# This file is a part of Julia. License is MIT: https://julialang.org/license

## SubString, RevString and Cstring tests ##

## SubString tests ##
u8str = "∀ ε > 0, ∃ δ > 0: |x-y| < δ ⇒ |f(x)-f(y)| < ε"
u8str2 = u8str^2
len_u8str = length(u8str)
slen_u8str = length(u8str)
len_u8str2 = length(u8str2)
slen_u8str2 = length(u8str2)

@test len_u8str2 == 2 * len_u8str
@test slen_u8str2 == 2 * slen_u8str

u8str2plain = String(u8str2)

for i1 = 1:length(u8str2)
    if !isvalid(u8str2, i1); continue; end
    for i2 = i1:length(u8str2)
        if !isvalid(u8str2, i2); continue; end
        @test length(u8str2[i1:i2]) == length(u8str2plain[i1:i2])
        @test length(u8str2[i1:i2]) == length(u8str2plain[i1:i2])
        @test u8str2[i1:i2] == u8str2plain[i1:i2]
    end
end

# tests that SubString of a single multibyte `Char` string, like "∀" which takes 3 bytes
# gives the same result as `getindex` (except that it is a veiw not a copy)
for idx in 0:1
    @test SubString("∀", 1, idx) == "∀"[1:idx]
end

# Substring provided with invalid end index throws BoundsError
@test_throws BoundsError SubString("∀", 1, 2)
@test_throws BoundsError SubString("∀", 1, 3)
@test_throws BoundsError SubString("∀", 1, 4)

# Substring provided with invalid start index throws BoundsError
@test_throws BoundsError SubString("∀∀", 2:4)

# tests for SubString of more than one multibyte `Char` string
# we are consistent with `getindex` for `String`
for idx in [0, 1, 4]
    @test SubString("∀∀", 1, idx) == "∀∀"[1:idx]
    @test SubString("∀∀", 4, idx) == "∀∀"[4:idx]
end

# second index beyond endof("∀∀")
for idx in 5:8
    @test_throws BoundsError SubString("∀∀", 1, idx)
    @test_throws BoundsError SubString("∀∀", 4, idx)
end

let str="tempus fugit"              #length(str)==12
    ss=SubString(str,1,endof(str)) #match source string
    @test length(ss)==length(str)

    ss=SubString(str,1:endof(str))
    @test length(ss)==length(str)

    ss=SubString(str,1,0)    #empty SubString
    @test length(ss)==0

    ss=SubString(str,1:0)
    @test length(ss)==0

    @test_throws BoundsError SubString(str,14,20)  #start indexing beyond source string length
    @test_throws BoundsError SubString(str,10,16)  #end indexing beyond source string length

    @test_throws BoundsError SubString("", 1, 4)  #empty source string
    @test_throws BoundsError SubString("", 1, 1)  #empty source string, identical start and end index
    @test_throws BoundsError SubString("", 10, 12)
    @test SubString("",12,10) == ""
end

@test SubString("foobar", big(1), big(3)) == "foo"

let str = "aa\u2200\u2222bb"
    u = SubString(str, 3, 6)
    @test length(u) == 2
    b = IOBuffer()
    write(b, u)
    @test String(take!(b)) == "\u2200\u2222"

    @test_throws BoundsError SubString(str, 4, 5)
    @test_throws BoundsError next(u, 0)
    @test_throws BoundsError next(u, 7)
    @test_throws BoundsError getindex(u, 0)
    @test_throws BoundsError getindex(u, 7)
    @test_throws BoundsError getindex(u, 0:1)
    @test_throws BoundsError getindex(u, 7:7)
    @test reverseind(u, 1) == 4
    @test typeof(Base.cconvert(Ptr{Int8}, u)) == SubString{String}
    @test Base.cconvert(Ptr{Int8}, u) == u
end

let str = "føøbar"
    @test_throws BoundsError SubString(str, 10, 10)
    u = SubString(str, 4, 3)
    @test length(u) == 0
    b = IOBuffer()
    write(b, u)
    @test String(take!(b)) == ""
end

# search and SubString (issue #5679)
let str = "Hello, world!"
    u = SubString(str, 1, 5)
    @test rsearch(u, "World") == 0:-1
    @test rsearch(u, 'z') == 0
    @test rsearch(u, "ll") == 3:4
end

# SubString created from SubString
let str = "Hello, world!"
    u = SubString(str, 2, 5)
    for idx in 1:4
        @test SubString(u, 2, idx) == u[2:idx]
        @test SubString(u, 2:idx) == u[2:idx]
    end
    @test_throws BoundsError SubString(u, 1, 10)
    @test_throws BoundsError SubString(u, 1:10)
    @test_throws BoundsError SubString(u, 20:30)
    @test SubString(u, 20:15) == ""
    @test_throws BoundsError SubString(u, -1:10)
    @test SubString(u, -1, -10) == ""
    @test SubString(SubString("123", 1, 2), -10, -20) == ""
end

# sizeof
@test sizeof(SubString("abc\u2222def",4,4)) == 3

# issue #3710
@test prevind(SubString("{var}",2,4),4) == 3

# issue #4183
@test split(SubString("x", 2, 0), "y") == AbstractString[""]

# issue #6772
@test parse(Float64, SubString("10",1,1)) === 1.0
@test parse(Float64, SubString("1 0",1,1)) === 1.0
@test parse(Float32, SubString("10",1,1)) === 1.0f0

# issue #5870
@test !ismatch(Regex("aa"), SubString("",1,0))
@test ismatch(Regex(""), SubString("",1,0))

# isvalid(), chr2ind() and ind2chr() for SubString{String}
let ss, s="lorem ipsum",
    sdict=Dict(SubString(s,1,11)=>s,
               SubString(s,1,6)=>"lorem ",
               SubString(s,1,0)=>"",
               SubString(s,2,4)=>"ore",
               SubString(s,2,11)=>"orem ipsum",
               SubString(s,15,14)=>""
               )
    for (ss,s) in sdict
        local ss
        for i in -1:12
            @test isvalid(ss,i)==isvalid(s,i)
        end
    end
    for (ss,s) in sdict
        local ss
        for i in 1:length(ss)
            @test ind2chr(ss,i)==ind2chr(s,i)
        end
    end
    for (ss,s) in sdict
        local ss
        for i in 1:length(ss)
            @test chr2ind(ss,i)==chr2ind(s,i)
        end
    end
end #let

#for isvalid(SubString{String})
let s = "Σx + βz - 2"
    for i in -1:(length(s)+2)
        if isvalid(s, i)
            ss=SubString(s,1,i)
            # make sure isvalid gives equivalent results for SubString and String
            @test isvalid(ss,i)==isvalid(s,i)
        else
            if i > 0
                @test_throws BoundsError SubString(s,1,i)
            else
                @test SubString(s,1,i) == ""
            end
        end
    end
end

let ss=SubString("hello",1,5)
    @test_throws BoundsError ind2chr(ss, -1)
    @test_throws BoundsError chr2ind(ss, -1)
    @test_throws BoundsError chr2ind(ss, 10)
    @test_throws BoundsError ind2chr(ss, 10)
end

# length(SubString{String}) performance specialization
let s = "|η(α)-ϕ(κ)| < ε"
    @test length(SubString(s,1,0))==length(s[1:0])
    @test length(SubString(s,4,4))==length(s[4:4])
    @test length(SubString(s,1,7))==length(s[1:7])
    @test length(SubString(s,4,11))==length(s[4:11])
end

## Reverse strings ##

let rs = RevString("foobar")
    @test length(rs) == 6
    @test sizeof(rs) == 6
    @test isascii(rs)
end

# issue #4586
@test rsplit(RevString("ailuj"),'l') == ["ju","ia"]
@test parse(Float64,RevString("64")) === 46.0

# reverseind
for T in (String, GenericString)
    for prefix in ("", "abcd", "\U0001d6a4\U0001d4c1", "\U0001d6a4\U0001d4c1c", " \U0001d6a4\U0001d4c1")
        for suffix in ("", "abcde", "\U0001d4c1β\U0001d6a4", "\U0001d4c1β\U0001d6a4c", " \U0001d4c1β\U0001d6a4")
            for c in ('X', 'δ', '\U0001d6a5')
                s = convert(T, string(prefix, c, suffix))
                r = reverse(s)
                ri = search(r, c)
                @test r == RevString(s)
                @test c == s[reverseind(s, ri)] == r[ri]
                s = RevString(s)
                r = reverse(s)
                ri = search(r, c)
                @test c == s[reverseind(s, ri)] == r[ri]
                s = convert(T, string(prefix, prefix, c, suffix, suffix))
                pre = convert(T, prefix)
                sb = SubString(s, nextind(pre, endof(pre)), endof(convert(T, string(prefix, prefix, c, suffix))))
                r = reverse(sb)
                ri = search(r, c)
                @test c == sb[reverseind(sb, ri)] == r[ri]
            end
        end
    end
end

## Cstring tests ##

# issue #13974: comparison against pointers
let
    str = String("foobar")
    ptr = pointer(str)
    cstring = Cstring(ptr)
    @test ptr == cstring
    @test cstring == ptr

    # convenient NULL string creation from Ptr{Void}
    nullstr = Cstring(C_NULL)

    # Comparisons against NULL strings
    @test ptr != nullstr
    @test nullstr != ptr

    # Short-hand comparison against C_NULL
    @test nullstr == C_NULL
    @test C_NULL == nullstr
    @test cstring != C_NULL
    @test C_NULL != cstring
end