// This file is part of the uutils coreutils package.
//
// For the full copyright and license information, please view the LICENSE
// file that was distributed with this source code.
// spell-checker:ignore (ToDO) Sdivide

use jiff::{Timestamp, ToSpan};
use regex::Regex;
use std::fs::metadata;
use uutests::new_ucmd;
use uutests::util::UCommand;

const DATE_TIME_FORMAT_DEFAULT: &str = "%Y-%m-%d %H:%M";

fn file_last_modified_time_format(ucmd: &UCommand, path: &str, format: &str) -> String {
    let tmp_dir_path = ucmd.get_full_fixture_path(path);
    metadata(tmp_dir_path)
        .and_then(|meta| meta.modified())
        .map(|mtime| {
            let dt: Timestamp = mtime.try_into().unwrap();
            dt.strftime(format).to_string()
        })
        .unwrap_or_default()
}

fn file_last_modified_time(ucmd: &UCommand, path: &str) -> String {
    file_last_modified_time_format(ucmd, path, DATE_TIME_FORMAT_DEFAULT)
}

fn all_minutes(from: Timestamp, to: Timestamp) -> Vec<String> {
    let to = to + 1.minute();
    let mut vec = vec![];
    let mut current = from;
    while current < to {
        vec.push(current.strftime(DATE_TIME_FORMAT_DEFAULT).to_string());
        current += 1.minute();
    }
    vec
}

fn valid_last_modified_template_vars(from: Timestamp) -> Vec<Vec<(String, String)>> {
    all_minutes(from, Timestamp::now())
        .into_iter()
        .map(|time| vec![("{last_modified_time}".to_string(), time)])
        .collect()
}

#[test]
fn test_invalid_flag() {
    new_ucmd!()
        .arg("--invalid-argument")
        .fails_with_code(1)
        .no_stdout();
}

#[test]
fn test_without_any_options() {
    let test_file_path = "test_one_page.log";
    let expected_test_file_path = "test_one_page.log.expected";
    let mut scenario = new_ucmd!();
    let value = file_last_modified_time(&scenario, test_file_path);
    scenario
        .args(&[test_file_path])
        .succeeds()
        .stdout_is_templated_fixture(expected_test_file_path, &[("{last_modified_time}", &value)]);
}

#[test]
fn test_with_numbering_option_with_number_width() {
    let test_file_path = "test_num_page.log";
    let expected_test_file_path = "test_num_page_2.log.expected";
    let mut scenario = new_ucmd!();
    let value = file_last_modified_time(&scenario, test_file_path);
    scenario
        .args(&["-n", "2", test_file_path])
        .succeeds()
        .stdout_is_templated_fixture(expected_test_file_path, &[("{last_modified_time}", &value)]);
}

#[test]
fn test_with_long_header_option() {
    let whitespace = " ".repeat(21);
    let blank_lines = "\n".repeat(61);
    let datetime_pattern = r"\d\d\d\d-\d\d-\d\d \d\d:\d\d";
    let pattern =
        format!("\n\n{datetime_pattern}{whitespace}new file{whitespace}Page 1\n\n\na{blank_lines}");
    let regex = Regex::new(&pattern).unwrap();
    new_ucmd!()
        .args(&["-h", "new file"])
        .pipe_in("a")
        .succeeds()
        .stdout_matches(&regex);
    new_ucmd!()
        .args(&["--header=new file"])
        .pipe_in("a")
        .succeeds()
        .stdout_matches(&regex);
}

#[test]
fn test_with_double_space_option() {
    let test_file_path = "test_one_page.log";
    let expected_test_file_path = "test_one_page_double_line.log.expected";
    for arg in ["-d", "--double-space"] {
        let mut scenario = new_ucmd!();
        let value = file_last_modified_time(&scenario, test_file_path);
        scenario
            .args(&[arg, test_file_path])
            .succeeds()
            .stdout_is_templated_fixture(
                expected_test_file_path,
                &[("{last_modified_time}", &value)],
            );
    }
}

#[test]
fn test_with_first_line_number_option() {
    let test_file_path = "test_one_page.log";
    let expected_test_file_path = "test_one_page_first_line.log.expected";
    let mut scenario = new_ucmd!();
    let value = file_last_modified_time(&scenario, test_file_path);
    scenario
        .args(&["-N", "5", "-n", test_file_path])
        .succeeds()
        .stdout_is_templated_fixture(expected_test_file_path, &[("{last_modified_time}", &value)]);
}

#[test]
fn test_with_first_line_number_long_option() {
    let test_file_path = "test_one_page.log";
    let expected_test_file_path = "test_one_page_first_line.log.expected";
    let mut scenario = new_ucmd!();
    let value = file_last_modified_time(&scenario, test_file_path);
    scenario
        .args(&["--first-line-number=5", "-n", test_file_path])
        .succeeds()
        .stdout_is_templated_fixture(expected_test_file_path, &[("{last_modified_time}", &value)]);
}

#[test]
fn test_with_number_option_with_custom_separator_char() {
    let test_file_path = "test_num_page.log";
    let expected_test_file_path = "test_num_page_char.log.expected";
    let mut scenario = new_ucmd!();
    let value = file_last_modified_time(&scenario, test_file_path);
    scenario
        .args(&["-nc", test_file_path])
        .succeeds()
        .stdout_is_templated_fixture(expected_test_file_path, &[("{last_modified_time}", &value)]);
}

#[test]
fn test_with_number_option_with_custom_separator_char_and_width() {
    let test_file_path = "test_num_page.log";
    let expected_test_file_path = "test_num_page_char_one.log.expected";
    let mut scenario = new_ucmd!();
    let value = file_last_modified_time(&scenario, test_file_path);
    scenario
        .args(&["-nc1", test_file_path])
        .succeeds()
        .stdout_is_templated_fixture(expected_test_file_path, &[("{last_modified_time}", &value)]);
}

#[test]
fn test_with_valid_page_ranges() {
    let test_file_path = "test_num_page.log";
    let mut scenario = new_ucmd!();
    scenario
        .args(&["--pages=20:5", test_file_path])
        .fails()
        .stderr_is("pr: invalid --pages argument '20:5'\n")
        .stdout_is("");
    new_ucmd!()
        .args(&["--pages=1:5", test_file_path])
        .succeeds();
    new_ucmd!().args(&["--pages=1", test_file_path]).succeeds();
    new_ucmd!()
        .args(&["--pages=-1:5", test_file_path])
        .fails()
        .stderr_is("pr: invalid --pages argument '-1:5'\n")
        .stdout_is("");
    new_ucmd!()
        .args(&["--pages=1:-5", test_file_path])
        .fails()
        .stderr_is("pr: invalid --pages argument '1:-5'\n")
        .stdout_is("");
    new_ucmd!()
        .args(&["--pages=5:1", test_file_path])
        .fails()
        .stderr_is("pr: invalid --pages argument '5:1'\n")
        .stdout_is("");
}

#[test]
fn test_with_page_range() {
    let test_file_path = "test.log";
    let expected_test_file_path = "test_page_range_1.log.expected";
    let expected_test_file_path1 = "test_page_range_2.log.expected";
    for arg in ["--pages=15", "+15"] {
        let mut scenario = new_ucmd!();
        let value = file_last_modified_time(&scenario, test_file_path);
        scenario
            .args(&[arg, test_file_path])
            .succeeds()
            .stdout_is_templated_fixture(
                expected_test_file_path,
                &[("{last_modified_time}", &value)],
            );
    }
    for arg in ["--pages=15:17", "+15:17"] {
        let mut scenario = new_ucmd!();
        let value = file_last_modified_time(&scenario, test_file_path);
        scenario
            .args(&[arg, test_file_path])
            .succeeds()
            .stdout_is_templated_fixture(
                expected_test_file_path1,
                &[("{last_modified_time}", &value)],
            );
    }
}

#[test]
fn test_with_no_header_trailer_option() {
    let test_file_path = "test_one_page.log";
    let expected_test_file_path = "test_one_page_no_ht.log.expected";
    let mut scenario = new_ucmd!();
    let value = file_last_modified_time(&scenario, test_file_path);
    scenario
        .args(&["-t", test_file_path])
        .succeeds()
        .stdout_is_templated_fixture(expected_test_file_path, &[("{last_modified_time}", &value)]);
}

#[test]
fn test_with_page_length_option() {
    let test_file_path = "test.log";
    for (arg, expected) in [
        ("100", "test_page_length.log.expected"),
        ("5", "test_page_length1.log.expected"),
    ] {
        let mut scenario = new_ucmd!();
        let value = file_last_modified_time(&scenario, test_file_path);
        scenario
            .args(&["--pages=2:3", "-l", arg, "-n", test_file_path])
            .succeeds()
            .stdout_is_templated_fixture(expected, &[("{last_modified_time}", &value)]);
    }
}

#[test]
fn test_with_suppress_error_option() {
    let test_file_path = "test_num_page.log";
    let mut scenario = new_ucmd!();
    scenario
        .args(&["--pages=20:5", "-r", test_file_path])
        .fails()
        .stderr_is("")
        .stdout_is("");
}

#[test]
fn test_with_stdin() {
    let expected_file_path = "stdin.log.expected";
    let mut scenario = new_ucmd!();
    let start = Timestamp::now();
    scenario
        .pipe_in_fixture("stdin.log")
        .args(&["--pages=1:2", "-n", "-"])
        .succeeds()
        .stdout_is_templated_fixture_any(
            expected_file_path,
            &valid_last_modified_template_vars(start),
        );
}

#[test]
fn test_with_column() {
    let test_file_path = "column.log";
    let expected_test_file_path = "column.log.expected";
    for arg in ["-3", "--column=3"] {
        let mut scenario = new_ucmd!();
        let value = file_last_modified_time(&scenario, test_file_path);
        scenario
            .args(&["--pages=3:5", arg, "-n", test_file_path])
            .succeeds()
            .stdout_is_templated_fixture(
                expected_test_file_path,
                &[("{last_modified_time}", &value)],
            );
    }
}

#[test]
fn test_with_column_across_option() {
    let test_file_path = "column.log";
    let expected_test_file_path = "column_across.log.expected";
    let mut scenario = new_ucmd!();
    let value = file_last_modified_time(&scenario, test_file_path);
    scenario
        .args(&["--pages=3:5", "--column=3", "-a", "-n", test_file_path])
        .succeeds()
        .stdout_is_templated_fixture(expected_test_file_path, &[("{last_modified_time}", &value)]);
}

#[test]
fn test_with_column_across_option_and_column_separator() {
    let test_file_path = "column.log";
    for (arg, expected) in [
        ("-s|", "column_across_sep.log.expected"),
        ("-Sdivide", "column_across_sep1.log.expected"),
    ] {
        let mut scenario = new_ucmd!();
        let value = file_last_modified_time(&scenario, test_file_path);
        scenario
            .args(&["--pages=3:5", "--column=3", arg, "-a", "-n", test_file_path])
            .succeeds()
            .stdout_is_templated_fixture(expected, &[("{last_modified_time}", &value)]);
    }
}

#[test]
fn test_with_mpr() {
    let test_file_path = "column.log";
    let test_file_path1 = "hosts.log";
    let expected_test_file_path = "mpr.log.expected";
    let expected_test_file_path1 = "mpr1.log.expected";
    let expected_test_file_path2 = "mpr2.log.expected";
    let start = Timestamp::now();
    new_ucmd!()
        .args(&["--pages=1:2", "-m", "-n", test_file_path, test_file_path1])
        .succeeds()
        .stdout_is_templated_fixture_any(
            expected_test_file_path,
            &valid_last_modified_template_vars(start),
        );

    let start = Timestamp::now();
    new_ucmd!()
        .args(&["--pages=2:4", "-m", "-n", test_file_path, test_file_path1])
        .succeeds()
        .stdout_is_templated_fixture_any(
            expected_test_file_path1,
            &valid_last_modified_template_vars(start),
        );

    let start = Timestamp::now();
    new_ucmd!()
        .args(&[
            "--pages=1:2",
            "-l",
            "100",
            "-n",
            "-m",
            test_file_path,
            test_file_path1,
            test_file_path,
        ])
        .succeeds()
        .stdout_is_templated_fixture_any(
            expected_test_file_path2,
            &valid_last_modified_template_vars(start),
        );
}

#[test]
fn test_with_mpr_and_column_options() {
    let test_file_path = "column.log";
    new_ucmd!()
        .args(&["--column=2", "-m", "-n", test_file_path])
        .fails()
        .stderr_is("pr: cannot specify number of columns when printing in parallel\n")
        .stdout_is("");

    new_ucmd!()
        .args(&["-a", "-m", "-n", test_file_path])
        .fails()
        .stderr_is("pr: cannot specify both printing across and printing in parallel\n")
        .stdout_is("");
}

#[test]
fn test_with_offset_space_option() {
    let test_file_path = "column.log";
    let expected_test_file_path = "column_spaces_across.log.expected";
    let mut scenario = new_ucmd!();
    let value = file_last_modified_time(&scenario, test_file_path);
    scenario
        .args(&[
            "-o",
            "5",
            "--pages=3:5",
            "--column=3",
            "-a",
            "-n",
            test_file_path,
        ])
        .succeeds()
        .stdout_is_templated_fixture(expected_test_file_path, &[("{last_modified_time}", &value)]);
}

#[test]
fn test_with_date_format() {
    let whitespace = " ".repeat(50);
    let blank_lines = "\n".repeat(61);
    let datetime_pattern = r"\d{4}__\d{10}";
    let pattern = format!("\n\n{datetime_pattern}{whitespace}Page 1\n\n\na{blank_lines}");
    let regex = Regex::new(&pattern).unwrap();
    new_ucmd!()
        .args(&["-D", "%Y__%s"])
        .pipe_in("a")
        .succeeds()
        .stdout_matches(&regex);

    // "Format" doesn't need to contain any replaceable token.
    let whitespace = " ".repeat(60);
    let blank_lines = "\n".repeat(61);
    new_ucmd!()
        .args(&["-D", "Hello!"])
        .pipe_in("a")
        .succeeds()
        .stdout_only(format!("\n\nHello!{whitespace}Page 1\n\n\na{blank_lines}"));

    // Long option also works
    new_ucmd!()
        .args(&["--date-format=Hello!"])
        .pipe_in("a")
        .succeeds()
        .stdout_only(format!("\n\nHello!{whitespace}Page 1\n\n\na{blank_lines}"));

    // Option takes precedence over environment variables
    new_ucmd!()
        .env("POSIXLY_CORRECT", "1")
        .env("LC_TIME", "POSIX")
        .args(&["--date-format=Hello!"])
        .pipe_in("a")
        .succeeds()
        .stdout_only(format!("\n\nHello!{whitespace}Page 1\n\n\na{blank_lines}"));
}

#[test]
fn test_with_date_format_env() {
    // POSIXLY_CORRECT + LC_ALL/TIME=POSIX uses "%b %e %H:%M %Y" date format
    let whitespace = " ".repeat(49);
    let blank_lines = "\n".repeat(61);
    let datetime_pattern = r"[A-Z][a-z][a-z] [ \d]\d \d\d:\d\d \d{4}";
    let pattern = format!("\n\n{datetime_pattern}{whitespace}Page 1\n\n\na{blank_lines}");
    let regex = Regex::new(&pattern).unwrap();
    new_ucmd!()
        .env("POSIXLY_CORRECT", "1")
        .env("LC_ALL", "POSIX")
        .pipe_in("a")
        .succeeds()
        .stdout_matches(&regex);
    new_ucmd!()
        .env("POSIXLY_CORRECT", "1")
        .env("LC_TIME", "POSIX")
        .pipe_in("a")
        .succeeds()
        .stdout_matches(&regex);

    // But not if POSIXLY_CORRECT/LC_ALL is something else.
    let whitespace = " ".repeat(50);
    let datetime_pattern = r"\d\d\d\d-\d\d-\d\d \d\d:\d\d";
    let pattern = format!("\n\n{datetime_pattern}{whitespace}Page 1\n\n\na{blank_lines}");
    let regex = Regex::new(&pattern).unwrap();
    new_ucmd!()
        .env("LC_TIME", "POSIX")
        .pipe_in("a")
        .succeeds()
        .stdout_matches(&regex);
    new_ucmd!()
        .env("POSIXLY_CORRECT", "1")
        .env("LC_TIME", "C")
        .pipe_in("a")
        .succeeds()
        .stdout_matches(&regex);
}

#[test]
fn test_with_join_lines_option() {
    let test_file_1 = "hosts.log";
    let test_file_2 = "test.log";
    let expected_file_path = "joined.log.expected";
    let mut scenario = new_ucmd!();
    let start = Timestamp::now();
    scenario
        .args(&["+1:2", "-J", "-m", test_file_1, test_file_2])
        .succeeds()
        .stdout_is_templated_fixture_any(
            expected_file_path,
            &valid_last_modified_template_vars(start),
        );
}

#[test]
fn test_value_for_number_lines() {
    // *5 is of the form [SEP[NUMBER]] so is accepted and succeeds
    new_ucmd!().args(&["-n", "*5", "test.log"]).succeeds();

    // a is of the form [SEP[NUMBER]] so is accepted and succeeds
    new_ucmd!().args(&["-n", "a", "test.log"]).succeeds();

    // foo5.txt is of not the form [SEP[NUMBER]] so is not used as value.
    // Therefore, pr tries to access the file, which does not exist.
    new_ucmd!().args(&["-n", "foo5.txt", "test.log"]).fails();
}

#[test]
fn test_header_formatting_with_custom_date_format() {
    // This test verifies that the header is properly formatted with:
    // - Date/time on the left
    // - Filename centered
    // - "Page X" on the right
    // This matches GNU pr behavior for the time-style test

    let test_file_path = "test_one_page.log";

    // Set a specific date format like in the GNU test
    let output = new_ucmd!()
        .args(&["-D", "+%Y-%m-%d %H:%M:%S %z (%Z)", test_file_path])
        .succeeds()
        .stdout_move_str();

    // Extract the header line (3rd line of output)
    let lines: Vec<&str> = output.lines().collect();
    assert!(
        lines.len() >= 5,
        "Output should have at least 5 lines for header"
    );

    let header_line = lines[2];

    // The header should be 72 characters wide (default page width)
    assert_eq!(header_line.chars().count(), 72);

    // Check that it contains the expected parts
    assert!(header_line.contains(test_file_path));
    assert!(header_line.contains("Page 1"));

    // Verify the filename is roughly centered
    let filename_pos = header_line.find(test_file_path).unwrap();
    let page_pos = header_line.find("Page 1").unwrap();

    // Filename should be somewhere in the middle third of the line
    assert!(filename_pos > 24 && filename_pos < 48);

    // Page should be right-aligned (near the end)
    assert!(page_pos >= 60);
}

#[test]
fn test_help() {
    new_ucmd!().arg("--help").succeeds();
}

#[test]
fn test_version() {
    new_ucmd!().arg("--version").succeeds();
}

#[cfg(unix)]
#[test]
fn test_pr_char_device_dev_null() {
    new_ucmd!().arg("/dev/null").succeeds();
}

#[test]
fn test_b_flag_backwards_compat() {
    // -b is a no-op for backwards compatibility (column-down is now the default)
    new_ucmd!().args(&["-b", "-t"]).pipe_in("a\nb\n").succeeds();
}

#[test]
fn test_page_header_width() {
    let whitespace = " ".repeat(50);
    let blank_lines = "\n".repeat(61);
    let datetime_pattern = r"\d\d\d\d-\d\d-\d\d \d\d:\d\d";
    let pattern = format!("\n\n{datetime_pattern}{whitespace}Page 1\n\n\na{blank_lines}");
    let regex = Regex::new(&pattern).unwrap();
    new_ucmd!().pipe_in("a").succeeds().stdout_matches(&regex);
}

#[test]
fn test_separator_options_default_values() {
    // -s and -S without arguments should use default values (TAB and space)
    // TODO: verify output matches GNU pr behavior
    new_ucmd!()
        .args(&["-t", "-2", "-s"])
        .pipe_in("a\nb\n")
        .succeeds();
    new_ucmd!()
        .args(&["-t", "-2", "-S"])
        .pipe_in("a\nb\n")
        .succeeds();
}

#[test]
fn test_omit_pagination_option() {
    // -T/--omit-pagination omits headers/trailers and eliminates form feeds
    // TODO: verify output matches GNU pr behavior (form feed elimination)
    new_ucmd!().args(&["-T"]).pipe_in("a\nb\n").succeeds();
    new_ucmd!()
        .args(&["--omit-pagination"])
        .pipe_in("a\nb\n")
        .succeeds();
}

#[test]
fn test_form_feed_newlines() {
    // Here we define the expected output.
    //
    // Each page should have the same number of blank lines before the
    // form-feed character.
    let whitespace = " ".repeat(50);
    let datetime_pattern = r"\d\d\d\d-\d\d-\d\d \d\d:\d\d";
    let page1 = format!("\n\n{datetime_pattern}{whitespace}Page 1\n\n\n\n\x0c");
    let page2 = format!("\n\n{datetime_pattern}{whitespace}Page 2\n\n\n\n\x0c");
    let pattern = format!("{page1}{page2}");
    let regex = Regex::new(&pattern).unwrap();

    // Command line: `printf "\f\f" | pr -f`.
    //
    // Escape code `\x0c` in a Rust string literal is the ASCII escape
    // code `\f` for the "form feed" character (which appears like
    // `^L` in the terminal).
    new_ucmd!()
        .arg("-f")
        .pipe_in("\x0c\x0c")
        .succeeds()
        .stdout_matches(&regex);
}

#[test]
fn test_new_line_followed_by_form_feed() {
    // Here we define the expected output.
    let whitespace = " ".repeat(50);
    let datetime_pattern = r"\d\d\d\d-\d\d-\d\d \d\d:\d\d";
    let pattern = format!("\n\n{datetime_pattern}{whitespace}Page 1\n\n\nabc\n\x0c");
    let regex = Regex::new(&pattern).unwrap();

    // Command line: `printf "abc\n\f" | pr -f`.
    new_ucmd!()
        .arg("-f")
        .pipe_in("abc\n\x0c")
        .succeeds()
        .stdout_matches(&regex);
}

#[test]
fn test_form_feed_followed_by_new_line() {
    // Here we define the expected output.
    let whitespace = " ".repeat(50);
    let datetime_pattern = r"\d\d\d\d-\d\d-\d\d \d\d:\d\d";
    let blank_lines_61 = "\n".repeat(61);
    let blank_lines_60 = "\n".repeat(60);
    let page1 = format!("\n\n{datetime_pattern}{whitespace}Page 1\n\n\n{blank_lines_61}");
    let page2 = format!("\n\n{datetime_pattern}{whitespace}Page 2\n\n\nabc\n{blank_lines_60}");
    let pattern = format!("{page1}{page2}");
    let regex = Regex::new(&pattern).unwrap();

    // Command line: `printf "\f\nabc" | pr`.
    new_ucmd!()
        .pipe_in("\x0c\nabc")
        .succeeds()
        .stdout_matches(&regex);
}