use std::{collections::HashSet, fmt::Debug, };

use chrono::{DateTime, Utc};
use serde::{Deserialize, Serialize};
use uuid::Uuid;


pub mod bandcamp;
pub mod mixxx;
pub mod beets;
pub mod musicbrainz;
pub mod archive;
pub mod tools;

#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub enum SourceID {
    Bandcamp,
    Musicbrainz,
    Mixxx,
    Beets
}

#[derive(Debug, Serialize, Deserialize, Clone, Default)]
pub struct Artist {
    pub name: String,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub bio: Option<String>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub location: Option<String>,
}

impl PartialEq for Artist {
    fn eq(&self, other: &Self) -> bool {
        if self.name != other.name {
            return false;
        }

        true
    }

    fn ne(&self, other: &Self) -> bool {
        !self.eq(other)
    }
}

#[derive(Debug, Serialize, Deserialize, Clone, Default)]
pub struct Album {
    pub title: String,
    pub artist: String,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub about: Option<String>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub credits: Option<String>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub release_date: Option<DateTime<Utc>>
}

impl PartialEq for Album {
    fn eq(&self, other: &Self) -> bool {
        if self.title != other.title || self.artist != other.artist {
            return false;
        }

        true
    }

    fn ne(&self, other: &Self) -> bool {
        !self.eq(other)
    }
}

#[derive(Debug, Serialize, Deserialize, Clone, Default)]
pub struct Track {
    pub title: String,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub label: Option<String>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub year: Option<u32>,
    #[serde(skip_serializing_if = "Vec::is_empty")]
    #[serde(default)]
    pub genres: Vec<String>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub album: Option<String>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub artist: Option<String>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub bpm: Option<f64>
}

impl PartialEq for Track {
    fn eq(&self, other: &Self) -> bool {
        if self.title != other.title {
            return false;
        }

        if other.artist.is_some() && self.artist.is_some() && self.artist != other.artist {
            return false;
        }

        if other.album.is_some() && self.album.is_some() && self.album != other.album {
            return false;
        }

        true
    }

    fn ne(&self, other: &Self) -> bool {
        !self.eq(other)
    }
}

#[derive(Clone, Debug, Deserialize, Serialize, PartialEq)]
#[serde(tag = "type")]
pub enum Contents {
    Artist(Artist),
    Album(Album),
    Track(Track)
}

impl From<Artist> for Contents {
    fn from(value: Artist) -> Self {
        Self::Artist(value)
    }
}

impl From<Album> for Contents {
    fn from(value: Album) -> Self {
        Self::Album(value)
    }
}

impl From<Track> for Contents {
    fn from(value: Track) -> Self {
        Self::Track(value)
    }
}

impl<M: Merge + PartialEq> Merge for Vec<M> {
    fn merge(&mut self, other: Self) {
        for artifact in other {
            if let Some(merge_target) = self.iter_mut().find(|a| { **a == artifact }) {
                merge_target.merge(artifact);
            } else {
                self.push(artifact);
            }
        }
    }
}

pub trait Merge {
    fn merge(&mut self, other: Self);
}

#[derive(Clone, Debug, Deserialize, Serialize, PartialEq)]
pub struct Artifact {
    #[serde(skip_serializing_if = "Option::is_none")]
    mbid: Option<Uuid>,
    #[serde(flatten)]
    contents: Contents,

    sources: HashSet<SourceID>,
}

#[derive(Debug)]
pub struct ArtifactBuilder {
    contents: Option<Contents>,
    mbid: Option<Uuid>,
    source: SourceID,
}

impl ArtifactBuilder {
    pub fn new(source: SourceID) -> Self {
        Self {
            contents: None,
            mbid: None,
            source,
        }
    }

    pub fn contents<T: Into<Contents>>(mut self, contents: T) -> Self {
        self.contents = Some(contents.into());
        self
    }

    pub fn mbid<T: Into<Uuid>>(mut self, mbid: T) -> Self {
        self.mbid = Some(mbid.into());
        self
    }

    pub fn build(self) -> Artifact {
        Artifact {
            mbid: self.mbid,
            contents: self.contents.unwrap(),
            sources: HashSet::from_iter([self.source]),
        }
    }
}

impl Artifact {
    pub fn contents(&self) -> &Contents {
        &self.contents
    }
}

impl Merge for Artifact {
    fn merge(&mut self, other: Self) {
        self.contents.merge(other.contents);
        if self.mbid.is_none() {
            self.mbid = other.mbid;
        }
        for src in other.sources {
            self.sources.insert(src);
        }
    }
}

macro_rules! merge_fields {
    ($this:expr, $that:expr, $field:tt) => {
        if $this.$field.is_none() {
            $this.$field = $that.$field;
        }
    };
    ($this:tt, $that:tt, $($fields:tt),+) => {
        $(
            merge_fields!($this, $that, $fields);
        )+
    }
}

impl Merge for Contents {
    fn merge(&mut self, other: Self) {
        if *self != other {
            return;
        }

        match (self, other) {
            (Self::Track(this_track), Self::Track(that_track)) => {
                this_track.merge(that_track);
            },
            (Self::Album(this_album), Self::Album(that_album)) => {
                this_album.merge(that_album);
            },
            (Self::Artist(this_artist), Self::Artist(that_artist)) => {
                this_artist.merge(that_artist);
            },
            _ => ()
        }
    }
}

impl Merge for Track {
    fn merge(&mut self, other: Self) {
        merge_fields!(self, other, album, label, year, artist, bpm);
    }
}

impl Merge for Artist {
    fn merge(&mut self, other: Self) {
        merge_fields!(self, other, bio, location);
    }
}

impl Merge for Album {
    fn merge(&mut self, other: Self) {
        merge_fields!(self, other, about, credits, release_date);
    }
}