gitignore_template_generator/parser/
impls.rs

1use std::{ffi::OsString, process::exit};
2
3use clap::{ArgMatches, Command};
4
5use super::{Args, ArgsParser, command::build_clap_args};
6use crate::{ExitKind, ProgramExit, constant};
7
8/// Default implementation of args parser that parses CLI args using
9/// [`clap`].
10pub struct ClapArgsParser {
11    cli_parser: Command,
12}
13
14#[allow(clippy::new_without_default)]
15impl ClapArgsParser {
16    pub fn new() -> Self {
17        Self {
18            cli_parser: Command::new(env!("CARGO_PKG_NAME"))
19                .version(env!("CARGO_PKG_VERSION"))
20                .author(env!("CARGO_PKG_AUTHORS"))
21                .about(constant::parser_infos::ABOUT)
22                .help_template(include_str!("../../assets/help_template.txt"))
23                .disable_help_flag(true)
24                .disable_version_flag(true)
25                .args(build_clap_args()),
26        }
27    }
28
29    fn parse_global_options(&self, args: &Args) -> Option<ProgramExit> {
30        if args.show_help {
31            let rendered_help = self.cli_parser.clone().render_help();
32            Some(ProgramExit {
33                message: rendered_help.to_string().trim_end().to_string(),
34                exit_status: constant::exit_status::SUCCESS,
35                styled_message: Some(
36                    rendered_help.ansi().to_string().trim_end().to_string(),
37                ),
38                kind: ExitKind::HelpInfos,
39            })
40        } else if args.show_version {
41            let message = match self.cli_parser.get_version() {
42                Some(version) => {
43                    format!("{} {version}", env!("CARGO_PKG_NAME"))
44                }
45                None => constant::error_messages::VERSION_INFOS_NOT_AVAILABLE
46                    .to_string(),
47            };
48
49            Some(ProgramExit {
50                message,
51                exit_status: constant::exit_status::SUCCESS,
52                styled_message: None,
53                kind: ExitKind::VersionInfos,
54            })
55        } else if args.show_author {
56            let message = String::from(match self.cli_parser.get_author() {
57                Some(author) => author,
58                None => constant::error_messages::AUTHOR_INFOS_NOT_AVAILABLE,
59            });
60
61            Some(ProgramExit {
62                message,
63                exit_status: constant::exit_status::SUCCESS,
64                styled_message: None,
65                kind: ExitKind::AuthorInfos,
66            })
67        } else {
68            None
69        }
70    }
71
72    fn map_arg_matches_to_struct(arg_matches: &ArgMatches) -> Args {
73        Args {
74            template_names: arg_matches
75                .get_many::<String>("TEMPLATE_NAMES")
76                .map(|vals| vals.cloned().collect())
77                .unwrap_or_default(),
78
79            server_url: arg_matches
80                .get_one::<String>("SERVER_URL")
81                .unwrap()
82                .to_string(),
83
84            generator_uri: arg_matches
85                .get_one::<String>("GENERATOR_URI")
86                .unwrap()
87                .to_string(),
88
89            lister_uri: arg_matches
90                .get_one::<String>("LISTER_URI")
91                .unwrap()
92                .to_string(),
93
94            check_template_names: arg_matches.get_flag("CHECK"),
95            show_help: arg_matches.get_flag("HELP"),
96            show_version: arg_matches.get_flag("VERSION"),
97            show_author: arg_matches.get_flag("AUTHOR"),
98            show_list: arg_matches.get_flag("LIST"),
99        }
100    }
101
102    fn print_error_message(error: &ProgramExit, message: &str) {
103        match error.kind {
104            ExitKind::VersionInfos
105            | ExitKind::HelpInfos
106            | ExitKind::AuthorInfos => println!("{message}"),
107            ExitKind::Error => eprintln!("{message}"),
108        }
109    }
110}
111
112impl ArgsParser for ClapArgsParser {
113    /// Parses given cli args and perform basic error handling.
114    ///
115    /// * If the underlying [`ProgramExit`] contains a
116    ///     [`ProgramExit::styled_message`], it will be printed instead of
117    ///     [`ProgramExit::message`].
118    /// * Will exit using [`ProgramExit::exit_status`] if any
119    ///     [`ProgramExit`] received.
120    /// * Will print to stderr on error, to stdout on early exit (i.e. version,
121    ///     author, help options)
122    ///
123    /// See [`ArgsParser::parse`] for more infos.
124    fn parse(&self, args: impl IntoIterator<Item = OsString>) -> Args {
125        match self.try_parse(args) {
126            Ok(parsed_args) => parsed_args,
127            Err(error) => {
128                if let Some(value) = &error.styled_message {
129                    Self::print_error_message(&error, value);
130                } else {
131                    Self::print_error_message(&error, &error.message);
132                }
133
134                exit(error.exit_status);
135            }
136        }
137    }
138
139    fn try_parse(
140        &self,
141        args: impl IntoIterator<Item = OsString>,
142    ) -> Result<Args, ProgramExit> {
143        match self.cli_parser.clone().try_get_matches_from(args) {
144            Ok(parsing_result) => {
145                let parsed_args =
146                    Self::map_arg_matches_to_struct(&parsing_result);
147                match self.parse_global_options(&parsed_args) {
148                    Some(error) => Err(error),
149                    None => Ok(parsed_args),
150                }
151            }
152            Err(error) => Err(ProgramExit {
153                message: format!(
154                    "{}\nFor more information, try '--help'.",
155                    error.render()
156                ),
157                exit_status: error.exit_code(),
158                styled_message: Some(format!(
159                    "{}\nFor more information, try '\u{1b}[1m--help\u{1b}[0m'.",
160                    error.render().ansi()
161                )),
162                kind: ExitKind::Error,
163            }),
164        }
165    }
166}