// Copyright (c) 2019-2024 Felipe Pena. All rights reserved.
// Use of this source code is governed by an MIT license that can be found in the LICENSE file.
module checker

import v.ast

@[inline]
fn (mut c Checker) markused_comptime_call(check bool, key string) {
    if check {
        c.table.used_features.comptime_calls[key] = true
    }
}

fn comptime_call_last_arg_type(arg ast.CallArg) ast.Type {
    return if arg.expr is ast.ArrayDecompose {
        arg.expr.expr_type
    } else {
        arg.typ
    }
}

fn (mut c Checker) markused_assertstmt_auto_str(mut node ast.AssertStmt) {
    if !c.table.used_features.auto_str && !c.is_builtin_mod && mut node.expr is ast.InfixExpr {
        if !c.table.sym(c.unwrap_generic(node.expr.left_type)).has_method('str') {
            c.table.used_features.auto_str = true
            return
        }
        if !c.table.sym(c.unwrap_generic(node.expr.right_type)).has_method('str') {
            c.table.used_features.auto_str = true
        }
    }
}

fn (mut c Checker) markused_dumpexpr(mut node ast.DumpExpr) {
    if c.is_builtin_mod {
        return
    }
    unwrapped_type := c.unwrap_generic(node.expr_type)
    if node.expr_type.has_flag(.generic) {
        c.table.used_features.comptime_syms[unwrapped_type] = true
    }
    if !c.table.sym(unwrapped_type).has_method('str') {
        c.table.used_features.auto_str = true
        if node.expr_type.is_ptr() {
            c.table.used_features.auto_str_ptr = true
        }
        if !c.table.used_features.auto_str_arr {
            c.table.used_features.auto_str_arr = c.table.final_sym(unwrapped_type).kind == .array
        }
    } else {
        c.table.used_features.print_types[node.expr_type.idx()] = true
    }
    c.table.used_features.print_types[ast.int_type_idx] = true
}

@[inline]
fn (mut c Checker) markused_used_maps(check bool) {
    if check {
        c.table.used_features.used_maps++
    }
}

fn (mut c Checker) markused_castexpr(mut _ ast.CastExpr, _ ast.Type, mut final_to_sym ast.TypeSymbol) {
    if c.is_builtin_mod {
        return
    }
    if c.table.used_features.used_maps == 0 && mut final_to_sym.info is ast.SumType {
        if final_to_sym.info.variants.any(c.table.final_sym(it).kind == .map) {
            c.table.used_features.used_maps++
        }
    }
}

fn (mut c Checker) markused_comptimecall(mut node ast.ComptimeCall) {
    c.markused_comptime_call(true,
        '${int(c.unwrap_generic(c.comptime.comptime_for_method.receiver_type))}.${c.comptime.comptime_for_method.name}')
    if c.inside_anon_fn {
        // $method passed to anon fn, mark all methods as used
        sym := c.table.sym(c.unwrap_generic(node.left_type))
        for m in sym.get_methods() {
            c.table.used_features.comptime_calls['${int(c.unwrap_generic(m.receiver_type))}.${m.name}'] = true
            if node.args.len > 0 && m.params.len > 0 {
                last_param := m.params.last().typ
                last_arg_type := comptime_call_last_arg_type(node.args.last())
                if (last_param.is_int() || last_param.is_float()
                    || last_param.is_bool()) && c.table.final_sym(last_arg_type).kind == .array {
                    c.table.used_features.comptime_calls['${ast.string_type_idx}.${c.table.type_to_str(m.params.last().typ)}'] = true
                }
            }
        }
    } else {
        m := c.comptime.comptime_for_method
        if node.args.len > 0 && m.params.len > 0 {
            last_param := m.params.last().typ
            last_arg_type := comptime_call_last_arg_type(node.args.last())
            if (last_param.is_int() || last_param.is_float() || last_param.is_bool())
                && c.table.final_sym(last_arg_type).kind == .array {
                c.table.used_features.comptime_calls['${ast.string_type_idx}.${c.table.type_to_str(m.params.last().typ)}'] = true
            }
        }
    }
}

fn (mut c Checker) markused_comptimefor(mut _ ast.ComptimeFor, unwrapped_expr_type ast.Type) {
    if c.table.used_features.used_maps == 0 {
        final_sym := c.table.final_sym(unwrapped_expr_type)
        if final_sym.info is ast.Map {
            c.table.used_features.used_maps++
        } else if final_sym.info is ast.SumType {
            if final_sym.info.variants.any(c.table.final_sym(it).kind == .map) {
                c.table.used_features.used_maps++
            }
        }
    }
}

fn (mut c Checker) markused_call_expr(left_type ast.Type, mut node ast.CallExpr) {
    if left_type != 0 && left_type.is_ptr() && !c.table.used_features.auto_str_ptr
        && node.name == 'str' {
        c.table.used_features.auto_str_ptr = true
        if !c.table.used_features.auto_str_arr {
            c.table.used_features.auto_str_arr = c.table.final_sym(left_type).kind == .array
        }
    }
}

fn (mut c Checker) markused_print_call(mut node ast.CallExpr) {
    if !c.is_builtin_mod && c.mod != 'math.bits' && node.args[0].expr !is ast.StringLiteral {
        arg_typ := c.unwrap_generic(node.args[0].typ)
        if arg_typ == 0 {
            return
        }
        if (node.args[0].expr is ast.CallExpr && node.args[0].expr.is_method
            && node.args[0].expr.name == 'str')
            || !c.table.sym(arg_typ).has_method('str') {
            c.table.used_features.auto_str = true
        } else {
            c.mark_type_str_method_as_referenced(arg_typ)
            if arg_typ.has_option_or_result() {
                c.table.used_features.print_options = true
            }
            c.table.used_features.print_types[arg_typ.idx()] = true
            if !c.table.used_features.auto_str_ptr && node.args[0].expr is ast.Ident {
                var_obj := node.args[0].expr.obj
                if var_obj is ast.Var {
                    if var_obj.orig_type != 0 {
                        fsym := c.table.final_sym(var_obj.orig_type)
                        if fsym.kind == .interface {
                            c.table.used_features.auto_str_ptr = true
                        } else if fsym.kind == .array {
                            c.table.used_features.auto_str_arr = true
                        }
                        return
                    }
                }
            }
        }
        if arg_typ.is_ptr() {
            c.table.used_features.auto_str_ptr = true
        }
        if !c.table.used_features.auto_str_arr || !c.table.used_features.auto_str_ptr {
            sym := c.table.final_sym(arg_typ)
            if sym.kind == .array {
                c.table.used_features.auto_str_arr = true
            } else if sym.info is ast.Struct {
                if !c.table.used_features.auto_str_ptr {
                    c.table.used_features.auto_str_ptr = sym.info.fields.any(it.typ.is_ptr()
                        || it.typ.is_pointer())
                }
                c.table.used_features.auto_str_arr =
                    sym.info.fields.any(c.table.final_sym(it.typ).kind == .array)
            }
        }
    }
}

fn (mut c Checker) markused_method_call(mut node ast.CallExpr, mut left_expr ast.Expr, left_type ast.Type) {
    if !left_type.has_flag(.generic) && mut left_expr is ast.Ident {
        if left_expr.obj is ast.Var && left_expr.obj.ct_type_var == .smartcast {
            c.table.used_features.comptime_calls['${int(left_type)}.${node.name}'] = true
        }
        if c.table.sym(left_type).kind == .alias {
            c.table.used_features.comptime_calls['${int(left_type)}.${node.name}'] = true
            // Alias method calls can also auto-resolve to pointer receivers in cgen.
            if !left_type.is_ptr() {
                c.table.used_features.comptime_calls['${int(left_type.ref())}.${node.name}'] = true
            }
        }
    } else if left_type.has_flag(.generic) {
        unwrapped_left := c.unwrap_generic(left_type)
        c.table.used_features.comptime_calls['${int(unwrapped_left)}.${node.name}'] = true
        // Generic method calls can resolve to pointer receivers during cgen (`x.name()` -> `(&x).name()`).
        // Mark both forms so skip-unused does not drop pointer receiver methods.
        if !unwrapped_left.is_ptr() {
            c.table.used_features.comptime_calls['${int(unwrapped_left.ref())}.${node.name}'] = true
        }
    }
}

fn (mut c Checker) markused_string_inter_lit(mut _ ast.StringInterLiteral, ftyp ast.Type) {
    if c.is_builtin_mod {
        return
    }
    if !c.table.sym(ftyp).has_method('str') {
        c.table.used_features.auto_str = true
    } else {
        c.mark_type_str_method_as_referenced(ftyp)
        c.table.used_features.print_types[ftyp.idx()] = true
    }
    if ftyp.is_ptr() {
        c.table.used_features.auto_str_ptr = true
    }
    if !c.table.used_features.auto_str_arr {
        c.table.used_features.auto_str_arr = c.table.final_sym(ftyp).kind == .array
    }
    if ftyp.has_option_or_result() {
        c.table.used_features.print_options = true
    }
}

fn (mut c Checker) markused_array_method(check bool, method_name string) {
    if !check {
        return
    }
    match method_name {
        '' { // array init
        }
        'first' {
            c.table.used_features.arr_first = true
        }
        'last' {
            c.table.used_features.arr_last = true
        }
        'pop_left' {
            c.table.used_features.arr_pop_left = true
        }
        'pop' {
            c.table.used_features.arr_pop = true
        }
        'delete' {
            c.table.used_features.arr_delete = true
        }
        'map' {
            c.table.used_features.arr_map = true
        }
        else {}
    }
}