use super::{generate::Generate, sync_down::SyncDown, sync_up::SyncUp};
use crate::configuration::Configuration;
use crate::constants::METADATA_FILENAME;
use crate::metadata::Metadata;
use serde_json;
use std::fs::{copy, create_dir_all, read_dir, remove_dir_all, write};
use std::io::{Error, ErrorKind, Result};
use std::path::{Path, PathBuf};

pub struct Update;

impl Update {
    pub fn new() -> Self {
        Update
    }

    fn copy_post(source: &PathBuf, target: &Path) -> Result<()> {
        let post_name = source
            .file_name()
            .ok_or_else(|| Error::new(ErrorKind::InvalidInput, "Could not get post filename."))?;

        let target_post = target.join(post_name);
        copy(source, target_post)?;
        Ok(())
    }

    fn write_metadata(metadata: &Metadata, metadata_location: &PathBuf) -> Result<()> {
        let serialized_metadata = serde_json::to_string(&metadata)?;
        write(metadata_location, serialized_metadata)?;
        Ok(())
    }

    fn archive(source: &PathBuf, target: &Path) -> Result<()> {
        let entries = read_dir(source)?;
        for entry in entries {
            let entry = entry?;
            let entry_type = entry.file_type()?;
            let entry_name = entry.file_name();
            let entry_source = entry.path();
            let entry_target = target.join(entry_name);

            if entry_type.is_dir() {
                create_dir_all(&entry_target)?;
                Update::archive(&entry_source, &entry_target)?;
            } else {
                copy(&entry_source, &entry_target)?;
            }
        }

        Ok(())
    }
}

impl super::Command for Update {
    fn before_dependencies(&self) -> Vec<Box<dyn super::Command>> {
        vec![Box::new(SyncDown::new())]
    }

    fn execute(
        &self,
        input: Option<&String>,
        configuration: &Configuration,
        _: &str,
    ) -> Result<()> {
        let input = input.ok_or_else(|| {
            Error::new(ErrorKind::InvalidInput, "You must provide a path to a post")
        })?;
        let post_location = PathBuf::from(input);
        if !post_location.exists() {
            return Err(Error::new(
                ErrorKind::NotFound,
                "The path provided does not exist",
            ));
        }

        // Step 1. Write into the ephemeral posts

        create_dir_all(&configuration.posts_directory)?;

        let first_post_path = configuration.posts_directory.join("0");
        let metadata_file_path = first_post_path.join(METADATA_FILENAME);
        let metadata = Metadata::read_or_create(&metadata_file_path);

        let _ = remove_dir_all(&first_post_path);
        create_dir_all(&first_post_path)?;

        Update::copy_post(&post_location, &first_post_path)?;
        Update::write_metadata(&metadata, &metadata_file_path)?;

        // Step 2. Write into the archive

        create_dir_all(&configuration.archive_directory)?;

        let post_archive_path = configuration.archive_directory.join(metadata.id);
        let _ = remove_dir_all(&post_archive_path);
        create_dir_all(&post_archive_path)?;

        Update::archive(&first_post_path, &post_archive_path)?;
        Ok(())
    }

    fn after_dependencies(&self) -> Vec<Box<dyn super::Command>> {
        vec![Box::new(Generate::new()), Box::new(SyncUp::new())]
    }

    fn command(&self) -> &'static str {
        "update"
    }

    fn help(&self) -> &'static str {
        "<path_to_post>\t\tUpdates latest blog post"
    }
}

#[cfg(test)]
mod tests {
    use std::fs::{create_dir_all, read_dir};
    use std::path::PathBuf;

    use super::*;
    use crate::command::Command;
    use crate::configuration::Configuration;

    use test_utilities::*;

    #[test]
    fn test_update_command() {
        let update = Update::new();

        // Create all directories
        let test_dir = setup_test_dir();

        // Reference but don't create the directories
        let posts_dir = test_dir.join("posts");
        let archive_dir = test_dir.join("archive");

        // Create configuration
        let mut configuration = Configuration::new();
        configuration.posts_directory = posts_dir.clone();
        configuration.archive_directory = archive_dir.clone();

        // Create Test File
        let test_file = test_dir.join("cool-test-file-😎.gmi");
        let test_file_string = test_file.display().to_string();
        create_test_file(&test_file, "# I try.");

        // Update 1 of 2
        update
            .execute(Some(&test_file_string), &configuration, "update")
            .expect("Could not update a .gmi");
        assert!(&posts_dir.join("0").exists());
        assert_file_contents(&posts_dir.join("0/cool-test-file-😎.gmi"), "# I try.");

        let entries = read_dir(&archive_dir).expect("Could not read archive");
        let mut found_path = PathBuf::new();
        for entry in entries {
            let entry = entry.expect("Could not read entry");
            found_path = entry.path();
            assert_file_contents(&found_path.join("cool-test-file-😎.gmi"), "# I try.");
            assert!(&found_path.join("metadata.json").exists());
        }

        // Create Second Test File
        let second_test_file = test_dir.join("cooler-test-file-😎.gmi");
        let second_test_file_string = second_test_file.display().to_string();
        create_test_file(&second_test_file, "# I REALLY try.");

        // Update 2 of 2
        update
            .execute(Some(&second_test_file_string), &configuration, "update")
            .expect("Could not update a .gmi");
        assert_file_contents(
            &posts_dir.join("0/cooler-test-file-😎.gmi"),
            "# I REALLY try.",
        );
        assert_file_contents(
            &found_path.join("cooler-test-file-😎.gmi"),
            "# I REALLY try.",
        );

        cleanup_test_dir(&test_dir);
    }

    #[test]
    fn test_write_metadata_fail() {
        // Create all directories
        let test_dir = setup_test_dir();

        // Reference but don't create the directories
        let metadata_dir = test_dir.join("metadata/nested/cannot/write");

        // Create metadata
        let metadata = Metadata {
            id: "1234".to_string(),
            created_on: 1234,
        };

        // Update 1 of 2
        let result = Update::write_metadata(&metadata, &metadata_dir);
        assert!(result.is_err());

        cleanup_test_dir(&test_dir);
    }

    #[test]
    fn test_recursive_archive() {
        // Create all directories
        let test_dir = setup_test_dir();

        // Create the directories
        let source_dir = test_dir.join("source");
        let target_dir = test_dir.join("target");
        let nested_dir = source_dir.join("nested");
        create_dir_all(&nested_dir).expect("Could not create source dir.");
        create_dir_all(&target_dir).expect("Could not create target dir.");

        // Create the two test files.
        let test_file = source_dir.join("not_nested.gmi");
        let nested_test_file = nested_dir.join("very_much_nested.gmi");
        create_test_file(&test_file, "# Unlike a Bird");
        create_test_file(&nested_test_file, "# Very much like a Bird");

        Update::archive(&source_dir, &target_dir).expect("Could not archive the test directories");

        assert_file_contents(&target_dir.join("not_nested.gmi"), "# Unlike a Bird");
        assert_file_contents(
            &target_dir.join("nested/very_much_nested.gmi"),
            "# Very much like a Bird",
        );

        cleanup_test_dir(&test_dir);
    }

    #[test]
    fn test_update_fails_on_directory() {
        let update = Update::new();

        // Create all directories
        let test_dir = setup_test_dir();

        // Reference but don't create the directories
        let nested_dir = test_dir.join("nested");
        let posts_dir = test_dir.join("posts");
        let archive_dir = test_dir.join("archive");
        create_dir_all(&nested_dir).expect("Could not create nested dir.");

        // Create configuration
        let mut configuration = Configuration::new();
        configuration.posts_directory = posts_dir.clone();
        configuration.archive_directory = archive_dir.clone();

        // Create Test File
        let test_file = nested_dir.join("cool-test-file-😎.gmi");
        create_test_file(&test_file, "# I try.");
        let nested_string = nested_dir.display().to_string();

        let result = update.execute(Some(&nested_string), &configuration, "update");
        assert!(result.is_err());
        cleanup_test_dir(&test_dir);
    }

    #[test]
    fn test_update_fails_on_missing_input() {
        let update = Update::new();

        // Create all directories
        let test_dir = setup_test_dir();

        // Reference but don't create the directories
        let posts_dir = test_dir.join("posts");
        let archive_dir = test_dir.join("archive");

        // Create configuration
        let mut configuration = Configuration::new();
        configuration.posts_directory = posts_dir.clone();
        configuration.archive_directory = archive_dir.clone();

        // Add 1 of 3
        let result = update.execute(None, &configuration, "update");
        assert!(result.is_err());
        cleanup_test_dir(&test_dir);
    }

    #[test]
    fn test_update_fails_if_file_does_not_exist() {
        let update = Update::new();

        // Create all directories
        let test_dir = setup_test_dir();

        // Reference but don't create the directories
        let posts_dir = test_dir.join("posts");
        let archive_dir = test_dir.join("archive");

        // Create configuration
        let mut configuration = Configuration::new();
        configuration.posts_directory = posts_dir.clone();
        configuration.archive_directory = archive_dir.clone();

        // Create Test File
        let test_file = test_dir.join("cool-secret-test-file-😎.gmi");
        let test_file_string = test_file.display().to_string();

        // Add 1 of 3
        let result = update.execute(Some(&test_file_string), &configuration, "update");
        assert!(result.is_err());

        cleanup_test_dir(&test_dir);
    }

    #[test]
    fn update_before_dependencies() {
        let update = Update::new();
        let dependencies = update.before_dependencies();

        assert_eq!(dependencies.len(), 1);
        assert_eq!(dependencies[0].command(), "sync-down");
    }

    #[test]
    fn update_after_dependencies() {
        let update = Update::new();
        let dependencies = update.after_dependencies();

        assert_eq!(dependencies.len(), 2);
        assert_eq!(dependencies[0].command(), "generate");
        assert_eq!(dependencies[1].command(), "sync-up");
    }

    // These two tests feel pointless but I'm doing it for the coverage :p

    #[test]
    fn update_command_output() {
        let update = Update::new();
        update.command();
    }

    #[test]
    fn update_help_output() {
        let update = Update::new();
        update.help();
    }
}