#[derive(PartialEq, Eq, Debug)]
pub struct Spec {
  pub file_name: String,
  pub message: String,
  pub file_text: String,
  pub expected_text: String,
  pub is_only: bool,
  pub is_trace: bool,
  pub skip: bool,
  pub skip_format_twice: bool,
  pub config: SpecConfigMap,
}

pub type SpecConfigMap = serde_json::Map<String, serde_json::Value>;

#[derive(Debug, Clone)]
pub struct ParseSpecOptions {
  /// The default file name for a parsed spec.
  pub default_file_name: &'static str,
}

pub fn parse_specs(file_text: String, options: &ParseSpecOptions) -> Vec<Spec> {
  // this function needs a rewrite
  let file_text = file_text.replace("\r\n", "\n");
  let (file_path, file_text) = parse_file_path(file_text, options);
  let (config, file_text) = parse_config(file_text);
  let lines = file_text.split('\n').collect::<Vec<_>>();
  let spec_starts = get_spec_starts(&file_path, &lines);
  let mut specs = Vec::new();

  for i in 0..spec_starts.len() {
    let start_index = spec_starts[i];
    let end_index = if spec_starts.len() == i + 1 { lines.len() } else { spec_starts[i + 1] };
    let message_line = lines[start_index];
    let spec = parse_single_spec(&file_path, message_line, &lines[(start_index + 1)..end_index], &config);

    specs.push(spec);
  }

  return specs;

  fn parse_file_path(file_text: String, options: &ParseSpecOptions) -> (String, String) {
    if !file_text.starts_with("--") {
      return (options.default_file_name.into(), file_text);
    }
    let last_index = file_text.find("--\n").expect("Could not find final --");

    (file_text["--".len()..last_index].trim().into(), file_text[(last_index + "--\n".len())..].into())
  }

  fn parse_config(file_text: String) -> (SpecConfigMap, String) {
    if !file_text.starts_with("~~") {
      return (Default::default(), file_text);
    }
    let last_index = file_text.find("~~\n").expect("Could not find final ~~\\n");

    let config_text = file_text["~~".len()..last_index].replace('\n', "");
    let config_text = config_text.trim();
    let mut config: SpecConfigMap = Default::default();

    if config_text.starts_with('{') {
      config = serde_json::from_str(config_text).expect("Error parsing config json.");
    } else {
      for item in config_text.split(',') {
        let first_colon = item.find(':').expect("Could not find colon in config option.");
        let key = item[0..first_colon].trim();
        let value = item[first_colon + ":".len()..].trim();

        config.insert(
          key.into(),
          match value.parse::<bool>() {
            Ok(value) => value.into(),
            Err(_) => match value.parse::<i32>() {
              Ok(value) => value.into(),
              Err(_) => value.into(),
            },
          },
        );
      }
    }

    (config, file_text[(last_index + "~~\n".len())..].into())
  }

  fn get_spec_starts(file_name: &str, lines: &[&str]) -> Vec<usize> {
    let mut result = Vec::new();
    let message_separator = get_message_separator(file_name);

    if !lines.first().unwrap().starts_with(message_separator) {
      panic!("All spec files should start with a message. (ex. {0} Message {0})", message_separator);
    }

    for (i, line) in lines.iter().enumerate() {
      if line.starts_with(message_separator) {
        result.push(i);
      }
    }

    result
  }

  fn parse_single_spec(file_name: &str, message_line: &str, lines: &[&str], config: &SpecConfigMap) -> Spec {
    let file_text = lines.join("\n");
    let parts = file_text.split("[expect]").collect::<Vec<&str>>();
    let start_text = parts[0][0..parts[0].len() - "\n".len()].into(); // remove last newline
    let expected_text = parts[1]["\n".len()..].into(); // remove first newline
    let lower_case_message_line = message_line.to_ascii_lowercase();
    let message_separator = get_message_separator(file_name);
    let is_trace = lower_case_message_line.contains("(trace)");

    Spec {
      file_name: String::from(file_name),
      message: message_line[message_separator.len()..message_line.len() - message_separator.len()]
        .trim()
        .into(),
      file_text: start_text,
      expected_text,
      is_only: lower_case_message_line.contains("(only)") || is_trace,
      is_trace,
      skip: lower_case_message_line.contains("(skip)"),
      skip_format_twice: lower_case_message_line.contains("(skip-format-twice)"),
      config: config.clone(),
    }
  }

  fn get_message_separator(file_name: &str) -> &'static str {
    if file_name.ends_with(".md") {
      "!!"
    } else {
      "=="
    }
  }
}

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

  #[test]
  fn it_parses() {
    let specs = parse_specs(
      vec![
        "== message 1 ==",
        "start",
        "multiple",
        "",
        "[expect]",
        "expected",
        "multiple",
        "",
        "== message 2 (only) (skip) (skip-format-twice) ==",
        "start2",
        "",
        "[expect]",
        "expected2",
        "",
        "== message 3 (trace) ==",
        "test",
        "",
        "[expect]",
        "test",
        "",
      ]
      .join("\n"),
      &ParseSpecOptions { default_file_name: "test.ts" },
    );

    assert_eq!(specs.len(), 3);
    assert_eq!(
      specs[0],
      Spec {
        file_name: "test.ts".into(),
        file_text: "start\nmultiple\n".into(),
        expected_text: "expected\nmultiple\n".into(),
        message: "message 1".into(),
        is_only: false,
        is_trace: false,
        skip: false,
        skip_format_twice: false,
        config: Default::default(),
      }
    );
    assert_eq!(
      specs[1],
      Spec {
        file_name: "test.ts".into(),
        file_text: "start2\n".into(),
        expected_text: "expected2\n".into(),
        message: "message 2 (only) (skip) (skip-format-twice)".into(),
        is_only: true,
        is_trace: false,
        skip: true,
        skip_format_twice: true,
        config: Default::default(),
      }
    );
    assert_eq!(
      specs[2],
      Spec {
        file_name: "test.ts".into(),
        file_text: "test\n".into(),
        expected_text: "test\n".into(),
        message: "message 3 (trace)".into(),
        is_only: true,
        is_trace: true,
        skip: false,
        skip_format_twice: false,
        config: Default::default(),
      }
    );
  }

  #[test]
  fn it_parses_with_file_name() {
    let specs = parse_specs(
      vec!["-- asdf.ts --", "== message ==", "start", "[expect]", "expected"].join("\n"),
      &ParseSpecOptions { default_file_name: "test.ts" },
    );

    assert_eq!(specs.len(), 1);
    assert_eq!(
      specs[0],
      Spec {
        file_name: "asdf.ts".into(),
        file_text: "start".into(),
        expected_text: "expected".into(),
        message: "message".into(),
        is_only: false,
        is_trace: false,
        skip: false,
        skip_format_twice: false,
        config: Default::default(),
      }
    );
  }

  #[test]
  fn it_parses_with_config() {
    let specs = parse_specs(
      vec![
        "-- asdf.ts --",
        "~~ test.test: other, lineWidth: 40 ~~",
        "== message ==",
        "start",
        "[expect]",
        "expected",
      ]
      .join("\n"),
      &ParseSpecOptions { default_file_name: "test.ts" },
    );

    assert_eq!(specs.len(), 1);
    assert_eq!(
      specs[0],
      Spec {
        file_name: "asdf.ts".into(),
        file_text: "start".into(),
        expected_text: "expected".into(),
        message: "message".into(),
        is_only: false,
        is_trace: false,
        skip: false,
        skip_format_twice: false,
        config: [("test.test".into(), "other".into()), ("lineWidth".into(), 40.into())]
          .iter()
          .cloned()
          .collect(),
      }
    );
  }

  #[test]
  fn it_parses_markdown() {
    let specs = parse_specs(
      vec![
        "!! message 1 !!",
        "start",
        "multiple",
        "",
        "[expect]",
        "expected",
        "multiple",
        "",
        "!! message 2 (only) (skip) (skip-format-twice) !!",
        "start2",
        "",
        "[expect]",
        "expected2",
        "",
      ]
      .join("\n"),
      &ParseSpecOptions { default_file_name: "test.md" },
    );

    assert_eq!(specs.len(), 2);
    assert_eq!(
      specs[0],
      Spec {
        file_name: "test.md".into(),
        file_text: "start\nmultiple\n".into(),
        expected_text: "expected\nmultiple\n".into(),
        message: "message 1".into(),
        is_only: false,
        is_trace: false,
        skip: false,
        skip_format_twice: false,
        config: Default::default(),
      }
    );
    assert_eq!(
      specs[1],
      Spec {
        file_name: "test.md".into(),
        file_text: "start2\n".into(),
        expected_text: "expected2\n".into(),
        message: "message 2 (only) (skip) (skip-format-twice)".into(),
        is_only: true,
        is_trace: false,
        skip: true,
        skip_format_twice: true,
        config: Default::default(),
      }
    );
  }
}