use api_entity_crud::EntityCrud;
use data_encoding::BASE32_NOPAD;
use database_models::*;
use database_schema::*;
use diesel;
use diesel::prelude::*;
use errors::*;
use fatcat_api_spec::models::*;
use regex::Regex;
use serde_json;
use std::str::FromStr;
use uuid::Uuid;

pub type DbConn =
    diesel::r2d2::PooledConnection<diesel::r2d2::ConnectionManager<diesel::PgConnection>>;

pub struct EditContext {
    pub editor_id: FatCatId,
    pub editgroup_id: FatCatId,
    pub extra_json: Option<serde_json::Value>,
    pub autoaccept: bool,
}

#[derive(Clone,Copy,PartialEq)]
pub struct ExpandFlags {
    pub files: bool,
    pub container: bool,
    pub releases: bool,
    pub creators: bool,
}

impl ExpandFlags {

    pub fn from_string(param: &str) -> ExpandFlags {
        let list: Vec<&str> = param.split_terminator(",").collect();
        ExpandFlags::from_strings(&list)
    }
    pub fn from_strings(list: &[&str]) -> ExpandFlags {
        if list.contains(&"none") {
            ExpandFlags::none()
        } else if list.contains(&"all") {
            ExpandFlags::all()
        } else {
            ExpandFlags {
                files: list.contains(&"files"),
                container: list.contains(&"container"),
                releases: list.contains(&"releases"),
                creators: list.contains(&"creators"),
            }
        }
    }
    pub fn all() -> ExpandFlags {
        ExpandFlags {
            files: true,
            container: true,
            releases: true,
            creators: true,
        }
    }
    pub fn none() -> ExpandFlags {
        ExpandFlags {
            files: false,
            container: false,
            releases: false,
            creators: false,
        }
    }
}

#[test]
fn test_expand_flags() {
    assert!(ExpandFlags::from_strings(&vec![]).files == false);
    assert!(ExpandFlags::from_strings(&vec!["files"]).files == true);
    assert!(ExpandFlags::from_strings(&vec!["file"]).files == false);
    let all = ExpandFlags::from_strings(&vec!["files", "container", "other_thing", "releases", "creators"]);
    assert!(all == ExpandFlags {
        files: true,
        container: true,
        releases: true,
        creators: true
    });
    assert!(ExpandFlags::from_string("").files == false);
    assert!(ExpandFlags::from_string("files").files == true);
    assert!(ExpandFlags::from_string("something,,files").files == true);
    assert!(ExpandFlags::from_string("file").files == false);
    let all = ExpandFlags::from_string("files,container,other_thing,releases,creators");
    assert!(all == ExpandFlags {
        files: true,
        container: true,
        releases: true,
        creators: true
    });
    assert!(all == ExpandFlags::all());
}

pub fn make_edit_context(
    conn: &DbConn,
    editgroup_id: Option<FatCatId>,
    autoaccept: bool,
) -> Result<EditContext> {
    let editor_id = Uuid::parse_str("00000000-0000-0000-AAAA-000000000001")?; // TODO: auth
    let editgroup_id: FatCatId = match (editgroup_id, autoaccept) {
        (Some(eg), _) => eg,
        // If autoaccept and no editgroup_id passed, always create a new one for this transaction
        (None, true) => {
            let eg_row: EditgroupRow = diesel::insert_into(editgroup::table)
                .values((editgroup::editor_id.eq(editor_id),))
                .get_result(conn)?;
            FatCatId::from_uuid(&eg_row.id)
        }
        (None, false) => FatCatId::from_uuid(&get_or_create_editgroup(editor_id, conn)?),
    };
    Ok(EditContext {
        editor_id: FatCatId::from_uuid(&editor_id),
        editgroup_id: editgroup_id,
        extra_json: None,
        autoaccept: autoaccept,
    })
}

/// This function should always be run within a transaction
pub fn get_or_create_editgroup(editor_id: Uuid, conn: &DbConn) -> Result<Uuid> {
    // check for current active
    let ed_row: EditorRow = editor::table.find(editor_id).first(conn)?;
    if let Some(current) = ed_row.active_editgroup_id {
        return Ok(current);
    }

    // need to insert and update
    let eg_row: EditgroupRow = diesel::insert_into(editgroup::table)
        .values((editgroup::editor_id.eq(ed_row.id),))
        .get_result(conn)?;
    diesel::update(editor::table.find(ed_row.id))
        .set(editor::active_editgroup_id.eq(eg_row.id))
        .execute(conn)?;
    Ok(eg_row.id)
}

/// This function should always be run within a transaction
pub fn accept_editgroup(editgroup_id: FatCatId, conn: &DbConn) -> Result<ChangelogRow> {
    // check that we haven't accepted already (in changelog)
    // NB: could leave this to a UNIQUE constraint
    let count: i64 = changelog::table
        .filter(changelog::editgroup_id.eq(editgroup_id.to_uuid()))
        .count()
        .get_result(conn)?;
    if count > 0 {
        return Err(ErrorKind::EditgroupAlreadyAccepted(editgroup_id.to_string()).into());
    }

    // copy edit columns to ident table
    ContainerEntity::db_accept_edits(conn, editgroup_id)?;
    CreatorEntity::db_accept_edits(conn, editgroup_id)?;
    FileEntity::db_accept_edits(conn, editgroup_id)?;
    ReleaseEntity::db_accept_edits(conn, editgroup_id)?;
    WorkEntity::db_accept_edits(conn, editgroup_id)?;

    // append log/changelog row
    let entry: ChangelogRow = diesel::insert_into(changelog::table)
        .values((changelog::editgroup_id.eq(editgroup_id.to_uuid()),))
        .get_result(conn)?;

    // update any editor's active editgroup
    let no_active: Option<Uuid> = None;
    diesel::update(editor::table)
        .filter(editor::active_editgroup_id.eq(editgroup_id.to_uuid()))
        .set(editor::active_editgroup_id.eq(no_active))
        .execute(conn)?;
    Ok(entry)
}

#[derive(Clone,Copy,PartialEq)]
pub struct FatCatId(Uuid);

impl ToString for FatCatId {
    fn to_string(&self) -> String {
        uuid2fcid(&self.to_uuid())
    }
}

impl FromStr for FatCatId {
    type Err = Error;
    fn from_str(s: &str) -> Result<FatCatId> {
        fcid2uuid(s).map(|u| FatCatId(u))
    }
}

impl FatCatId {
    pub fn to_uuid(&self) -> Uuid {
        self.0
    }
    // TODO: just make it u: Uuid and clone (not by ref)
    pub fn from_uuid(u: &Uuid) -> FatCatId {
        FatCatId(*u)
    }
}

/// Convert fatcat IDs (base32 strings) to UUID
pub fn fcid2uuid(fcid: &str) -> Result<Uuid> {
    if fcid.len() != 26 {
        return Err(ErrorKind::InvalidFatcatId(fcid.to_string()).into());
    }
    let mut raw = vec![0; 16];
    BASE32_NOPAD
        .decode_mut(fcid.to_uppercase().as_bytes(), &mut raw)
        .map_err(|_dp| ErrorKind::InvalidFatcatId(fcid.to_string()))?;
    // unwrap() is safe here, because we know raw is always 16 bytes
    Ok(Uuid::from_bytes(&raw).unwrap())
}

/// Convert UUID to fatcat ID string (base32 encoded)
pub fn uuid2fcid(id: &Uuid) -> String {
    let raw = id.as_bytes();
    BASE32_NOPAD.encode(raw).to_lowercase()
}

pub fn check_pmcid(raw: &str) -> Result<()> {
    lazy_static! {
        static ref RE: Regex = Regex::new(r"^PMC\d+$").unwrap();
    }
    if RE.is_match(raw) {
        Ok(())
    } else {
        Err(ErrorKind::MalformedExternalId(format!(
            "not a valid PubMed Central ID (PMCID): '{}' (expected, eg, 'PMC12345')",
            raw
        )).into())
    }
}

pub fn check_pmid(raw: &str) -> Result<()> {
    lazy_static! {
        static ref RE: Regex = Regex::new(r"^\d+$").unwrap();
    }
    if RE.is_match(raw) {
        Ok(())
    } else {
        Err(ErrorKind::MalformedExternalId(format!(
            "not a valid PubMed ID (PMID): '{}' (expected, eg, '1234')",
            raw
        )).into())
    }
}

pub fn check_wikidata_qid(raw: &str) -> Result<()> {
    lazy_static! {
        static ref RE: Regex = Regex::new(r"^Q\d+$").unwrap();
    }
    if RE.is_match(raw) {
        Ok(())
    } else {
        Err(ErrorKind::MalformedExternalId(format!(
            "not a valid Wikidata QID: '{}' (expected, eg, 'Q1234')",
            raw
        )).into())
    }
}

pub fn check_doi(raw: &str) -> Result<()> {
    lazy_static! {
        static ref RE: Regex = Regex::new(r"^10.\d{3,6}/.+$").unwrap();
    }
    if RE.is_match(raw) {
        Ok(())
    } else {
        Err(ErrorKind::MalformedExternalId(format!(
            "not a valid DOI: '{}' (expected, eg, '10.1234/aksjdfh')",
            raw
        )).into())
    }
}

pub fn check_issn(raw: &str) -> Result<()> {
    lazy_static! {
        static ref RE: Regex = Regex::new(r"^\d{4}-\d{3}[0-9X]$").unwrap();
    }
    if RE.is_match(raw) {
        Ok(())
    } else {
        Err(ErrorKind::MalformedExternalId(format!(
            "not a valid ISSN: '{}' (expected, eg, '1234-5678')",
            raw
        )).into())
    }
}

pub fn check_orcid(raw: &str) -> Result<()> {
    lazy_static! {
        static ref RE: Regex = Regex::new(r"^\d{4}-\d{4}-\d{4}-\d{3}[\dX]$").unwrap();
    }
    if RE.is_match(raw) {
        Ok(())
    } else {
        Err(ErrorKind::MalformedExternalId(format!(
            "not a valid ORCID: '{}' (expected, eg, '0123-4567-3456-6789')",
            raw
        )).into())
    }
}

#[test]
fn test_check_orcid() {
    assert!(check_orcid("0123-4567-3456-6789").is_ok());
    assert!(check_orcid("0123-4567-3456-678X").is_ok());
    assert!(check_orcid("01234567-3456-6780").is_err());
    assert!(check_orcid("0x23-4567-3456-6780").is_err());
}

// TODO: make the above checks "more correct"
// TODO: check ISBN-13
// TODO: check hashes (SHA-1, etc)