// Copyright (c) 2019-2023 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
[has_globals]
module builtin

// isnil returns true if an object is nil (only for C objects).
[inline]
pub fn isnil(v voidptr) bool {
    return v == 0
}

/*
fn on_panic(f fn(int)int) {
    // TODO
}
*/

struct VCastTypeIndexName {
    tindex int
    tname  string
}

// will be filled in cgen
__global as_cast_type_indexes []VCastTypeIndexName

fn __as_cast(obj voidptr, obj_type int, expected_type int) voidptr {
    if obj_type != expected_type {
        mut obj_name := as_cast_type_indexes[0].tname.clone()
        mut expected_name := as_cast_type_indexes[0].tname.clone()
        for x in as_cast_type_indexes {
            if x.tindex == obj_type {
                obj_name = x.tname.clone()
            }
            if x.tindex == expected_type {
                expected_name = x.tname.clone()
            }
        }
        panic('as cast: cannot cast `${obj_name}` to `${expected_name}`')
    }
    return obj
}

// VAssertMetaInfo is used during assertions. An instance of it is filled in by
// compile time generated code, when an assertion fails.
pub struct VAssertMetaInfo {
pub:
    fpath   string // the source file path of the assertion
    line_nr int    // the line number of the assertion
    fn_name string // the function name in which the assertion is
    src     string // the actual source line of the assertion
    op      string // the operation of the assertion, i.e. '==', '<', 'call', etc ...
    llabel  string // the left side of the infix expressions as source
    rlabel  string // the right side of the infix expressions as source
    lvalue  string // the stringified *actual value* of the left side of a failed assertion
    rvalue  string // the stringified *actual value* of the right side of a failed assertion
    message string // the value of the `message` from `assert cond, message`
    has_msg bool   // false for assertions like `assert cond`, true for `assert cond, 'oh no'`
}

// free frees the memory occupied by the assertion meta data. It is called automatically by
// the code, that V's test framework generates, after all other callbacks have been called.
[manualfree; unsafe]
pub fn (ami &VAssertMetaInfo) free() {
    unsafe {
        ami.fpath.free()
        ami.fn_name.free()
        ami.src.free()
        ami.op.free()
        ami.llabel.free()
        ami.rlabel.free()
        ami.lvalue.free()
        ami.rvalue.free()
        ami.message.free()
    }
}

fn __print_assert_failure(i &VAssertMetaInfo) {
    eprintln('${i.fpath}:${i.line_nr + 1}: FAIL: fn ${i.fn_name}: assert ${i.src}')
    if i.op.len > 0 && i.op != 'call' {
        eprintln('   left value: ${i.llabel} = ${i.lvalue}')
        if i.rlabel == i.rvalue {
            eprintln('  right value: ${i.rlabel}')
        } else {
            eprintln('  right value: ${i.rlabel} = ${i.rvalue}')
        }
    }
    if i.has_msg {
        eprintln('      message: ${i.message}')
    }
}

// MethodArgs holds type information for function and/or method arguments.
pub struct MethodArgs {
pub:
    typ  int
    name string
}

// FunctionData holds information about a parsed function.
pub struct FunctionData {
pub:
    name        string
    attrs       []string
    args        []MethodArgs
    return_type int
    typ         int
}

pub struct EnumData {
pub:
    name  string
    value i64
    attrs []string
}

// FieldData holds information about a field. Fields reside on structs.
pub struct FieldData {
pub:
    name          string // the name of the field f
    typ           int    // the internal TypeID of the field f,
    unaliased_typ int    // if f's type was an alias of int, this will be TypeID(int)
    //
    attrs  []string // the attributes of the field f
    is_pub bool     // f is in a `pub:` section
    is_mut bool     // f is in a `mut:` section
    //
    is_shared bool // `f shared Abc`
    is_atomic bool // `f atomic int` , TODO
    is_option bool // `f ?string` , TODO
    //
    is_array  bool // `f []string` , TODO
    is_map    bool // `f map[string]int` , TODO
    is_chan   bool // `f chan int` , TODO
    is_enum   bool // `f Enum` where Enum is an enum
    is_struct bool // `f Abc` where Abc is a struct , TODO
    is_alias  bool // `f MyInt` where `type MyInt = int`, TODO
    //
    indirections u8 // 0 for `f int`, 1 for `f &int`, 2 for `f &&int` , TODO
}

pub enum AttributeKind {
    plain // [name]
    string // ['name']
    number // [123]
    comptime_define // [if name]
}

pub struct StructAttribute {
pub:
    name    string
    has_arg bool
    arg     string
    kind    AttributeKind
}