void {}
`
	source_file := source.Source{path="test.bro", text=text}
	diagnostics := source.init_diagnostics(&source_file)
	defer source.destroy_diagnostics(&diagnostics)
	stream := lexer.lex(&source_file, &diagnostics)
	defer delete(stream.items)
	module := parser.parse(&stream, &diagnostics)
	defer ast.destroy_module(&module)

	testing.expect(t, len(diagnostics.items) > 0)
	testing.expect_value(t, len(module.functions), 1)
	testing.expect_value(t, module.functions[0].name, "main")
}

@(test)
return_sink_and_unconsumed_values_have_distinct_hir :: proc(t: ^testing.T) {
	text := `give :: func() i8 {
	return 1
}
done :: func() void {
	return _
}
main :: func() void {
	done()
	_ = give()
	give()
}
`
	source_file := source.Source{path="test.bro", text=text}
	diagnostics := source.init_diagnostics(&source_file)
	defer source.destroy_diagnostics(&diagnostics)
	stream := lexer.lex(&source_file, &diagnostics)
	defer delete(stream.items)
	ast_module := parser.parse(&stream, &diagnostics)
	defer ast.destroy_module(&ast_module)
	hir_module := checker.check(&ast_module, &diagnostics)
	defer hir.destroy_module(&hir_module)

	done_id, main_id := -1, -1
	for function, id in hir_module.functions {
		if function.name == "done" {
			done_id = id
		} else if function.name == "main" {
			main_id = id
		}
	}
	testing.expect(t, done_id >= 0)
	testing.expect(t, main_id >= 0)
	testing.expect_value(t, hir_module.statements[hir_module.functions[done_id].body[0]].kind, hir.Stmt_Kind.Return)
	testing.expect_value(t, hir_module.statements[hir_module.functions[done_id].body[0]].expr, -1)
	main := hir_module.functions[main_id]
	testing.expect_value(t, hir_module.statements[main.body[0]].kind, hir.Stmt_Kind.Expression)
	testing.expect_value(t, hir_module.statements[main.body[1]].kind, hir.Stmt_Kind.Sink)
	testing.expect_value(t, hir_module.statements[main.body[2]].kind, hir.Stmt_Kind.Trap)
}

@(test)
recursive_specialization_reaches_a_fixed_point :: proc(t: ^testing.T) {
	text := `a :: func(value int) i32 {
	return b(value)
}
b :: func(value int) i32 {
	return a(value)
}
main :: func() void {
	_ = a(1)
}
`
	source_file := source.Source{path="test.bro", text=text}
	diagnostics := source.init_diagnostics(&source_file)
	defer source.destroy_diagnostics(&diagnostics)
	stream := lexer.lex(&source_file, &diagnostics)
	defer delete(stream.items)
	ast_module := parser.parse(&stream, &diagnostics)
	defer ast.destroy_module(&ast_module)
	hir_module := checker.check(&ast_module, &diagnostics)
	defer hir.destroy_module(&hir_module)

	testing.expect_value(t, len(diagnostics.items), 0)
	testing.expect_value(t, len(hir_module.functions), 3)
}

run_executable :: proc(path: string) -> os2.Process_State {
	state, stdout, stderr, _ := os2.process_exec(
		os2.Process_Desc{command=[]string{path}},
		context.allocator,
	)
	delete(stdout)
	delete(stderr)
	return state
}

@(test)
valid_program_compiles_and_runs :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-valid"
	defer _ = os.remove(output)
	status := compiler_core.compile_file("examples/prototype.bro", output)
	testing.expect_value(t, status, 0)
	state := run_executable(output)
	testing.expect_value(t, state.exit_code, 0)
}

@(test)
folded_constant_addition_compiles_and_runs :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-constant-fold"
	defer _ = os.remove(output)
	status := compiler_core.compile_file("examples/constant_fold.bro", output)
	testing.expect_value(t, status, 0)
	state := run_executable(output)
	testing.expect_value(t, state.exit_code, 0)
}

@(test)
unused_invalid_global_does_not_trap :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-invalid-unused"
	defer _ = os.remove(output)
	status := compiler_core.compile_file("examples/invalid_unused_global.bro", output)
	testing.expect_value(t, status, 1)
	state := run_executable(output)
	testing.expect_value(t, state.exit_code, 0)
}

@(test)
used_invalid_global_traps :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-invalid-used"
	defer _ = os.remove(output)
	status := compiler_core.compile_file("examples/invalid_used_global.bro", output)
	testing.expect_value(t, status, 1)
	state := run_executable(output)
	testing.expect(t, !state.success)
}

@(test)
main_int_is_constrained_to_i32 :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-main-int"
	defer _ = os.remove(output)
	status := compiler_core.compile_file("examples/main_int.bro", output)
	testing.expect_value(t, status, 0)
	state := run_executable(output)
	testing.expect_value(t, state.exit_code, 3)
}

@(test)
main_i32_returns_directly :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-main-i32"
	defer _ = os.remove(output)
	status := compiler_core.compile_file("examples/main_i32.bro", output)
	testing.expect_value(t, status, 0)
	state := run_executable(output)
	testing.expect_value(t, state.exit_code, 4)
}

@(test)
transitive_problematic_global_is_deferred :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-transitive-unused"
	defer _ = os.remove(output)
	status := compiler_core.compile_file("examples/invalid_transitive_unused_global.bro", output)
	testing.expect_value(t, status, 1)
	state := run_executable(output)
	testing.expect_value(t, state.exit_code, 0)
}

@(test)
checked_addition_traps_on_overflow :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-overflow"
	defer _ = os.remove(output)
	status := compiler_core.compile_file("examples/overflow.bro", output)
	testing.expect_value(t, status, 0)
	state := run_executable(output)
	testing.expect(t, !state.success)
}

@(test)
constant_that_does_not_fit_context_produces_trap_executable :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-constant-context-error"
	defer _ = os.remove(output)
	status := compiler_core.compile_file("examples/constant_context_error.bro", output)
	testing.expect_value(t, status, 1)
	state := run_executable(output)
	testing.expect(t, !state.success)
}

@(test)
constant_beyond_i64_produces_trap_executable :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-constant-i64-overflow"
	defer _ = os.remove(output)
	status := compiler_core.compile_file("examples/constant_i64_overflow.bro", output)
	testing.expect_value(t, status, 1)
	state := run_executable(output)
	testing.expect(t, !state.success)
}

@(test)
same_line_statements_are_diagnosed :: proc(t: ^testing.T) {
	text := "main :: func() void { _ = 1 _ = 2\n}\n"
	source_file := source.Source{path="test.bro", text=text}
	diagnostics := source.init_diagnostics(&source_file)
	defer source.destroy_diagnostics(&diagnostics)
	stream := lexer.lex(&source_file, &diagnostics)
	defer delete(stream.items)
	module := parser.parse(&stream, &diagnostics)
	defer ast.destroy_module(&module)
	testing.expect(t, len(diagnostics.items) > 0)
}

@(test)
missing_main_produces_trap_executable :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-missing-main"
	defer _ = os.remove(output)
	status := compiler_core.compile_file("examples/missing_main.bro", output)
	testing.expect_value(t, status, 1)
	state := run_executable(output)
	testing.expect(t, !state.success)
}

@(test)
backend_failure_preserves_existing_output :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-preserved-output"
	defer _ = os.remove(output)
	previous := "previous artifact"
	testing.expect(t, os.write_entire_file(output, transmute([]byte)previous))
	testing.expect(t, !backend.compile("/definitely/not/llvm.ll", output))
	data, ok := os.read_entire_file(output)
	defer delete(data)
	testing.expect(t, ok)
	testing.expect_value(t, string(data), previous)
}

@(test)
mutable_local_reassignment_uses_runtime_storage :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-mutable"
	defer _ = os.remove(output)
	status := compiler_core.compile_file("examples/mutable_local.bro", output)
	testing.expect_value(t, status, 0)
	state := run_executable(output)
	testing.expect_value(t, state.exit_code, 3)
}

@(test)
implicit_narrowing_produces_trap_executable :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-narrowing"
	defer _ = os.remove(output)
	status := compiler_core.compile_file("examples/narrowing_error.bro", output)
	testing.expect_value(t, status, 1)
	state := run_executable(output)
	testing.expect(t, !state.success)
}

@(test)
valid_runtime_global_initializes_before_main :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-runtime-global"
	defer _ = os.remove(output)
	status := compiler_core.compile_file("examples/runtime_global.bro", output)
	testing.expect_value(t, status, 0)
	state := run_executable(output)
	testing.expect_value(t, state.exit_code, 0)
}

@(test)
unused_global_cycle_is_deferred :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-cycle-unused"
	defer _ = os.remove(output)
	status := compiler_core.compile_file("examples/cycle_unused.bro", output)
	testing.expect_value(t, status, 1)
	state := run_executable(output)
	testing.expect_value(t, state.exit_code, 0)
}

@(test)
used_global_cycle_traps :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-cycle-used"
	defer _ = os.remove(output)
	status := compiler_core.compile_file("examples/cycle_used.bro", output)
	testing.expect_value(t, status, 1)
	state := run_executable(output)
	testing.expect(t, !state.success)
}

@(test)
malformed_typed_values_still_produce_executable :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-malformed-typed"
	defer _ = os.remove(output)
	status := compiler_core.compile_file("examples/malformed_typed_recovery.bro", output)
	testing.expect_value(t, status, 1)
	state := run_executable(output)
	testing.expect(t, !state.success)
}

@(test)
unused_invalid_function_is_diagnosed_but_not_reached :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-invalid-unused-function"
	defer _ = os.remove(output)
	status := compiler_core.compile_file("examples/invalid_unused_function.bro", output)
	testing.expect_value(t, status, 1)
	state := run_executable(output)
	testing.expect_value(t, state.exit_code, 0)
}

@(test)
function_mediated_problematic_global_is_deferred :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-function-global-unused"
	defer _ = os.remove(output)
	status := compiler_core.compile_file("examples/function_global_unused.bro", output)
	testing.expect_value(t, status, 1)
	state := run_executable(output)
	testing.expect_value(t, state.exit_code, 0)
}

@(test)
function_mediated_problematic_global_traps_when_used :: proc(t: ^testing.T) {
	output := "/tmp/brolang-test-function-global-used"
	defer _ = os.remove(output)
	status := compiler_core.compile_file("examples/function_global_used.bro", output)
	testing.expect_value(t, status, 1)
	state := run_executable(output)
	testing.expect(t, !state.success)
}