package api

import (
	"encoding/json"
	"fmt"
	"net/http"
	"strings"

	"arimelody.me/arimelody.me/global"
	"arimelody.me/arimelody.me/music/model"
)

type artistJSON struct {
    ID      string  `json:"id"`
    Name    *string `json:"name"`
    Website *string `json:"website"`
    Avatar  *string `json:"avatar"`
}

func ServeAllArtists() http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        var artists = []*model.Artist{}
        err := global.DB.Select(&artists, "SELECT * FROM artist")
		if err != nil {
            fmt.Printf("FATAL: Failed to serve all artists: %s\n", err)
			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
			return
		}

		w.Header().Add("Content-Type", "application/json")
        err = json.NewEncoder(w).Encode(artists)
		if err != nil {
			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		}
    })
}

func ServeArtist(artist model.Artist) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		type (
			creditJSON struct {
                Release string  `json:"release"`
				Role    string  `json:"role"`
				Primary bool    `json:"primary"`
			}
			artistJSON struct {
				model.Artist
				Credits map[string]creditJSON `json:"credits"`
			}
		)

        var credits = map[string]creditJSON{}
        err := global.DB.Select(&credits, "SELECT release,role,is_primary FROM musiccredit WHERE id=$1", artist.ID)
		if err != nil {
            fmt.Printf("FATAL: Failed to retrieve artist credits for %s: %s\n", artist.ID, err)
			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
			return
		}

		w.Header().Add("Content-Type", "application/json")
        err = json.NewEncoder(w).Encode(artistJSON{
            Artist: artist,
            Credits: credits,
        })
		if err != nil {
			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		}
	})
}

func CreateArtist() http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        var data artistJSON
        err := json.NewDecoder(r.Body).Decode(&data)
        if err != nil {
            http.Error(w, http.StatusText(http.StatusBadRequest), http.StatusBadRequest)
            return
        }

        if data.ID == "" {
            http.Error(w, "Artist ID cannot be blank\n", http.StatusBadRequest)
            return
        }
        if data.Name == nil || *data.Name == "" {
            http.Error(w, "Artist name cannot be blank\n", http.StatusBadRequest)
            return
        }

        var artist = model.Artist{
            ID: data.ID,
            Name: *data.Name,
            Website: *data.Website,
            Avatar: *data.Avatar,
        }

        _, err = global.DB.Exec(
		    "INSERT INTO artist (id, name, website, avatar) "+
            "VALUES ($1, $2, $3, $4)",
		    artist.ID,
		    artist.Name,
		    artist.Website,
            artist.Avatar)
        if err != nil {
            if strings.Contains(err.Error(), "duplicate key") {
                http.Error(w, fmt.Sprintf("Artist %s already exists\n", data.ID), http.StatusBadRequest)
                return
            }
            fmt.Printf("FATAL: Failed to create artist %s: %s\n", artist.ID, err)
            http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
            return
        }

        w.WriteHeader(http.StatusCreated)
    })
}

func UpdateArtist(artist model.Artist) http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        var data artistJSON
        err := json.NewDecoder(r.Body).Decode(&data)
        if err != nil {
            fmt.Printf("FATAL: Failed to update artist: %s\n", err)
            http.Error(w, http.StatusText(http.StatusBadRequest), http.StatusBadRequest)
            return
        }

        if data.ID != "" { artist.ID = data.ID }
        if data.Name != nil { artist.Name = *data.Name }
        if data.Website != nil { artist.Website = *data.Website }
        if data.Avatar != nil { artist.Avatar = *data.Avatar }

        _, err = global.DB.Exec(
            "UPDATE artist "+
            "SET name=$2, website=$3, avatar=$4 "+
            "WHERE id=$1",
            artist.ID,
            artist.Name,
            artist.Website,
            artist.Avatar)
        if err != nil {
            fmt.Printf("FATAL: Failed to update artist %s: %s\n", artist.ID, err)
            http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
        }
    })
}

func DeleteArtist(artist model.Artist) http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        _, err := global.DB.Exec(
            "DELETE FROM artist "+
            "WHERE id=$1",
            artist.ID)
        if err != nil {
            fmt.Printf("FATAL: Failed to delete artist %s: %s\n", artist.ID, err)
            http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
        }
    })
}