use crate::{UError, UErrorBt, UResult, cache::JobCache, executor::{Waiter, DynFut}, messaging::Reportable, models::{Agent, AssignedJob, JobMeta, JobType}, utils::{CombinedResult, OneOrVec}};
use guess_host_triple::guess_host_triple;
use std::collections::HashMap;

pub struct JobBuilder {
    waiter: Waiter,
}

impl JobBuilder {
    pub fn from_request(job_requests: impl OneOrVec<AssignedJob>) -> CombinedResult<Self> {
        let job_requests = job_requests.into_vec();
        let mut prepared: Vec<DynFut> = vec![];
        let mut result = CombinedResult::<JobBuilder, UErrorBt>::new();
        for req in job_requests {
            let job_meta = JobCache::get(req.job_id);
            if job_meta.is_none() {
                result.err(UError::NoJob(req.job_id).into_bt());
                continue;
            }
            let job_meta = job_meta.unwrap();
            //waiting for try-blocks stabilization
            let built_req = (|| -> UResult<()> {
                Ok(match job_meta.exec_type {
                    JobType::Shell => {
                        let meta = JobCache::get(req.job_id).ok_or(UError::NoJob(req.job_id))?;
                        let curr_platform = guess_host_triple().unwrap_or("unknown").to_string();
                        //TODO: extend platform checking (partial check)
                        if meta.platform != curr_platform {
                            return Err(UError::InsuitablePlatform(
                                meta.platform.clone(),
                                curr_platform,
                            ).into());
                        }
                        let job = AssignedJob::new(req.job_id, Some(&req));
                        prepared.push(Box::pin(job.run()))
                    }
                    JobType::Manage => prepared.push(Box::pin(Agent::run())),
                    _ => todo!(),
                })
            })();
            if let Err(e) = built_req {
                result.err(e)
            }
        }
        result.ok(Self {
            waiter: Waiter::new(prepared),
        });
        result
    }

    pub fn from_meta(job_metas: impl OneOrVec<JobMeta>) -> CombinedResult<Self> {
        let job_requests = job_metas
            .into_vec()
            .into_iter()
            .map(|jm| {
                let j_uid = jm.id;
                JobCache::insert(jm);
                AssignedJob::new(j_uid, None)
            })
            .collect::<Vec<AssignedJob>>();
        JobBuilder::from_request(job_requests)
    }

    /// Spawn jobs and pop results later
    pub async fn spawn(mut self) -> Self {
        self.waiter = self.waiter.spawn().await;
        self
    }

    /// Spawn jobs and wait for result
    pub async fn wait(self) -> Vec<Reportable> {
        self.waiter.spawn().await.wait().await
    }

    /// Spawn one job and wait for result
    pub async fn wait_one(self) -> Reportable {
        self.waiter.spawn().await.wait().await.pop().unwrap()
    }
}

/// Store jobs and get results by name
pub struct NamedJobBuilder {
    builder: Option<JobBuilder>,
    job_names: Vec<&'static str>,
    results: HashMap<&'static str, Reportable>,
}

impl NamedJobBuilder {
    pub fn from_shell(
        named_jobs: impl OneOrVec<(&'static str, &'static str)>,
    ) -> CombinedResult<Self> {
        let mut result = CombinedResult::new();
        let jobs: Vec<(&'static str, JobMeta)> = named_jobs
            .into_vec()
            .into_iter()
            .filter_map(
                |(alias, cmd)| match JobMeta::builder().with_shell(cmd).build() {
                    Ok(meta) => Some((alias, meta)),
                    Err(e) => {
                        result.err(e);
                        None
                    }
                },
            )
            .collect();
        result.ok(Self::from_meta(jobs));
        result
    }

    pub fn from_meta(named_jobs: impl OneOrVec<(&'static str, JobMeta)>) -> Self {
        let mut job_names = vec![];
        let job_metas: Vec<JobMeta> = named_jobs
            .into_vec()
            .into_iter()
            .map(|(alias, meta)| {
                job_names.push(alias);
                meta
            })
            .collect();
        Self {
            builder: Some(JobBuilder::from_meta(job_metas).unwrap_one()),
            job_names,
            results: HashMap::new(),
        }
    }

    pub async fn wait(mut self) -> Self {
        let results = self.builder.take().unwrap().wait().await;
        for (name, result) in self.job_names.iter().zip(results.into_iter()) {
            self.results.insert(name, result);
        }
        self
    }

    pub fn pop_opt(&mut self, name: &'static str) -> Option<Reportable> {
        self.results.remove(name)
    }

    pub fn pop(&mut self, name: &'static str) -> Reportable {
        self.pop_opt(name).unwrap()
    }
}

#[cfg(test)]
mod tests {

    use super::*;
    use test_case::test_case;
    use std::{time::SystemTime};
    use crate::{
        errors::UError,
        models::{
            JobMeta,
            misc::JobType
        },
        builder::{JobBuilder, NamedJobBuilder},
        unwrap_enum,
    };

    type TestResult<R = ()> = Result<R, Box<dyn std::error::Error>>;

    #[tokio::test]
    async fn test_is_really_async() {
        const SLEEP_SECS: u64 = 1;
        let job = JobMeta::from_shell(format!("sleep {}", SLEEP_SECS)).unwrap();
        let sleep_jobs: Vec<JobMeta> = (0..50).map(|_| job.clone()).collect();
        let now = SystemTime::now();
        JobBuilder::from_meta(sleep_jobs).unwrap_one().wait().await;
        assert!(now.elapsed().unwrap().as_secs() < SLEEP_SECS + 2)
    }

    #[test_case(
        "/bin/sh {}", 
        Some(b"echo test01 > /tmp/asd; cat /tmp/asd"), 
        "test01"
        ;"sh payload"
    )]
    #[test_case(
        r#"/usr/bin/python3 -c 'print("test02")'"#,
        None, 
        "test02"
        ;"python cmd"
    )]
    #[test_case(
        "/{}", 
        Some(
    br#"#!/bin/sh
    TMPPATH=/tmp/lol
    mkdir -p $TMPPATH
    echo test03 > $TMPPATH/t
    cat $TMPPATH/t
    rm -rf $TMPPATH"#
        ),
        "test03"
        ;"sh multiline payload"
    )]
    #[test_case(
        "/{} 'some msg as arg'",
        Some(include_bytes!("../tests/fixtures/echoer")),
        "some msg as arg"
        ;"standalone binary with args"
    )]
    #[tokio::test]
    async fn test_shell_job(cmd: &str, payload: Option<&[u8]>, expected_result: &str) -> TestResult {
        let mut job = JobMeta::builder().with_shell(cmd); 
        if let Some(p) = payload {
            job = job.with_payload(p);
        }
        let job = job.build().unwrap();
        let job_result = JobBuilder::from_meta(job).unwrap_one().wait_one().await;
        let result = unwrap_enum!(job_result, Reportable::Assigned);
        let result = result.to_string_result();
        assert_eq!(result.trim(), expected_result);
        Ok(())
    }

    #[tokio::test]
    async fn test_complex_load() -> TestResult {
        const SLEEP_SECS: u64 = 1;
        let now = SystemTime::now();
        let longest_job = JobMeta::from_shell(format!("sleep {}", SLEEP_SECS)).unwrap();
        let longest_job = JobBuilder::from_meta(longest_job).unwrap_one().spawn().await; 
        let ls = JobBuilder::from_meta(JobMeta::from_shell("ls")?).unwrap_one()
            .wait_one()
            .await;
        let ls = unwrap_enum!(ls, Reportable::Assigned);
        assert_eq!(ls.retcode.unwrap(), 0);
        let folders = ls.to_string_result();
        let subfolders_jobs: Vec<JobMeta> = folders
            .lines()
            .map(|f| JobMeta::from_shell(format!("ls {}", f)).unwrap())
            .collect();
        let ls_subfolders = JobBuilder::from_meta(subfolders_jobs)
            .unwrap_one()
            .wait()
            .await;
        for result in ls_subfolders {
            let result = unwrap_enum!(result, Reportable::Assigned);
            assert_eq!(result.retcode.unwrap(), 0);
        }
        longest_job.wait().await;
        assert_eq!(now.elapsed().unwrap().as_secs(), SLEEP_SECS);
        Ok(())
    }
    /*
    #[tokio::test]
    async fn test_exec_multiple_jobs_nowait() -> UResult<()> {
        const REPEATS: usize = 10;
        let job = JobMeta::from_shell("whoami");
        let sleep_jobs: Vec<JobMeta> = (0..=REPEATS).map(|_| job.clone()).collect();
        build_jobs(sleep_jobs).spawn().await;
        let mut completed = 0;
        while completed < REPEATS {
            let c = pop_completed().await.len();
            if c > 0 {
                completed += c;
                println!("{}", c);
            }
        }
        Ok(())
    }
    */
    #[tokio::test]
    async fn test_failing_shell_job() -> TestResult {
        let job = JobMeta::from_shell("lol_kek_puk")?;
        let job_result = JobBuilder::from_meta(job)
            .unwrap_one()
            .wait_one()
            .await;
        let job_result = unwrap_enum!(job_result, Reportable::Assigned);
        let output = job_result.to_string_result();
        assert!(output.contains("No such file"));
        assert!(job_result.retcode.is_none());
        Ok(())
    }

    #[test_case(
        "/bin/bash {}", 
        None, 
        "contains executable"
        ; "no binary"
    )]
    #[test_case(
        "/bin/bash", 
        Some(b"whoami"), 
        "contains no executable"
        ; "no path to binary"
    )]
    #[tokio::test]
    async fn test_job_building_failed(cmd: &str, payload: Option<&[u8]>, err_str: &str) -> TestResult {
        let mut job = JobMeta::builder().with_shell(cmd);
        if let Some(p) = payload {
            job = job.with_payload(p);
        }
        let err = job.build().unwrap_err();
        let err_msg = unwrap_enum!(err.err, UError::JobArgsError);
        assert!(err_msg.contains(err_str));
        Ok(())
    }

    #[tokio::test]
    async fn test_different_job_types() -> TestResult {
        let mut jobs = NamedJobBuilder::from_meta(vec![
            ("sleeper", JobMeta::from_shell("sleep 3")?),
            ("gatherer", JobMeta::builder().with_type(JobType::Manage).build()?)
        ]).wait().await;
        let gathered = jobs.pop("gatherer");
        assert_eq!(unwrap_enum!(gathered, Reportable::Agent).alias, None);
        Ok(())
    }

}