1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
use std::ptr::NonNull;
use std::slice::from_raw_parts;
use std::str::from_utf8;
use std::sync::Arc;

use libsqlite3_sys::{
    sqlite3_value, sqlite3_value_blob, sqlite3_value_bytes, sqlite3_value_double,
    sqlite3_value_dup, sqlite3_value_free, sqlite3_value_int, sqlite3_value_int64,
    sqlite3_value_type, SQLITE_NULL,
};

use crate::type_info::DataType;
use crate::SqliteTypeInfo;
use rbdc::error::Error;
use std::borrow::Cow;

enum SqliteValueData<'r> {
    Value(&'r SqliteValue),
}

pub struct SqliteValueRef<'r>(SqliteValueData<'r>);

impl<'r> SqliteValueRef<'r> {
    pub(crate) fn value(value: &'r SqliteValue) -> Self {
        Self(SqliteValueData::Value(value))
    }

    pub(super) fn int(&self) -> i32 {
        match self.0 {
            SqliteValueData::Value(v) => v.int(),
        }
    }

    pub(super) fn int64(&self) -> i64 {
        match self.0 {
            SqliteValueData::Value(v) => v.int64(),
        }
    }

    pub(super) fn double(&self) -> f64 {
        match self.0 {
            SqliteValueData::Value(v) => v.double(),
        }
    }

    pub(super) fn blob(&self) -> &'r [u8] {
        match self.0 {
            SqliteValueData::Value(v) => v.blob(),
        }
    }

    pub(super) fn text(&self) -> Result<&'r str, Error> {
        match self.0 {
            SqliteValueData::Value(v) => v.text(),
        }
    }
}

impl<'r> SqliteValueRef<'r> {
    pub fn to_owned(&self) -> SqliteValue {
        match self.0 {
            SqliteValueData::Value(v) => v.clone(),
        }
    }

    pub fn type_info(&self) -> Cow<'_, SqliteTypeInfo> {
        match self.0 {
            SqliteValueData::Value(v) => v.type_info(),
        }
    }

    pub fn is_null(&self) -> bool {
        match self.0 {
            SqliteValueData::Value(v) => v.is_null(),
        }
    }
}

#[derive(Clone, Debug)]
pub struct SqliteValue {
    pub(crate) handle: Arc<ValueHandle>,
    pub(crate) type_info: SqliteTypeInfo,
}

#[derive(Debug)]
pub(crate) struct ValueHandle(NonNull<sqlite3_value>);

// SAFE: only protected value objects are stored in SqliteValue
unsafe impl Send for ValueHandle {}
unsafe impl Sync for ValueHandle {}

impl SqliteValue {
    pub(crate) unsafe fn new(value: *mut sqlite3_value, type_info: SqliteTypeInfo) -> Self {
        debug_assert!(!value.is_null());

        Self {
            type_info,
            handle: Arc::new(ValueHandle(NonNull::new_unchecked(sqlite3_value_dup(
                value,
            )))),
        }
    }

    pub fn type_info_opt(&self) -> Option<SqliteTypeInfo> {
        let dt = DataType::from_code(unsafe { sqlite3_value_type(self.handle.0.as_ptr()) });

        if let DataType::Null = dt {
            None
        } else {
            Some(SqliteTypeInfo(dt))
        }
    }

    pub fn int(&self) -> i32 {
        unsafe { sqlite3_value_int(self.handle.0.as_ptr()) }
    }

    pub fn int64(&self) -> i64 {
        unsafe { sqlite3_value_int64(self.handle.0.as_ptr()) }
    }

    pub fn double(&self) -> f64 {
        unsafe { sqlite3_value_double(self.handle.0.as_ptr()) }
    }

    pub fn blob(&self) -> &[u8] {
        let len = unsafe { sqlite3_value_bytes(self.handle.0.as_ptr()) } as usize;

        if len == 0 {
            // empty blobs are NULL so just return an empty slice
            return &[];
        }

        let ptr = unsafe { sqlite3_value_blob(self.handle.0.as_ptr()) } as *const u8;
        debug_assert!(!ptr.is_null());

        unsafe { from_raw_parts(ptr, len) }
    }

    pub fn text(&self) -> Result<&str, Error> {
        Ok(from_utf8(self.blob())?)
    }
}

impl SqliteValue {
    pub fn as_ref(&self) -> SqliteValueRef<'_> {
        SqliteValueRef::value(self)
    }

    pub fn type_info(&self) -> Cow<'_, SqliteTypeInfo> {
        self.type_info_opt()
            .map(Cow::Owned)
            .unwrap_or(Cow::Borrowed(&self.type_info))
    }

    pub fn is_null(&self) -> bool {
        unsafe { sqlite3_value_type(self.handle.0.as_ptr()) == SQLITE_NULL }
    }
}

impl Drop for ValueHandle {
    fn drop(&mut self) {
        unsafe {
            sqlite3_value_free(self.0.as_ptr());
        }
    }
}