use crate::App;

use anyhow::{anyhow, bail};
use clap::Args;
use codespan_reporting::files::SimpleFile;
use jsona::{
    dom::{DomNode, Keys, Node},
    parser,
};
use jsona_util::environment::Environment;
use serde_json::{json, Value};
use tokio::io::{AsyncReadExt, AsyncWriteExt};

impl<E: Environment> App<E> {
    pub async fn execute_get(&self, cmd: GetCommand) -> Result<(), anyhow::Error> {
        let mut stdout = self.env.stdout();

        let source = match &cmd.file_path {
            Some(p) => {
                let (_, source) = self.load_file(p).await?;
                source
            }
            None => {
                let mut stdin = self.env.stdin();
                let mut s = String::new();
                stdin.read_to_string(&mut s).await?;
                s
            }
        };

        let parse = parser::parse(&source);

        let file_path = cmd.file_path.as_deref().unwrap_or("-");

        self.print_parse_errors(&SimpleFile::new(file_path, &source), &parse.errors)
            .await?;

        if !parse.errors.is_empty() {
            return Err(anyhow!("syntax errors found"));
        }

        let node = parse.into_dom();

        if let Err(errors) = node.validate() {
            self.print_semantic_errors(&SimpleFile::new(file_path, &source), errors)
                .await?;

            return Err(anyhow!("semantic errors found"));
        }

        let nodes = match cmd.pattern {
            Some(p) => {
                let p = p.trim_start_matches('.');

                let keys = p
                    .parse::<Keys>()
                    .map_err(|err| anyhow!("invalid pattern: {err}"))?;

                node.matches_all(keys, false)
                    .map_err(|err| anyhow!("invalid pattern: {err}"))?
                    .map(|(_, v)| v)
                    .collect()
            }
            None => vec![node],
        };
        let buf = {
            let items: Vec<Value> = if cmd.annotation {
                nodes.iter().map(to_json).collect()
            } else {
                nodes.iter().map(|v| v.to_plain_json()).collect()
            };
            let value = match items.len() {
                0 => {
                    bail!("no found");
                }
                1 => items[0].clone(),
                _ => Value::Array(items),
            };
            if let Some(value) = value.as_str() {
                value.as_bytes().to_vec()
            } else {
                serde_json::to_vec_pretty(&value).unwrap()
            }
        };
        stdout.write_all(&buf).await?;
        stdout.flush().await?;
        Ok(())
    }
}

#[derive(Debug, Clone, Args)]
pub struct GetCommand {
    /// Whether output includes annotation
    #[clap(short = 'A', long)]
    pub annotation: bool,

    /// Path to the JSONA document, if omitted the standard input will be used.
    #[clap(short, long)]
    pub file_path: Option<String>,

    /// A dotted key pattern to the value within the JSONA document.
    ///
    /// If omitted, the entire document will be printed.
    ///
    /// If the pattern yielded no values, the operation will fail.
    ///
    /// The pattern supports `jq`-like syntax and glob patterns as well:
    ///
    /// Examples:
    ///
    /// - table.array[1].foo
    /// - table.array.1.foo
    /// - table.array[*].foo
    /// - table.array.*.foo
    /// - dependencies.tokio-*.version
    ///
    pub pattern: Option<String>,
}

pub fn to_json(node: &Node) -> Value {
    let annotations = node.annotations().map(|a| {
        Value::Object(
            a.value()
                .read()
                .kv_iter()
                .map(|(k, v)| (k.to_string(), v.to_plain_json()))
                .collect(),
        )
    });
    match node {
        Node::Null(_) => match annotations {
            Some(annotations) => {
                json!({
                    "value": null,
                    "annotations": annotations
                })
            }
            None => {
                json!({
                    "value": null,
                })
            }
        },
        Node::Bool(v) => match annotations {
            Some(annotations) => {
                json!({
                    "value": v.value(),
                    "annotations": annotations
                })
            }
            None => {
                json!({
                    "value": v.value(),
                })
            }
        },
        Node::Number(v) => match annotations {
            Some(annotations) => {
                json!({
                    "value": v.value(),
                    "annotations": annotations
                })
            }
            None => {
                json!({
                    "value": v.value(),
                })
            }
        },
        Node::String(v) => match annotations {
            Some(annotations) => {
                json!({
                    "value": v.value(),
                    "annotations": annotations
                })
            }
            None => {
                json!({
                    "value": v.value(),
                })
            }
        },
        Node::Array(v) => {
            let value = Value::Array(v.value().read().iter().map(to_json).collect());
            match annotations {
                Some(annotations) => {
                    json!({
                        "value": value,
                        "annotations": annotations
                    })
                }
                None => {
                    json!({
                        "value": value,
                    })
                }
            }
        }
        Node::Object(v) => {
            let value = Value::Object(
                v.value()
                    .read()
                    .kv_iter()
                    .map(|(k, v)| (k.to_string(), to_json(v)))
                    .collect(),
            );
            match annotations {
                Some(annotations) => {
                    json!({
                        "value": value,
                        "annotations": annotations
                    })
                }
                None => {
                    json!({
                        "value": value,
                    })
                }
            }
        }
    }
}