// Copyright (c) 2020  Teddy Wing
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.


static FLAGS: [&'static str; 59] = [
    "-p",
    "--no-stat",
    "-p",
    "-u",
    "--patch",
    "-s",
    "--no-patch",
    "--raw",
    "--patch-with-raw",
    "-t",
    "--indent-heuristic",
    "--no-indent-heuristic",
    "--minimal",
    "--patience",
    "--histogram",
    "--compact-summary",
    "--numstat",
    "--shortstat",
    "--cumulative",
    "--summary",
    "--patch-with-stat",
    "-z",
    "--name-only",
    "--name-status",
    "--no-color",
    "--no-color-moved",
    "--no-color-moved-ws",
    "--no-renames",
    "--rename-empty",
    "--no-rename-empty",
    "--check",
    "--full-index",
    "--binary",
    "--find-copies-harder",
    "-D",
    "--irreversible-delete",
    "--pickaxe-all",
    "--pickaxe-regex",
    "-R",
    "--no-relative",
    "-a",
    "--text",
    "--ignore-cr-at-eol",
    "--ignore-space-at-eol",
    "-b",
    "--ignore-space-change",
    "-w",
    "--ignore-all-space",
    "--ignore-blank-lines",
    "-W",
    "--function-context",
    "--exit-code",
    "--quiet",
    "--ext-diff",
    "--no-ext-diff",
    "--textconv",
    "--no-textconv",
    "--no-prefix",
    "--ita-invisible-in-index",
];

// static OPTIONS: [&'static str; 21] = [
//     "-U<n>",
//     "--unified=<n>",
//     "--output=<file>",
//     "--output-indicator-new=<char>",
//     "--output-indicator-old=<char>",
//     "--output-indicator-context=<char>",
//     "--anchored=<text>",
//     "--diff-algorithm={patience|minimal|histogram|myers}",
//     "--stat[=<width>[,<name-width>[,<count>]]]",
//     "-X[<param1,param2,...>]",
//     "--dirstat[=<param1,param2,...>]",
//     "--dirstat-by-file[=<param1,param2>...]",
//     "--submodule[=<format>]",
//     "--color[=<when>]",
//     "--color-moved[=<mode>]",
//     "--color-moved-ws=<modes>",
//     "--word-diff[=<mode>]",
//     "--word-diff-regex=<regex>",
//     "--color-words[=<regex>]",
//     "--ws-error-highlight=<kind>",
//     "--abbrev[=<n>]",
//     "-B[<n>][/<m>]",
//     "--break-rewrites[=[<n>][/<m>]]",
//     "-M[<n>]",
//     "--find-renames[=<n>]",
//     "-C[<n>]",
//     "--find-copies[=<n>]",
//     "-l<num>",
//     "--diff-filter=[(A|C|D|M|R|T|U|X|B)...[*]]",
//     "-S<string>",
//     "-G<regex>",
//     "--find-object=<object-id>",
//     "-O<orderfile>",
//     "--relative[=<path>]",
//     "--inter-hunk-context=<lines>",
//     "--ignore-submodules[=<when>]",
//     "--src-prefix=<prefix>",
//     "--dst-prefix=<prefix>",
//     "--line-prefix=<prefix>",
// ];

static ARG_OPTIONS: [&'static str; 20] = [
    "-U",
    "--unified",
    "--output",
    "--output-indicator-new",
    "--output-indicator-old",
    "--output-indicator-context",
    "--anchored",
    "--diff-algorithm",
    "--color-moved-ws",
    "--word-diff-regex",
    "--ws-error-highlight",
    "-l",
    "-S",
    "-G",
    "--find-object",
    "-O",
    "--inter-hunk-context",
    "--src-prefix",
    "--dst-prefix",
    "--line-prefix",
];

static OPT_OPTIONS: [&'static str; 19] = [
    "--stat",
    "-X",
    "--dirstat",
    "--dirstat-by-file",
    "--submodule",
    "--color",
    "--color-moved",
    "--word-diff",
    "--color-words",
    "--abbrev",
    "-B",
    "--break-rewrites",
    "-M",
    "--find-renames",
    "-C",
    "--find-copies",
    "--diff-filter",
    "--relative",
    "--ignore-submodules",
];


// pub fn parse(args: &[String]) -> &[String] {
pub fn parse(args: &[String]) -> (Vec<&String>, Vec<&String>) {
    let mut program_args = Vec::new();
    let mut found_args = Vec::new();
    let mut add_next_arg = false;

    'args: for arg in args {
        let find_arg_prefix = arg.find('-');

        // TODO: Ignore suggestion args
        if add_next_arg
            && (
                find_arg_prefix.is_none()
                || find_arg_prefix != Some(0)
            )
        {
            found_args.push(arg);

            add_next_arg = false;

            continue;
        }

        for flag in FLAGS.iter() {
            if arg.starts_with(flag) {
                found_args.push(arg);

                continue 'args;
            }
        }

        // TODO: check for "=" and get next arg
        // '='
        // if no equals, then add next arg
        // Turns out values are always specified with '='
        for option in &ARG_OPTIONS {
            if arg.starts_with(option) {
                found_args.push(arg);

                // if arg doesn't have an = after it
                // if i < arg.len() {
                // let char_after_option = arg.get(option.len());
                // if char_after_option.is_some()
                //         && char_after_option.unwrap() == '=' {

                let (_option, rest) = arg.split_at(option.len());

                dbg!(arg);
                dbg!(arg.len());
                dbg!(option);
                dbg!(option.len());
                dbg!(rest.find('=').is_none());
                // if arg.len() > option.len()
                //         && rest.find('=').is_none() {
                // if rest.find('=').is_none() {
                //     add_next_arg = true;
                // }

                continue 'args;
            }
        }

        // check '='
        // If no equals, add next arg if it doesn't begin with '-'
        // OptOptions are always followed by '=' when specifying values
        for option in &OPT_OPTIONS {
            if arg.starts_with(option) {
                found_args.push(arg);

                // let (_option, rest) = arg.split_at(option.len());
                //
                // if rest.find('=').is_none() {
                //     add_next_arg = true;
                // }

                continue 'args;
            }
        }

        // TODO: Otherwise, add to normal arguments list
        program_args.push(arg)
    }

    (program_args, found_args)
}


#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn parse_extracts_diff_options() {
        let args = vec![
            "--github-token".to_owned(),
            "MY_TOKEN".to_owned(),
            "--diff-filter=A".to_owned(),
            "-D".to_owned(),
            "--color=always".to_owned(),
            "-U5".to_owned(),
            "--patience".to_owned(),
            "--ws-error-highlight=old,new".to_owned(),
            "--no-rename-empty".to_owned(),
            "--stat=50".to_owned(),
            "-M90%".to_owned(),
            "--relative".to_owned(),
        ];

        let (_, diff_opts) = parse(&args);

        assert_eq!(diff_opts, vec![
            "--diff-filter=A",
            "-D",
            "--color=always",
            "-U5",
            "--patience",
            "--ws-error-highlight=old,new",
            "--no-rename-empty",
            "--stat=50",
            "-M90%",
            "--relative",
        ]);
    }

    #[test]
    fn parse_does_not_consume_suggestion_args() {
        let args = vec![
            "--github-token".to_owned(),
            "MY_TOKEN".to_owned(),
            "--word-diff".to_owned(),
            "459692838".to_owned(),
            "https://github.com/teddywing/git-suggestion/pull/1#discussion_r459691747".to_owned(),
        ];

        let (options, diff_opts) = parse(&args);

        assert_eq!(diff_opts, vec!["--word-diff"]);
        assert_eq!(options, vec![
            "--github-token",
            "MY_TOKEN",
            "459692838",
            "https://github.com/teddywing/git-suggestion/pull/1#discussion_r459691747",
        ]);
    }
}

// -p
// --no-stat
// -p
// -u
// --patch
// -s
// --no-patch
// -U<n>
// --unified=<n>
// --output=<file>
// --output-indicator-new=<char>
// --output-indicator-old=<char>
// --output-indicator-context=<char>
// --raw
// --patch-with-raw
// -t
// --indent-heuristic
// --no-indent-heuristic
// --minimal
// --patience
// --histogram
// --anchored=<text>
// --diff-algorithm={patience|minimal|histogram|myers}
// --stat[=<width>[,<name-width>[,<count>]]]
// --compact-summary
// --numstat
// --shortstat
// -X[<param1,param2,...>]
// --dirstat[=<param1,param2,...>]
// --cumulative
// --dirstat-by-file[=<param1,param2>...]
// --summary
// --patch-with-stat
// -z
// --name-only
// --name-status
// --submodule[=<format>]
// --color[=<when>]
// --no-color
// --color-moved[=<mode>]
// --no-color-moved
// --color-moved-ws=<modes>
// --no-color-moved-ws
// --word-diff[=<mode>]
// --word-diff-regex=<regex>
// --color-words[=<regex>]
// --no-renames
// --[no-]rename-empty
// --check
// --ws-error-highlight=<kind>
// --full-index
// --binary
// --abbrev[=<n>]
// -B[<n>][/<m>]
// --break-rewrites[=[<n>][/<m>]]
// -M[<n>]
// --find-renames[=<n>]
// -C[<n>]
// --find-copies[=<n>]
// --find-copies-harder
// -D
// --irreversible-delete
// -l<num>
// --diff-filter=[(A|C|D|M|R|T|U|X|B)...[*]]
// -S<string>
// -G<regex>
// -S"frotz\(nitfol" --pickaxe-regex` will not (because the number of
// --find-object=<object-id>
// --pickaxe-all
// --pickaxe-regex
// -O<orderfile>
// -R
// --relative[=<path>]
// --no-relative
// -a
// --text
// --ignore-cr-at-eol
// --ignore-space-at-eol
// -b
// --ignore-space-change
// -w
// --ignore-all-space
// --ignore-blank-lines
// --inter-hunk-context=<lines>
// -W
// --function-context
// --exit-code
// --quiet
// --ext-diff
// --no-ext-diff
// --textconv
// --no-textconv
// --ignore-submodules[=<when>]
// --src-prefix=<prefix>
// --dst-prefix=<prefix>
// --no-prefix
// --line-prefix=<prefix>
// --ita-invisible-in-index