//! The `pact_verifier` crate provides the core logic to performing verification of providers.
//! It implements the V2 Pact specification (https://github.com/pact-foundation/pact-specification/tree/version-2).

#![warn(missing_docs)]

#[macro_use] extern crate pact_matching;
extern crate ansi_term;
#[macro_use] extern crate log;
extern crate hyper;
extern crate tokio;
extern crate futures;
extern crate bytes;
extern crate reqwest;
extern crate mime;
#[macro_use] extern crate maplit;
extern crate itertools;
extern crate regex;
extern crate difference;
#[macro_use] extern crate serde_json;

#[cfg(test)]
#[macro_use(expect)]
extern crate expectest;
#[cfg(test)]
#[macro_use]
extern crate pact_consumer;
#[cfg(test)]
extern crate env_logger;
#[cfg(test)]
extern crate http;

mod provider_client;
mod pact_broker;

use std::path::Path;
use std::io;
use std::fs;
use std::fmt::{Display, Formatter};
use pact_matching::*;
use pact_matching::models::*;
use pact_matching::models::provider_states::*;
use pact_matching::models::http_utils::HttpAuth;
use ansi_term::*;
use ansi_term::Colour::*;
use std::collections::HashMap;
use provider_client::{make_provider_request, make_state_change_request, ProviderClientError};
use regex::Regex;
use serde_json::Value;
use tokio::runtime::current_thread::Runtime;
use pact_broker::{publish_verification_results, TestResult, Link};

/// Source for loading pacts
#[derive(Debug, Clone)]
pub enum PactSource {
    /// Unknown pact source
    Unknown,
    /// Load the pact from a pact file
    File(String),
    /// Load all the pacts from a Directory
    Dir(String),
    /// Load the pact from a URL
    URL(String, Option<HttpAuth>),
    /// Load all pacts with the provider name from the pact broker url
    BrokerUrl(String, String, Option<HttpAuth>, Vec<Link>)
}

impl Display for PactSource {
  fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
    match self {
      &PactSource::File(ref file) => write!(f, "File({})", file),
      &PactSource::Dir(ref dir) => write!(f, "Dir({})", dir),
      &PactSource::URL(ref url, _) => write!(f, "URL({})", url),
      &PactSource::BrokerUrl(ref provider_name, ref broker_url, _, _) => {
        write!(f, "PactBroker({}, provider_name='{}')", broker_url, provider_name)
      }
      _ => write!(f, "Unknown")
    }
  }
}

/// Information about the Provider to verify
#[derive(Debug, Clone)]
pub struct ProviderInfo {
    /// Provider Name
    pub name: String,
    /// Provider protocol, defaults to HTTP
    pub protocol: String,
    /// Hostname of the provider
    pub host: String,
    /// Port the provider is running on, defaults to 8080
    pub port: u16,
    /// Base path for the provider, defaults to /
    pub path: String,
    /// URL to post state change requests to
    pub state_change_url: Option<String>,
    /// If teardown state change requests should be made (default is false)
    pub state_change_teardown: bool,
    /// If state change request data should be sent in the body (true) or as query parameters (false)
    pub state_change_body: bool
}

impl ProviderInfo {
    /// Create a default provider info
    pub fn default() -> ProviderInfo {
        ProviderInfo {
            name: s!("provider"),
            protocol: s!("http"),
            host: s!("localhost"),
            port: 8080,
            path: s!("/"),
            state_change_url: None,
            state_change_teardown: false,
            state_change_body: true
        }
    }
}

/// Result of performing a match
#[derive(Debug, Clone)]
pub enum MismatchResult {
    /// Response mismatches
    Mismatches {
      /// Mismatches that occurred
      mismatches: Vec<Mismatch>,
      /// Expected Response
      expected: Response,
      /// Actual Response
      actual: Response,
      /// Interaction ID if fetched from a pact broker
      interaction_id: Option<String>
    },
    /// Error occurred
    Error(String, Option<String>)
}

impl MismatchResult {
  /// Return the interaction ID associated with the error, if any
  pub fn interaction_id(&self) -> Option<String> {
    match self {
      &MismatchResult::Mismatches { ref interaction_id, .. } => interaction_id.clone(),
      &MismatchResult::Error(_, ref interaction_id) => interaction_id.clone()
    }
  }
}

fn provider_client_error_to_string(err: ProviderClientError) -> String {
    match err {
        ProviderClientError::RequestMethodError(ref method, _) =>
            format!("Invalid request method: '{}'", method),
        ProviderClientError::RequestHeaderNameError(ref name, _) =>
            format!("Invalid header name: '{}'", name),
        ProviderClientError::RequestHeaderValueError(ref value, _) =>
            format!("Invalid header value: '{}'", value),
        ProviderClientError::RequestBodyError(ref message) =>
            format!("Invalid request body: '{}'", message),
        ProviderClientError::ResponseError(ref message) =>
            format!("Invalid response: {}", message),
        ProviderClientError::ResponseStatusCodeError(ref code) =>
            format!("Invalid status code: {}", code)
    }
}

fn verify_response_from_provider(provider: &ProviderInfo, interaction: &Interaction, runtime: &mut Runtime) -> Result<(), MismatchResult> {
  let ref expected_response = interaction.response;
  match runtime.block_on(make_provider_request(provider, &pact_matching::generate_request(&interaction.request, &hashmap!{}))) {
    Ok(ref actual_response) => {
      let mismatches = match_response(expected_response.clone(), actual_response.clone());
      if mismatches.is_empty() {
        Ok(())
      } else {
        Err(MismatchResult::Mismatches {
          mismatches,
          expected: expected_response.clone(),
          actual: actual_response.clone(),
          interaction_id: interaction.id.clone()
        })
      }
    },
    Err(err) => {
      Err(MismatchResult::Error(provider_client_error_to_string(err), interaction.id.clone()))
    }
  }
}

fn execute_state_change(provider_state: &ProviderState, provider: &ProviderInfo, setup: bool,
  runtime: &mut Runtime, interaction_id: Option<String>) -> Result<(), MismatchResult> {
    if setup {
        println!("  Given {}", Style::new().bold().paint(provider_state.name.clone()));
    }
    let result = match provider.state_change_url {
        Some(_) => {
            let mut state_change_request = Request { method: s!("POST"), .. Request::default() };
            if provider.state_change_body {
              let mut json_body = json!({
                  s!("state") : json!(provider_state.name.clone()),
                  s!("action") : json!(if setup {
                    s!("setup")
                  } else {
                    s!("teardown")
                  })
              });
              {
                let json_body_mut = json_body.as_object_mut().unwrap();
                for (k, v) in provider_state.params.clone() {
                  json_body_mut.insert(k, v);
                }
              }
              state_change_request.body = OptionalBody::Present(json_body.to_string().into());
              state_change_request.headers = Some(hashmap!{ s!("Content-Type") => vec![s!("application/json")] });
            } else {
              let mut query = hashmap!{ s!("state") => vec![provider_state.name.clone()] };
              if setup {
                query.insert(s!("action"), vec![s!("setup")]);
              } else {
                query.insert(s!("action"), vec![s!("teardown")]);
              }
              for (k, v) in provider_state.params.clone() {
                query.insert(k, vec![match v {
                  Value::String(ref s) => s.clone(),
                  _ => v.to_string()
                }]);
              }
              state_change_request.query = Some(query);
            }
            match runtime.block_on(make_state_change_request(provider, &state_change_request)) {
                Ok(_) => Ok(()),
                Err(err) => Err(MismatchResult::Error(provider_client_error_to_string(err), interaction_id))
            }
        },
        None => {
            if setup {
                println!("    {}", Yellow.paint("WARNING: State Change ignored as there is no state change URL"));
            }
            Ok(())
        }
    };

    debug!("State Change: \"{:?}\" -> {:?}", provider_state, result);
    result
}

fn verify_interaction(provider: &ProviderInfo, interaction: &Interaction, runtime: &mut Runtime) -> Result<(), MismatchResult> {
    for state in interaction.provider_states.clone() {
      execute_state_change(&state, provider, true, runtime, interaction.id.clone())?
    }

    let result = verify_response_from_provider(provider, interaction, runtime);

    if provider.state_change_teardown {
      for state in interaction.provider_states.clone() {
        execute_state_change(&state, provider, false, runtime, interaction.id.clone())?
      }
    }

    result
}

fn display_result(status: u16, status_result: ANSIGenericString<str>,
    header_results: Option<Vec<(String, String, ANSIGenericString<str>)>>,
    body_result: ANSIGenericString<str>) {
    println!("    returns a response which");
    println!("      has status code {} ({})", Style::new().bold().paint(format!("{}", status)),
        status_result);
    match header_results {
        Some(header_results) => {
            println!("      includes headers");
            for (key, value, result) in header_results {
                println!("        \"{}\" with value \"{}\" ({})", Style::new().bold().paint(key),
                    Style::new().bold().paint(value), result);
            }
        },
        None => ()
    }
    println!("      has a matching body ({})", body_result);
}

fn walkdir(dir: &Path) -> io::Result<Vec<io::Result<Pact>>> {
    let mut pacts = vec![];
    debug!("Scanning {:?}", dir);
    for entry in fs::read_dir(dir)? {
        let entry = entry?;
        let path = entry.path();
        if path.is_dir() {
            walkdir(&path)?;
        } else {
            pacts.push(Pact::read_pact(&path))
        }
    }
    Ok(pacts)
}

fn display_body_mismatch(expected: &Response, actual: &Response, path: &String) {
    match expected.content_type_enum() {
        DetectedContentType::Json => println!("{}", pact_matching::json::display_diff(&expected.body.str_value().to_string(),
            &actual.body.str_value().to_string(), path)),
        _ => ()
    }
}

/// Filter information used to filter the interactions that are verified
pub enum FilterInfo {
    /// No filter, all interactions will be verified
    None,
    /// Filter on the interaction description
    Description(String),
    /// Filter on the interaction provider state
    State(String),
    /// Filter on both the interaction description and provider state
    DescriptionAndState(String, String)
}

impl FilterInfo {

    /// If this filter is filtering on description
    pub fn has_description(&self) -> bool {
        match self {
            &FilterInfo::Description(_) => true,
            &FilterInfo::DescriptionAndState(_, _) => true,
            _ => false
        }
    }

    /// If this filter is filtering on provider state
    pub fn has_state(&self) -> bool {
        match self {
            &FilterInfo::State(_) => true,
            &FilterInfo::DescriptionAndState(_, _) => true,
            _ => false
        }
    }

    /// Value of the state to filter
    pub fn state(&self) -> String {
        match self {
            &FilterInfo::State(ref s) => s.clone(),
            &FilterInfo::DescriptionAndState(_, ref s) => s.clone(),
            _ => s!("")
        }
    }

    /// Value of the description to filter
    pub fn description(&self) -> String {
        match self {
            &FilterInfo::Description(ref s) => s.clone(),
            &FilterInfo::DescriptionAndState(ref s, _) => s.clone(),
            _ => s!("")
        }
    }

    /// If the filter matches the interaction provider state using a regular expression. If the
    /// filter value is the empty string, then it will match interactions with no provider state.
    ///
    /// # Panics
    /// If the state filter value can't be parsed as a regular expression
    pub fn match_state(&self, interaction: &Interaction) -> bool {
        if !interaction.provider_states.is_empty() {
            if self.state().is_empty() {
                false
            } else {
                let re = Regex::new(&self.state()).unwrap();
                interaction.provider_states.iter().any(|state| re.is_match(&state.name))
            }
        } else {
            self.has_state() && self.state().is_empty()
        }
    }

    /// If the filter matches the interaction description using a regular expression
    ///
    /// # Panics
    /// If the description filter value can't be parsed as a regular expression
    pub fn match_description(&self, interaction: &Interaction) -> bool {
        let re = Regex::new(&self.description()).unwrap();
        re.is_match(&interaction.description)
    }

}

fn filter_interaction(interaction: &Interaction, filter: &FilterInfo) -> bool {
    if filter.has_description() && filter.has_state() {
      filter.match_description(interaction) && filter.match_state(interaction)
    } else if filter.has_description() {
      filter.match_description(interaction)
    } else if filter.has_state() {
      filter.match_state(interaction)
    } else {
      true
    }
}

fn filter_consumers(consumers: &Vec<String>, res: &Result<(Pact, PactSource), String>) -> bool {
    consumers.is_empty() || res.is_err() || consumers.contains(&res.clone().unwrap().0.consumer.name)
}

/// Options to use when running the verification
pub struct VerificationOptions {
  /// If results should be published back to the broker
  pub publish: bool,
  /// Provider version being published
  pub provider_version: Option<String>,
  /// Build URL to associate with the published results
  pub build_url: Option<String>
}

/// Verify the provider with the given pact sources
pub fn verify_provider(provider_info: &ProviderInfo, source: Vec<PactSource>, filter: &FilterInfo,
    consumers: &Vec<String>, options: &VerificationOptions, runtime: &mut Runtime) -> bool {
    let pacts = fetch_pacts(&source, consumers, runtime);

    let mut verify_provider_result = true;
    let mut all_errors: Vec<(String, MismatchResult)> = vec![];
    for pact in pacts {
      match pact {
        Ok(ref res) => {
          let pact = &res.0;
            println!("\nVerifying a pact between {} and {}",
                Style::new().bold().paint(pact.consumer.name.clone()),
                Style::new().bold().paint(pact.provider.name.clone()));

            if pact.interactions.is_empty() {
              println!("         {}", Yellow.paint("WARNING: Pact file has no interactions"));
            } else {
              let errors = verify_pact(provider_info, filter, runtime, verify_provider_result, pact);
              for error in errors.clone() {
                all_errors.push(error);
              }

              if options.publish {
                publish_result(&errors, &res.1, &options, runtime)
              }
            }
        },
        Err(err) => {
            error!("Failed to load pact - {}", Red.paint(format!("{}", err)));
            verify_provider_result = false;
            all_errors.push((s!("Failed to load pact"), MismatchResult::Error(format!("{}", err), None)));
        }
      }
    };

    if !all_errors.is_empty() {
        println!("\nFailures:\n");

        for (i, &(ref description, ref mismatch)) in all_errors.iter().enumerate() {
          match mismatch {
            &MismatchResult::Error(ref err, _) => println!("{}) {} - {}\n", i, description, err),
            &MismatchResult::Mismatches { ref mismatches, ref expected, ref actual, .. } => {
              let mismatch = mismatches.first().unwrap();
              println!("{}) {}{}", i, description, mismatch.summary());
              for mismatch in mismatches {
                println!("    {}\n", mismatch.ansi_description());
              }

              match mismatch {
                &Mismatch::BodyMismatch{ref path, ..} => display_body_mismatch(expected, actual, path),
                _ => ()
              }
            }
          }
        }

        println!("\nThere were {} pact failures\n", all_errors.len());
    }

    verify_provider_result
}

fn fetch_pacts(source: &Vec<PactSource>, consumers: &Vec<String>, runtime: &mut Runtime) -> Vec<Result<(Pact, PactSource), String>> {
  source.iter().flat_map(|s| {
    match s {
      &PactSource::File(ref file) => vec![Pact::read_pact(Path::new(&file))
        .map_err(|err| format!("Failed to load pact '{}' - {}", file, err))
        .map(|pact| (pact, s.clone()))],
      &PactSource::Dir(ref dir) => match walkdir(Path::new(dir)) {
        Ok(ref pacts) => pacts.iter().map(|p| {
          match p {
            &Ok(ref pact) => Ok((pact.clone(), s.clone())),
            &Err(ref err) => Err(format!("Failed to load pact from '{}' - {}", dir, err))
          }
        }).collect(),
        Err(err) => vec![Err(format!("Could not load pacts from directory '{}' - {}", dir, err))]
      },
      &PactSource::URL(ref url, ref auth) => vec![Pact::from_url(url, auth)
        .map_err(|err| format!("Failed to load pact '{}' - {}", url, err))
        .map(|pact| (pact, s.clone()))],
      &PactSource::BrokerUrl(ref provider_name, ref broker_url, ref auth, _) => {
        let future = pact_broker::fetch_pacts_from_broker(broker_url.clone(), provider_name.clone(), auth.clone());
        match runtime.block_on(future) {
          Ok(ref pacts) => pacts.iter().map(|p| {
            match p {
              &Ok((ref pact, ref links)) => {
                debug!("Got pact with links {:?}", links);
                Ok((pact.clone(), PactSource::BrokerUrl(provider_name.clone(), broker_url.clone(), auth.clone(), links.clone())))
              },
              &Err(ref err) => Err(format!("Failed to load pact from '{}' - {:?}", broker_url, err))
            }
          }).collect(),
          Err(err) => vec![Err(format!("Could not load pacts from the pact broker '{}' - {:?}", broker_url, err))]
        }
      },
      _ => vec![Err(format!("Could not load pacts, unknown pact source"))]
    }
  })
    .filter(|res| filter_consumers(consumers, res))
    .collect()
}

fn verify_pact(provider_info: &ProviderInfo, filter: &FilterInfo, runtime: &mut Runtime,
               mut verify_provider_result: bool, pact: &Pact) -> Vec<(String, MismatchResult)> {
  let mut errors = vec![];

  let results: HashMap<Interaction, Result<(), MismatchResult>> = pact.interactions.iter()
    .filter(|interaction| filter_interaction(interaction, filter))
    .map(|interaction| {
      (interaction.clone(), verify_interaction(provider_info, interaction, runtime))
    }).collect();

  for (interaction, result) in results.clone() {
    let mut description = format!("Verifying a pact between {} and {}",
                                  pact.consumer.name.clone(), pact.provider.name.clone());
    if let Some((first, elements)) = interaction.provider_states.split_first() {
      description.push_str(&format!(" Given {}", first.name));
      for state in elements {
        description.push_str(&format!(" And {}", state.name));
      }
    }
    description.push_str(" - ");
    description.push_str(&interaction.description);
    println!("  {}", interaction.description);
    match result {
      Ok(()) => {
        display_result(interaction.response.status, Green.paint("OK"),
                       interaction.response.headers.map(|h| h.iter().map(|(k, v)| {
                         (k.clone(), v.join(", "), Green.paint("OK"))
                       }).collect()), Green.paint("OK"))

      },
      Err(ref err) => match err {
        &MismatchResult::Error(ref err_des, _) => {
          println!("      {}", Red.paint(format!("Request Failed - {}", err_des)));
          errors.push((description, err.clone()));
          verify_provider_result = false;
        },
        &MismatchResult::Mismatches { ref mismatches, .. } => {
          description.push_str(" returns a response which ");
          let status_result = if mismatches.iter().any(|m| m.mismatch_type() == s!("StatusMismatch")) {
            verify_provider_result = false;
            Red.paint("FAILED")
          } else {
            Green.paint("OK")
          };
          let header_results = match interaction.response.headers {
            Some(ref h) => Some(h.iter().map(|(k, v)| {
              (k.clone(), v.join(", "), if mismatches.iter().any(|m| {
                match m {
                  &Mismatch::HeaderMismatch { ref key, .. } => k == key,
                  _ => false
                }
              }) {
                verify_provider_result = false;
                Red.paint("FAILED")
              } else {
                Green.paint("OK")
              })
            }).collect()),
            None => None
          };
          let body_result = if mismatches.iter().any(|m| m.mismatch_type() == s!("BodyMismatch") ||
            m.mismatch_type() == s!("BodyTypeMismatch")) {
            verify_provider_result = false;
            Red.paint("FAILED")
          } else {
            Green.paint("OK")
          };

          display_result(interaction.response.status, status_result, header_results, body_result);
          errors.push((description.clone(), err.clone()));
        }
      }
    }
  }

  println!();

  errors
}

fn publish_result(errors: &Vec<(String, MismatchResult)>, source: &PactSource,
  options: &VerificationOptions, runtime: &mut Runtime) {
  match source.clone() {
    PactSource::BrokerUrl(_, broker_url, auth, links) => {
      info!("Publishing verification results back to the Pact Broker");
      let result = if errors.is_empty() {
        debug!("Publishing a successful result to {}", source);
        TestResult::Ok
      } else {
        debug!("Publishing a failure result to {}", source);
        TestResult::Failed(errors.clone())
      };
      let provider_version = options.provider_version.clone().unwrap();
      let future = publish_verification_results(links, broker_url.clone(), auth.clone(),
        result, provider_version, options.build_url.clone());
      match runtime.block_on(future) {
        Ok(_) => info!("Results published to Pact Broker"),
        Err(ref err) => error!("Publishing of verification results failed with an error: {}", err)
      };
    },
    _ => ()
  }
}

#[cfg(test)]
mod tests;