// Copyright (c) 2021 Lars Pontoppidan. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
module toml

// Pretty much all the same builtin types as the `json2.Any` type plus `DateTime`,`Date`,`Time`
pub type Any = Date
    | DateTime
    | Null
    | Time
    | []Any
    | bool
    | f32
    | f64
    | i64
    | int
    | map[string]Any
    | string
    | u64

// string returns `Any` as a string.
pub fn (a Any) string() string {
    match a {
        // NOTE if `.clone()` is not used here:
        // string { return a as string }
        // ... certain call-patterns to this function will cause a memory corruption.
        // See `tests/toml_memory_corruption_test.v` for a matching regression test.
        string { return (a as string).clone() }
        DateTime { return a.str().clone() }
        Date { return a.str().clone() }
        Time { return a.str().clone() }
        else { return a.str().clone() }
    }
}

// to_toml returns `Any` as a TOML encoded value.
pub fn (a Any) to_toml() string {
    match a {
        map[string]Any {
            // TODO: more format control?
            return a.to_inline_toml()
        }
        []Any {
            return a.to_toml()
        }
        bool, f32, f64, i64, int, u64 {
            return a.str().clone()
        }
        // NOTE if `.clone()` is not used here:
        // string { return a as string }
        // ... certain call-patterns to this function will cause a memory corruption.
        // See `tests/toml_memory_corruption_test.v` for a matching regression test.
        string {
            return '"' + (a as string).clone() + '"'
        }
        DateTime {
            return a.str().clone()
        }
        Date {
            return a.str().clone()
        }
        Time {
            return a.str().clone()
        }
        else {
            return a.str().clone()
        }
    }
}

// int returns `Any` as an 32-bit integer.
pub fn (a Any) int() int {
    match a {
        int { return a }
        i64, f32, f64, bool { return int(a) }
        // time.Time { return int(0) } // TODO
        else { return 0 }
    }
}

// i64 returns `Any` as a 64-bit integer.
pub fn (a Any) i64() i64 {
    match a {
        i64 { return a }
        int, f32, f64, bool { return i64(a) }
        // time.Time { return i64(0) } // TODO
        else { return 0 }
    }
}

// u64 returns `Any` as a 64-bit unsigned integer.
pub fn (a Any) u64() u64 {
    match a {
        u64 { return a }
        int, i64, f32, f64, bool { return u64(a) }
        // time.Time { return u64(0) } // TODO
        else { return 0 }
    }
}

// f32 returns `Any` as a 32-bit float.
pub fn (a Any) f32() f32 {
    match a {
        f32 { return a }
        int, i64, f64 { return f32(a) }
        // time.Time { return f32(0) } // TODO
        else { return 0.0 }
    }
}

// f64 returns `Any` as a 64-bit float.
pub fn (a Any) f64() f64 {
    match a {
        f64 { return a }
        int, i64, f32 { return f64(a) }
        // time.Time { return f64(0) } // TODO
        else { return 0.0 }
    }
}

// array returns `Any` as an array.
pub fn (a Any) array() []Any {
    if a is []Any {
        return a
    } else if a is map[string]Any {
        mut arr := []Any{}
        for _, v in a {
            arr << v
        }
        return arr
    }
    return [a]
}

// as_map returns `Any` as a map (TOML table).
pub fn (a Any) as_map() map[string]Any {
    if a is map[string]Any {
        return a
    } else if a is []Any {
        mut mp := map[string]Any{}
        for i, fi in a {
            mp['${i}'] = fi
        }
        return mp
    }
    return {
        '0': a
    }
}

// bool returns `Any` as a boolean.
pub fn (a Any) bool() bool {
    match a {
        bool { return a }
        string { return a.bool() }
        else { return false }
    }
}

// date returns `Any` as a `toml.Date` struct.
pub fn (a Any) date() Date {
    match a {
        // string {  } // TODO
        // NOTE `.clone()` is to avoid memory corruption see `pub fn (a Any) string() string`
        Date { return Date{a.str().clone()} }
        else { return Date{''} }
    }
}

// time returns `Any` as a `toml.Time` struct.
pub fn (a Any) time() Time {
    match a {
        // string {  } // TODO
        // NOTE `.clone()` is to avoid memory corruption see `pub fn (a Any) string() string`
        Time { return Time{a.str().clone()} }
        else { return Time{''} }
    }
}

// datetime returns `Any` as a `toml.DateTime` struct.
pub fn (a Any) datetime() DateTime {
    match a {
        // string {  } // TODO
        // NOTE `.clone()` is to avoid memory corruption see `pub fn (a Any) string() string`
        DateTime { return DateTime{a.str().clone()} }
        else { return DateTime{''} }
    }
}

// default_to returns `value` if `a Any` is `Null`.
// This can be used to set default values when retrieving
// values. E.g.: `toml_doc.value('wrong.key').default_to(123).int()`
pub fn (a Any) default_to(value Any) Any {
    match a {
        Null { return value }
        else { return a }
    }
}

// value queries a value from the map.
// `key` supports a small query syntax scheme:
// Maps can be queried in "dotted" form e.g. `a.b.c`.
// quoted keys are supported as `a."b.c"` or `a.'b.c'`.
// Arrays can be queried with `a[0].b[1].[2]`.
pub fn (m map[string]Any) value(key string) Any {
    return Any(m).value(key)
}

// as_strings returns the contents of the map
// as `map[string]string`
pub fn (m map[string]Any) as_strings() map[string]string {
    mut result := map[string]string{}
    for k, v in m {
        result[k] = v.string()
    }
    return result
}

// to_toml returns the contents of the map
// as a TOML encoded `string`.
pub fn (m map[string]Any) to_toml() string {
    mut toml_text := ''
    for k, v in m {
        key := if k.contains(' ') { '"${k}"' } else { k }
        toml_text += '${key} = ${v.to_toml()}\n'
    }
    toml_text = toml_text.trim_right('\n')
    return toml_text
}

// to_inline_toml returns the contents of the map
// as an inline table encoded TOML `string`.
pub fn (m map[string]Any) to_inline_toml() string {
    mut toml_text := '{'
    mut i := 1
    for k, v in m {
        key := if k.contains(' ') { '"${k}"' } else { k }
        delimiter := if i < m.len { ',' } else { '' }
        toml_text += ' ${key} = ${v.to_toml()}${delimiter}'
        i++
    }
    return toml_text + ' }'
}

// value queries a value from the array.
// `key` supports a small query syntax scheme:
// The array can be queried with `[0].b[1].[2]`.
// Maps can be queried in "dotted" form e.g. `a.b.c`.
// quoted keys are supported as `a."b.c"` or `a.'b.c'`.
pub fn (a []Any) value(key string) Any {
    return Any(a).value(key)
}

// as_strings returns the contents of the array
// as `[]string`
pub fn (a []Any) as_strings() []string {
    mut sa := []string{}
    for any in a {
        sa << any.string()
    }
    return sa
}

// to_toml returns the contents of the array
// as a TOML encoded `string`.
pub fn (a []Any) to_toml() string {
    mut toml_text := '[\n'
    for any in a {
        toml_text += '  ' + any.to_toml() + ',\n'
    }
    toml_text = toml_text.trim_right(',\n')
    return toml_text + '\n]'
}

// value queries a value from the `Any` type.
// `key` supports a small query syntax scheme:
// Maps can be queried in "dotted" form e.g. `a.b.c`.
// quoted keys are supported as `a."b.c"` or `a.'b.c'`.
// Arrays can be queried with `a[0].b[1].[2]`.
pub fn (a Any) value(key string) Any {
    key_split := parse_dotted_key(key) or { return null }
    return a.value_(a, key_split)
}

// value_opt queries a value from the current element's tree. Returns an error
// if the key is not valid or there is no value for the key.
pub fn (a Any) value_opt(key string) !Any {
    key_split := parse_dotted_key(key) or { return error('invalid dotted key') }
    x := a.value_(a, key_split)
    if x is Null {
        return error('no value for key')
    }
    return x
}

// value_ returns the `Any` value found at `key`.
fn (a Any) value_(value Any, key []string) Any {
    if key.len == 0 {
        return null
    }
    mut any_value := null
    k, index := parse_array_key(key[0])
    if k == '' {
        arr := value as []Any
        any_value = arr[index] or { return null }
    }
    if value is map[string]Any {
        any_value = value[k] or { return null }
        if index > -1 {
            arr := any_value as []Any
            any_value = arr[index] or { return null }
        }
    }
    if key.len <= 1 {
        return any_value
    }
    match any_value {
        map[string]Any, []Any {
            return a.value_(any_value, key[1..])
        }
        else {
            return value
        }
    }
}

// reflect returns `T` with `T.<field>`'s value set to the
// value of any 1st level TOML key by the same name.
pub fn (a Any) reflect[T]() T {
    mut reflected := T{}
    $for field in T.fields {
        mut toml_field_name := field.name
        mut skip := false
        // Remapping of field names, for example:
        // TOML: 'assert = "ok"'
        // V:    User { asrt string @[toml: 'assert'] }
        // User.asrt == 'ok'
        for attr in field.attrs {
            if attr == 'skip' {
                skip = true
                break
            }
            if attr.starts_with('toml:') {
                toml_field_name = attr.all_after(':').trim_space()
            }
        }
        value := a.value(toml_field_name)
        // only set the field's value when value != null and !skip, else field got it's default value
        if !skip && value != null {
            $if field.typ is string {
                reflected.$(field.name) = value.string()
            } $else $if field.typ is bool {
                reflected.$(field.name) = value.bool()
            } $else $if field.typ is int {
                reflected.$(field.name) = value.int()
            } $else $if field.typ is f32 {
                reflected.$(field.name) = value.f32()
            } $else $if field.typ is f64 {
                reflected.$(field.name) = value.f64()
            } $else $if field.typ is i64 {
                reflected.$(field.name) = value.i64()
            } $else $if field.typ is u64 {
                reflected.$(field.name) = value.u64()
            } $else $if field.typ is Any {
                reflected.$(field.name) = value
            } $else $if field.typ is DateTime {
                reflected.$(field.name) = value.datetime()
            } $else $if field.typ is Date {
                reflected.$(field.name) = value.date()
            } $else $if field.typ is Time {
                reflected.$(field.name) = value.time()
            }
            // Arrays of primitive types
            $else $if field.typ is []string {
                any_array := value.array()
                reflected.$(field.name) = any_array.as_strings()
            } $else $if field.typ is []bool {
                any_array := value.array()
                mut arr := []bool{cap: any_array.len}
                for any_value in any_array {
                    arr << any_value.bool()
                }
                reflected.$(field.name) = arr
            } $else $if field.typ is []int {
                any_array := value.array()
                mut arr := []int{cap: any_array.len}
                for any_value in any_array {
                    arr << any_value.int()
                }
                reflected.$(field.name) = arr
            } $else $if field.typ is []f32 {
                any_array := value.array()
                mut arr := []f32{cap: any_array.len}
                for any_value in any_array {
                    arr << any_value.f32()
                }
                reflected.$(field.name) = arr
            } $else $if field.typ is []f64 {
                any_array := value.array()
                mut arr := []f64{cap: any_array.len}
                for any_value in any_array {
                    arr << any_value.f64()
                }
                reflected.$(field.name) = arr
            } $else $if field.typ is []i64 {
                any_array := value.array()
                mut arr := []i64{cap: any_array.len}
                for any_value in any_array {
                    arr << any_value.i64()
                }
                reflected.$(field.name) = arr
            } $else $if field.typ is []u64 {
                any_array := value.array()
                mut arr := []u64{cap: any_array.len}
                for any_value in any_array {
                    arr << any_value.u64()
                }
                reflected.$(field.name) = arr
            } $else $if field.typ is []Any {
                reflected.$(field.name) = value.array()
            } $else $if field.typ is []DateTime {
                any_array := value.array()
                mut arr := []DateTime{cap: any_array.len}
                for any_value in any_array {
                    arr << any_value.datetime()
                }
                reflected.$(field.name) = arr
            } $else $if field.typ is []Date {
                any_array := value.array()
                mut arr := []Date{cap: any_array.len}
                for any_value in any_array {
                    arr << any_value.date()
                }
                reflected.$(field.name) = arr
            } $else $if field.typ is []Time {
                any_array := value.array()
                mut arr := []Time{cap: any_array.len}
                for any_value in any_array {
                    arr << any_value.time()
                }
                reflected.$(field.name) = arr
            }
            // String key maps of primitive types
            $else $if field.typ is map[string]string {
                any_map := value.as_map()
                reflected.$(field.name) = any_map.as_strings()
            } $else $if field.typ is map[string]bool {
                any_map := value.as_map()
                mut type_map := map[string]bool{}
                for k, any_value in any_map {
                    type_map[k] = any_value.bool()
                }
                reflected.$(field.name) = type_map.clone()
            } $else $if field.typ is map[string]int {
                any_map := value.as_map()
                mut type_map := map[string]int{}
                for k, any_value in any_map {
                    type_map[k] = any_value.int()
                }
                reflected.$(field.name) = type_map.clone()
            } $else $if field.typ is map[string]f32 {
                any_map := value.as_map()
                mut type_map := map[string]f32{}
                for k, any_value in any_map {
                    type_map[k] = any_value.f32()
                }
                reflected.$(field.name) = type_map.clone()
            } $else $if field.typ is map[string]f64 {
                any_map := value.as_map()
                mut type_map := map[string]f64{}
                for k, any_value in any_map {
                    type_map[k] = any_value.f64()
                }
                reflected.$(field.name) = type_map.clone()
            } $else $if field.typ is map[string]i64 {
                any_map := value.as_map()
                mut type_map := map[string]i64{}
                for k, any_value in any_map {
                    type_map[k] = any_value.i64()
                }
                reflected.$(field.name) = type_map.clone()
            } $else $if field.typ is map[string]u64 {
                any_map := value.as_map()
                mut type_map := map[string]u64{}
                for k, any_value in any_map {
                    type_map[k] = any_value.u64()
                }
                reflected.$(field.name) = type_map.clone()
            } $else $if field.typ is map[string]Any {
                reflected.$(field.name) = value.as_map()
            } $else $if field.typ is map[string]DateTime {
                any_map := value.as_map()
                mut type_map := map[string]DateTime{}
                for k, any_value in any_map {
                    type_map[k] = any_value.datetime()
                }
                reflected.$(field.name) = type_map.clone()
            } $else $if field.typ is map[string]Date {
                any_map := value.as_map()
                mut type_map := map[string]Date{}
                for k, any_value in any_map {
                    type_map[k] = any_value.date()
                }
                reflected.$(field.name) = type_map.clone()
            } $else $if field.typ is map[string]Time {
                any_map := value.as_map()
                mut type_map := map[string]Time{}
                for k, any_value in any_map {
                    type_map[k] = any_value.time()
                }
                reflected.$(field.name) = type_map.clone()
            }
        }
    }
    return reflected
}