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
// Std
use std::io::Write;

// Internal
use app::parser::Parser;
use INTERNAL_ERROR_MSG;

pub struct PowerShellGen<'a, 'b>
where
    'a: 'b,
{
    p: &'b Parser<'a, 'b>,
}

impl<'a, 'b> PowerShellGen<'a, 'b> {
    pub fn new(p: &'b Parser<'a, 'b>) -> Self {
        PowerShellGen { p: p }
    }

    pub fn generate_to<W: Write>(&self, buf: &mut W) {
        let bin_name = self.p.meta.bin_name.as_ref().unwrap();

        let mut names = vec![];
        let subcommands_cases = generate_inner(self.p, "", &mut names);

        let result = format!(
            r#"
using namespace System.Management.Automation
using namespace System.Management.Automation.Language

Register-ArgumentCompleter -Native -CommandName '{bin_name}' -ScriptBlock {{
    param($wordToComplete, $commandAst, $cursorPosition)

    $commandElements = $commandAst.CommandElements
    $command = @(
        '{bin_name}'
        for ($i = 1; $i -lt $commandElements.Count; $i++) {{
            $element = $commandElements[$i]
            if ($element -isnot [StringConstantExpressionAst] -or
                $element.StringConstantType -ne [StringConstantType]::BareWord -or
                $element.Value.StartsWith('-')) {{
                break
        }}
        $element.Value
    }}) -join ';'

    $completions = @(switch ($command) {{{subcommands_cases}
    }})

    $completions.Where{{ $_.CompletionText -like "$wordToComplete*" }} |
        Sort-Object -Property ListItemText
}}
"#,
            bin_name = bin_name,
            subcommands_cases = subcommands_cases
        );

        w!(buf, result.as_bytes());
    }
}

// Escape string inside single quotes
fn escape_string(string: &str) -> String {
    string.replace("'", "''")
}

fn get_tooltip<T: ToString>(help: Option<&str>, data: T) -> String {
    match help {
        Some(help) => escape_string(help),
        _ => data.to_string(),
    }
}

fn generate_inner<'a, 'b, 'p>(
    p: &'p Parser<'a, 'b>,
    previous_command_name: &str,
    names: &mut Vec<&'p str>,
) -> String {
    debugln!("PowerShellGen::generate_inner;");
    let command_name = if previous_command_name.is_empty() {
        p.meta.bin_name.as_ref().expect(INTERNAL_ERROR_MSG).clone()
    } else {
        format!("{};{}", previous_command_name, &p.meta.name)
    };

    let mut completions = String::new();
    let preamble = String::from("\n            [CompletionResult]::new(");

    for option in p.opts() {
        if let Some(data) = option.s.short {
            let tooltip = get_tooltip(option.b.help, data);
            completions.push_str(&preamble);
            completions.push_str(
                format!(
                    "'-{}', '{}', {}, '{}')",
                    data, data, "[CompletionResultType]::ParameterName", tooltip
                )
                .as_str(),
            );
        }
        if let Some(data) = option.s.long {
            let tooltip = get_tooltip(option.b.help, data);
            completions.push_str(&preamble);
            completions.push_str(
                format!(
                    "'--{}', '{}', {}, '{}')",
                    data, data, "[CompletionResultType]::ParameterName", tooltip
                )
                .as_str(),
            );
        }
    }

    for flag in p.flags() {
        if let Some(data) = flag.s.short {
            let tooltip = get_tooltip(flag.b.help, data);
            completions.push_str(&preamble);
            completions.push_str(
                format!(
                    "'-{}', '{}', {}, '{}')",
                    data, data, "[CompletionResultType]::ParameterName", tooltip
                )
                .as_str(),
            );
        }
        if let Some(data) = flag.s.long {
            let tooltip = get_tooltip(flag.b.help, data);
            completions.push_str(&preamble);
            completions.push_str(
                format!(
                    "'--{}', '{}', {}, '{}')",
                    data, data, "[CompletionResultType]::ParameterName", tooltip
                )
                .as_str(),
            );
        }
    }

    for subcommand in &p.subcommands {
        let data = &subcommand.p.meta.name;
        let tooltip = get_tooltip(subcommand.p.meta.about, data);
        completions.push_str(&preamble);
        completions.push_str(
            format!(
                "'{}', '{}', {}, '{}')",
                data, data, "[CompletionResultType]::ParameterValue", tooltip
            )
            .as_str(),
        );
    }

    let mut subcommands_cases = format!(
        r"
        '{}' {{{}
            break
        }}",
        &command_name, completions
    );

    for subcommand in &p.subcommands {
        let subcommand_subcommands_cases = generate_inner(&subcommand.p, &command_name, names);
        subcommands_cases.push_str(&subcommand_subcommands_cases);
    }

    subcommands_cases
}