use crate::{EntityType, Specifier};
use anyhow::{anyhow, Context, Result};
use fatcat_openapi::models;
use lazy_static::lazy_static;
use log::{self, info};
use regex::Regex;
use std::io::{BufRead, Read};
use std::path::PathBuf;
use std::str::FromStr;

#[derive(Debug, PartialEq, Clone)]
pub struct Mutation {
    field: String,
    value: Option<String>,
}

impl FromStr for Mutation {
    type Err = anyhow::Error;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        // first try simple entity prefixes
        lazy_static! {
            static ref MUTATE_ENTITY_RE: Regex = Regex::new(r"^([a-z_]+)=(.*)$").unwrap();
        }
        if let Some(captures) = MUTATE_ENTITY_RE.captures(s) {
            return Ok(Mutation {
                field: captures[1].to_string(),
                value: match &captures[2] {
                    "" => None,
                    val => Some(val.to_string()),
                },
            });
        }
        Err(anyhow!("not a field mutation: {}", s))
    }
}

/*
 * Goal is to have traits around API entities. Things we'll want to do on concrete entities:
 *
 * - print, or pretty-print, as JSON or TOML
 * - get fcid (or, self-specifier)
 * - update (mutate or return copy) fields based on parameters
 * - update self to remote API
 *
 * Methods that might return trait objects:
 *
 * - get by specifier
 */

pub trait ApiEntityModel: ApiModelSer + ApiModelIdent + ApiModelMutate {}

impl ApiEntityModel for models::ReleaseEntity {}
impl ApiEntityModel for models::ContainerEntity {}
impl ApiEntityModel for models::CreatorEntity {}
impl ApiEntityModel for models::WorkEntity {}
impl ApiEntityModel for models::FileEntity {}
impl ApiEntityModel for models::FilesetEntity {}
impl ApiEntityModel for models::WebcaptureEntity {}
impl ApiEntityModel for models::Editor {}
impl ApiEntityModel for models::Editgroup {}
impl ApiEntityModel for models::ChangelogEntry {}

pub fn read_entity_file(input_path: Option<PathBuf>) -> Result<String> {
    // treat "-" as "use stdin"
    let input_path = match input_path {
        Some(s) if s.to_string_lossy() == "-" => None,
        _ => input_path,
    };
    match input_path {
        None => {
            let mut line = String::new();
            std::io::stdin().read_line(&mut line)?;
            Ok(line)
        }
        Some(path) if path.extension().map(|v| v.to_str()) == Some(Some("toml")) => {
            info!("reading {:?} as TOML", path);
            // as a hack, read TOML but then serialize it back to JSON
            let mut contents = String::new();
            let mut input_file =
                std::fs::File::open(path).context("reading entity from TOML file")?;
            input_file.read_to_string(&mut contents)?;
            let value: toml::Value = contents.parse().context("parsing TOML file")?;
            Ok(serde_json::to_string(&value)?)
        }
        Some(path) => {
            let mut line = String::new();
            let input_file = std::fs::File::open(path)?;
            let mut buffered = std::io::BufReader::new(input_file);
            buffered.read_line(&mut line)?;
            Ok(line)
        }
    }
}

pub fn entity_model_from_json_str(
    entity_type: EntityType,
    json_str: &str,
) -> Result<Box<dyn ApiEntityModel>> {
    match entity_type {
        EntityType::Release => Ok(Box::new(serde_json::from_str::<models::ReleaseEntity>(
            &json_str,
        )?)),
        EntityType::Work => Ok(Box::new(serde_json::from_str::<models::WorkEntity>(
            &json_str,
        )?)),
        EntityType::Container => Ok(Box::new(serde_json::from_str::<models::ContainerEntity>(
            &json_str,
        )?)),
        EntityType::Creator => Ok(Box::new(serde_json::from_str::<models::CreatorEntity>(
            &json_str,
        )?)),
        EntityType::File => Ok(Box::new(serde_json::from_str::<models::FileEntity>(
            &json_str,
        )?)),
        EntityType::FileSet => Ok(Box::new(serde_json::from_str::<models::FilesetEntity>(
            &json_str,
        )?)),
        EntityType::WebCapture => Ok(Box::new(serde_json::from_str::<models::WebcaptureEntity>(
            &json_str,
        )?)),
    }
}

pub trait ApiModelSer {
    fn to_json_string(&self) -> Result<String>;
    fn to_json_value(&self) -> Result<serde_json::Value>;
    fn to_toml_string(&self) -> Result<String>;
}

impl<T: serde::Serialize> ApiModelSer for T {
    fn to_json_string(&self) -> Result<String> {
        Ok(serde_json::to_string(self)?)
    }

    fn to_json_value(&self) -> Result<serde_json::Value> {
        Ok(serde_json::to_value(self)?)
    }

    fn to_toml_string(&self) -> Result<String> {
        Ok(toml::Value::try_from(self)?.to_string())
    }
}

pub trait ApiModelIdent {
    fn specifier(&self) -> Specifier;
}

macro_rules! generic_entity_specifier {
    ($specifier_type:ident) => {
        fn specifier(&self) -> Specifier {
            if let Some(fcid) = &self.ident {
                Specifier::$specifier_type(fcid.to_string())
            } else {
                panic!("expected full entity")
            }
        }
    };
}

impl ApiModelIdent for models::ReleaseEntity {
    generic_entity_specifier!(Release);
}
impl ApiModelIdent for models::ContainerEntity {
    generic_entity_specifier!(Container);
}
impl ApiModelIdent for models::CreatorEntity {
    generic_entity_specifier!(Creator);
}
impl ApiModelIdent for models::WorkEntity {
    generic_entity_specifier!(Work);
}
impl ApiModelIdent for models::FileEntity {
    generic_entity_specifier!(File);
}
impl ApiModelIdent for models::FilesetEntity {
    generic_entity_specifier!(FileSet);
}
impl ApiModelIdent for models::WebcaptureEntity {
    generic_entity_specifier!(WebCapture);
}

impl ApiModelIdent for models::ChangelogEntry {
    fn specifier(&self) -> Specifier {
        Specifier::Changelog(self.index)
    }
}

impl ApiModelIdent for models::Editgroup {
    fn specifier(&self) -> Specifier {
        if let Some(fcid) = &self.editgroup_id {
            Specifier::Editgroup(fcid.to_string())
        } else {
            panic!("expected full entity")
        }
    }
}

impl ApiModelIdent for models::Editor {
    fn specifier(&self) -> Specifier {
        if let Some(fcid) = &self.editor_id {
            Specifier::Editor(fcid.to_string())
        } else {
            panic!("expected full entity")
        }
    }
}

pub trait ApiModelMutate {
    fn mutate(&mut self, mutations: Vec<Mutation>) -> Result<()>;
}

impl ApiModelMutate for models::ReleaseEntity {
    fn mutate(&mut self, mutations: Vec<Mutation>) -> Result<()> {
        for m in mutations {
            match (m.field.as_str(), m.value) {
                ("title", val) => {
                    self.title = val;
                }
                ("subtitle", val) => {
                    self.subtitle = val;
                }
                ("original_title", val) => {
                    self.original_title = val;
                }
                ("container_id", val) => {
                    self.container_id = val;
                }
                ("work_id", val) => {
                    self.work_id = val;
                }
                ("release_type", val) => {
                    self.release_type = val;
                }
                ("release_stage", val) => {
                    self.release_stage = val;
                }
                ("withdrawn_status", val) => {
                    self.withdrawn_status = val;
                }
                ("license_slug", val) => {
                    self.license_slug = val;
                }
                ("volume", val) => {
                    self.volume = val;
                }
                ("issue", val) => {
                    self.issue = val;
                }
                ("number", val) => {
                    self.number = val;
                }
                ("publisher", val) => {
                    self.publisher = val;
                }
                ("language", val) => {
                    self.language = val;
                }
                // None-only fields, for now
                ("release_date", None) => {
                    self.release_date = None;
                }
                ("release_year", None) => {
                    self.release_year = None;
                }
                (field, _) => unimplemented!("setting field {} on a release", field),
            }
        }
        Ok(())
    }
}

impl ApiModelMutate for models::ContainerEntity {
    fn mutate(&mut self, mutations: Vec<Mutation>) -> Result<()> {
        for m in mutations {
            match (m.field.as_str(), m.value) {
                ("name", val) => {
                    self.name = val;
                }
                ("container_type", val) => {
                    self.container_type = val;
                }
                ("publisher", val) => {
                    self.publisher = val;
                }
                ("issnl", val) => {
                    self.issnl = val;
                }
                ("issne", val) => {
                    self.issne = val;
                }
                ("issnp", val) => {
                    self.issnp = val;
                }
                ("publication_status", val) => {
                    self.publication_status = val;
                }
                (field, _) => unimplemented!("setting field {} on a container", field),
            }
        }
        Ok(())
    }
}

impl ApiModelMutate for models::CreatorEntity {
    fn mutate(&mut self, mutations: Vec<Mutation>) -> Result<()> {
        for m in mutations {
            match (m.field.as_str(), m.value) {
                ("display_name", val) => {
                    self.display_name = val;
                }
                ("given_name", val) => {
                    self.given_name = val;
                }
                ("surname", val) => {
                    self.surname = val;
                }
                (field, _) => unimplemented!("setting field {} on a creator", field),
            }
        }
        Ok(())
    }
}

impl ApiModelMutate for models::WorkEntity {
    fn mutate(&mut self, _mutations: Vec<Mutation>) -> Result<()> {
        unimplemented!("mutations")
    }
}

impl ApiModelMutate for models::FileEntity {
    fn mutate(&mut self, mutations: Vec<Mutation>) -> Result<()> {
        for m in mutations {
            match (m.field.as_str(), m.value) {
                ("size", Some(val)) => {
                    self.size = Some(i64::from_str(&val)?);
                }
                ("size", None) => {
                    self.size = None;
                }
                ("md5", val) => {
                    self.md5 = val;
                }
                ("sha1", val) => {
                    self.sha1 = val;
                }
                ("sha256", val) => {
                    self.sha256 = val;
                }
                ("mimetype", val) => {
                    self.mimetype = val;
                }
                ("release_ids", None) => {
                    self.release_ids = None;
                }
                ("content_scope", val) => {
                    self.content_scope = val;
                }
                (field, _) => unimplemented!("setting field {} on a file", field),
            }
        }
        Ok(())
    }
}

impl ApiModelMutate for models::FilesetEntity {
    fn mutate(&mut self, mutations: Vec<Mutation>) -> Result<()> {
        for m in mutations {
            match (m.field.as_str(), m.value) {
                ("release_ids", None) => {
                    self.release_ids = None;
                }
                ("content_scope", val) => {
                    self.content_scope = val;
                }
                (field, _) => unimplemented!("setting field {} on a fileset", field),
            }
        }
        Ok(())
    }
}

impl ApiModelMutate for models::WebcaptureEntity {
    fn mutate(&mut self, mutations: Vec<Mutation>) -> Result<()> {
        for m in mutations {
            match (m.field.as_str(), m.value) {
                ("release_ids", None) => {
                    self.release_ids = None;
                }
                ("content_scope", val) => {
                    self.content_scope = val;
                }
                (field, _) => unimplemented!("setting field {} on a webcapture", field),
            }
        }
        Ok(())
    }
}

impl ApiModelMutate for models::Editor {
    fn mutate(&mut self, mutations: Vec<Mutation>) -> Result<()> {
        for m in mutations {
            match (m.field.as_str(), m.value) {
                ("username", Some(val)) => {
                    self.username = val;
                }
                (field, _) => unimplemented!("setting field {} on an editor", field),
            }
        }
        Ok(())
    }
}

impl ApiModelMutate for models::Editgroup {
    fn mutate(&mut self, mutations: Vec<Mutation>) -> Result<()> {
        for m in mutations {
            match (m.field.as_str(), m.value) {
                ("description", val) => {
                    self.description = val;
                }
                (field, _) => unimplemented!("setting field {} on an editgroup", field),
            }
        }
        Ok(())
    }
}

impl ApiModelMutate for models::ChangelogEntry {
    fn mutate(&mut self, _mutations: Vec<Mutation>) -> Result<()> {
        unimplemented!("mutations")
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_mutation_from_str() -> () {
        assert!(Mutation::from_str("release_asdf").is_err());
        assert_eq!(
            Mutation::from_str("title=blah").unwrap(),
            Mutation {
                field: "title".to_string(),
                value: Some("blah".to_string())
            }
        );
        assert_eq!(
            Mutation::from_str("title=").unwrap(),
            Mutation {
                field: "title".to_string(),
                value: None
            }
        );
        assert_eq!(
            Mutation::from_str("title=string with spaces and stuff").unwrap(),
            Mutation {
                field: "title".to_string(),
                value: Some("string with spaces and stuff".to_string())
            }
        );
    }
}