package storage

import (
	"database/sql"
	"errors"
	"fmt"
	"io"
	"log"
	"mime/multipart"
	"os"
	"path"
	"strings"
	"time"

	"git.aetherial.dev/aeth/keiji/pkg/env"
	"github.com/google/uuid"
)

const TECHNICAL = "technical"
const CONFIGURATION = "configuration"
const BLOG = "blog"
const CREATIVE = "creative"
const DIGITAL_ART = "digital_art"
const HOMEPAGE = "homepage"

var Topics = []string{
	TECHNICAL,
	BLOG,
	CREATIVE,
	HOMEPAGE,
}

type DatabaseSchema struct {
	// Gotta figure out what this looks like
	// so that the ExtractAll() function gets
	// all of the data from the database

}

type MenuElement struct {
	Png       string     `json:"png"`
	Category  string     `json:"category"`
	MenuLinks []LinkPair `json:"menu_links"`
}
type AdminPage struct {
	Tables map[string][]TableData `json:"tables"`
}

type TableData struct { // TODO: add this to the database io interface
	DisplayName string `json:"display_name"`
	Link        string `json:"link"`
}

type LinkPair struct {
	Link string `json:"link"`
	Text string `json:"text"`
}

type NavBarItem struct {
	Png      []byte `json:"png"`
	Link     string `json:"link"`
	Redirect string `json:"redirect"`
}

type Asset struct {
	Name string
	Data []byte
}

type Identifier string

type Document struct {
	Row      int
	Ident    Identifier `json:"id"`
	Title    string     `json:"title"`
	Created  string     `json:"created"`
	Body     string     `json:"body"`
	Category string     `json:"category"`
	Sample   string     `json:"sample"`
}

/*
Truncates a text post into a 256 character long 'sample' for displaying posts
*/
func (d *Document) MakeSample() string {
	t := strings.Split(d.Body, "")
	var sample []string
	if len(d.Body) < 256 {
		return d.Body
	}
	for i := 0; i < 256; i++ {
		sample = append(sample, t[i])
	}
	sample = append(sample, " ...")
	return strings.Join(sample, "")

}

type Image struct {
	Ident    Identifier `json:"identifier"`
	Location string
	Title    string                `json:"title" form:"title"`
	File     *multipart.FileHeader `form:"file"`
	Desc     string                `json:"description" form:"description"`
	Created  string
	Category string
	Data     []byte
}

type DocumentIO interface {
	GetDocument(id Identifier) (Document, error)
	GetImage(id Identifier) (Image, error)
	GetAllImages() []Image
	UpdateDocument(doc Document) error
	DeleteDocument(id Identifier) error
	AddDocument(doc Document) (Identifier, error)
	AddImage(data []byte, title, desc string) (Identifier, error)
	AddAsset(name string, data []byte) error
	AddAdminTableEntry(TableData, string) error
	AddNavbarItem(NavBarItem) error
	AddMenuItem(LinkPair) error
	GetByCategory(category string) []Document
	AllDocuments() []Document
	GetDropdownElements() []LinkPair
	GetNavBarLinks() []NavBarItem
	GetAssets() []Asset
	GetAdminTables() AdminPage
}

var (
	ErrDuplicate    = errors.New("record already exists")
	ErrNotExists    = errors.New("row not exists")
	ErrUpdateFailed = errors.New("update failed")
	ErrDeleteFailed = errors.New("delete failed")
)

type SQLiteRepo struct {
	db      *sql.DB
	imageIO ImageIO
}

type ImageIO interface {
	Put([]byte, Identifier) error
	Get(Identifier) ([]byte, error)
}

type FilesystemImageIO struct {
	RootDir string
}

/*
Put a data blob on the filesystem

	:param b: the
*/
func (f FilesystemImageIO) Put(b []byte, id Identifier) error {
	fh, err := os.OpenFile(path.Join(f.RootDir, string(id)), os.O_CREATE|os.O_RDWR, os.ModePerm)
	if err != nil {
		return err
	}
	defer fh.Close()
	_, err = fh.Write(b)
	if err != nil {
		return err
	}
	return nil
}

/*
Get a data blob from the filesystem

	:param id: the identifier of the image to retrieve
*/
func (f FilesystemImageIO) Get(id Identifier) ([]byte, error) {
	fh, err := os.Open(path.Join(f.RootDir, string(id)))
	if err != nil {
		return nil, err
	}
	b, err := io.ReadAll(fh)
	if err != nil {
		return nil, err
	}
	return b, nil
}

// Instantiate a new SQLiteRepo struct
func NewSQLiteRepo(db *sql.DB, imgIo ImageIO) *SQLiteRepo {
	return &SQLiteRepo{
		db:      db,
		imageIO: imgIo,
	}

}

// Creates a new SQL table for text posts
func (r *SQLiteRepo) Migrate(seedQueries []string) error {
	for i := range seedQueries {
		_, err := r.db.Exec(seedQueries[i])
		if err != nil {
			return err
		}
	}
	return nil
}

/*
Get all dropdown menu elements. Returns a list of LinkPair structs with the text and redirect location
*/
func (s *SQLiteRepo) GetDropdownElements() []LinkPair {
	rows, err := s.db.Query("SELECT * FROM menu")
	var menuItems []LinkPair
	defer rows.Close()
	for rows.Next() {
		var id int
		var item LinkPair
		err = rows.Scan(&id, &item.Link, &item.Text)
		if err != nil {
			log.Fatal(err)
		}
		menuItems = append(menuItems, item)
	}
	return menuItems

}

/*
Get all nav bar items. Returns a list of NavBarItem structs with the png data, the file name, and the redirect location of the icon
*/
func (s *SQLiteRepo) GetNavBarLinks() []NavBarItem {

	rows, err := s.db.Query("SELECT * FROM navbar")
	var navbarItems []NavBarItem
	defer rows.Close()
	for rows.Next() {
		var item NavBarItem
		var id int
		err = rows.Scan(&id, &item.Png, &item.Link, &item.Redirect)
		if err != nil {
			log.Fatal(err)
		}
		navbarItems = append(navbarItems, item)
	}
	return navbarItems

}

/*
get all assets from the asset table
*/
func (s *SQLiteRepo) GetAssets() []Asset {
	rows, err := s.db.Query("SELECT * FROM assets")
	var assets []Asset
	defer rows.Close()
	for rows.Next() {
		var item Asset
		var id int
		err = rows.Scan(&id, &item.Name, &item.Data)
		if err != nil {
			log.Fatal(err)
		}
		assets = append(assets, item)
	}
	return assets

}

/*
get all assets from the asset table
*/
func (s *SQLiteRepo) GetAdminTables() AdminPage {
	rows, err := s.db.Query("SELECT * FROM admin")
	adminPage := AdminPage{Tables: map[string][]TableData{}}
	defer rows.Close()
	for rows.Next() {
		var item TableData
		var id int
		var category string
		err = rows.Scan(&id, &item.DisplayName, &item.Link, &category)
		if err != nil {
			log.Fatal(err)
		}
		adminPage.Tables[category] = append(adminPage.Tables[category], item)
	}
	return adminPage

}

/*
Retrieve a document from the sqlite db

	:param id: the Identifier of the post
*/
func (s *SQLiteRepo) GetDocument(id Identifier) (Document, error) {
	row := s.db.QueryRow("SELECT * FROM posts WHERE id = ?", id)

	var post Document
	var rowNum int
	if err := row.Scan(&rowNum, &post.Ident, &post.Title, &post.Created, &post.Body, &post.Category, &post.Sample); err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			return post, ErrNotExists
		}
		return post, err
	}
	return post, nil

}

/*
Get all documents by category

	:param category: the category to retrieve all docs from
*/
func (s *SQLiteRepo) GetByCategory(category string) []Document {
	rows, err := s.db.Query("SELECT * FROM posts WHERE category = ?", category)
	if err != nil {
		log.Fatal(err)
	}
	var docs []Document
	defer rows.Close()
	for rows.Next() {
		var doc Document
		err := rows.Scan(&doc.Row, &doc.Ident, &doc.Title, &doc.Created, &doc.Body, &doc.Category, &doc.Sample)
		if err != nil {
			log.Fatal(err)
		}
		docs = append(docs, doc)
	}
	err = rows.Err()
	if err != nil {
		log.Fatal(err)
	}
	return docs

}

/*
get image data from the images table

	:param id: the serial identifier of the post
*/
func (s *SQLiteRepo) GetImage(id Identifier) (Image, error) {
	row := s.db.QueryRow("SELECT * FROM images WHERE id = ?", id)
	var rowNum int
	var title, desc, created string
	if err := row.Scan(&rowNum, &id, &title, &desc, &created); err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			return Image{}, ErrNotExists
		}
		return Image{}, err
	}
	data, err := s.imageIO.Get(id)
	if err != nil {
		return Image{}, err
	}
	return Image{Ident: id, Title: title, Desc: desc, Data: data, Created: created}, nil
}

/*
Get all of the images from the datastore
*/
func (s *SQLiteRepo) GetAllImages() []Image {
	rows, err := s.db.Query("SELECT * FROM images")
	if err != nil {
		log.Fatal(err)
	}
	imgs := []Image{}
	for rows.Next() {
		var img Image
		var rowNum int
		err := rows.Scan(&rowNum, &img.Ident, &img.Title, &img.Desc, &img.Created)
		if err != nil {
			log.Fatal(err)
		}
		b, err := s.imageIO.Get(img.Ident)
		if err != nil {
			log.Fatal(err)
		}
		imgs = append(imgs, Image{Ident: img.Ident, Title: img.Title, Desc: img.Desc, Data: b, Created: img.Created})
	}
	err = rows.Err()
	if err != nil {
		log.Fatal(err)
	}
	return imgs
}

/*
Add an image to the database

	:param title: the title of the image
	:param location: the location to save the image to
	:param desc: the description of the image, if any
	:param data: the binary data for the image
*/
func (s *SQLiteRepo) AddImage(data []byte, title string, desc string) (Identifier, error) {
	id := newIdentifier()
	err := s.imageIO.Put(data, id)
	if err != nil {
		return Identifier(""), err
	}
	_, err = s.db.Exec("INSERT INTO images (id, title, desc, created) VALUES (?,?,?,?)", string(id), title, desc, time.Now().String())
	if err != nil {
		return Identifier(""), err
	}
	return id, nil
}

/*
Updates a document in the database with the supplied. Only changes the title, the body, category. Keys off of the documents Identifier

	:param doc: the Document to upload into the database
*/
func (s *SQLiteRepo) UpdateDocument(doc Document) error {
	tx, err := s.db.Begin()
	if err != nil {
		return err
	}
	stmt, err := tx.Prepare("UPDATE posts SET title = ?, body = ?, category = ?, sample = ? WHERE id = ?;")
	if err != nil {
		tx.Rollback()
		return err
	}

	res, err := stmt.Exec(doc.Title, doc.Body, doc.Category, doc.MakeSample(), doc.Ident)
	if err != nil {
		tx.Rollback()
		return err
	}
	affected, _ := res.RowsAffected()
	if affected != 1 {
		return ErrNotExists
	}

	tx.Commit()
	return nil
}

/*
Adds a LinkPair to the menu database table

	:param item: the LinkPair to upload
*/
func (s *SQLiteRepo) AddMenuItem(item LinkPair) error {
	tx, err := s.db.Begin()
	if err != nil {
		return err
	}
	stmt, _ := tx.Prepare("INSERT INTO menu(link, text) VALUES (?,?)")
	_, err = stmt.Exec(item.Link, item.Text)
	if err != nil {
		tx.Rollback()
		return err
	}
	tx.Commit()
	return nil

}

/*
Adds an item to the navbar database table

	:param item: the NavBarItem to upload
*/
func (s *SQLiteRepo) AddNavbarItem(item NavBarItem) error {
	tx, err := s.db.Begin()
	if err != nil {
		return err
	}
	stmt, err := tx.Prepare("INSERT INTO navbar(png, link, redirect) VALUES (?,?,?)")
	if err != nil {
		tx.Rollback()
		return err
	}
	_, err = stmt.Exec(item.Png, item.Link, item.Redirect)
	if err != nil {
		tx.Rollback()
		return err
	}
	tx.Commit()
	return nil

}

/*
Adds an asset to the asset database table asset

	:param name: the name of the asset (filename)
	:param data: the byte array of the PNG to upload TODO: limit this to 256kb
*/
func (s *SQLiteRepo) AddAsset(name string, data []byte) error {
	tx, err := s.db.Begin()
	if err != nil {
		return err
	}
	stmt, _ := tx.Prepare("INSERT INTO assets(name, data) VALUES (?,?)")
	_, err = stmt.Exec(name, data)
	if err != nil {
		tx.Rollback()
		return err
	}
	tx.Commit()
	return nil
}

/*
Adds a document to the database (for text posts)

	:param doc: the Document to add
*/
func (s *SQLiteRepo) AddDocument(doc Document) (Identifier, error) {
	id := newIdentifier()
	tx, err := s.db.Begin()
	if err != nil {
		return Identifier(""), err
	}
	stmt, _ := tx.Prepare("INSERT INTO posts(id, title, created, body, category, sample) VALUES (?,?,?,?,?,?)")
	_, err = stmt.Exec(id, doc.Title, doc.Created, doc.Body, doc.Category, doc.MakeSample())
	if err != nil {
		tx.Rollback()
		return Identifier(""), err
	}
	tx.Commit()
	return id, nil

}

/*
Add an entry to the 'admin' table in the database

	:param item: an admin table k/v text to redirect pair
	:param tableName: the name of the table to populate the link in on the UI
*/
func (s *SQLiteRepo) AddAdminTableEntry(item TableData, category string) error {
	tx, err := s.db.Begin()
	if err != nil {
		return err
	}
	stmt, _ := tx.Prepare("INSERT INTO admin (display_name, link, category) VALUES (?,?,?)")
	_, err = stmt.Exec(item.DisplayName, item.Link, category)
	if err != nil {
		tx.Rollback()
		return err
	}
	tx.Commit()

	return nil
}

/*
Delete a document from the db

	:param id: the identifier of the document to remove
*/
func (s *SQLiteRepo) DeleteDocument(id Identifier) error {
	tx, err := s.db.Begin()
	if err != nil {
		return err
	}
	stmt, _ := tx.Prepare("DELETE FROM posts WHERE id=?")
	_, err = stmt.Exec(id)
	if err != nil {
		tx.Rollback()
		return err
	}
	tx.Commit()
	return nil

}

// Get all Hosts from the host table
func (s *SQLiteRepo) AllDocuments() []Document {
	rows, err := s.db.Query("SELECT * FROM posts")
	if err != nil {
		fmt.Printf("There was an issue getting all posts. %s", err.Error())
		return nil
	}
	defer rows.Close()

	all := []Document{}
	for rows.Next() {
		var post Document
		if err := rows.Scan(&post.Row, &post.Ident, &post.Title, &post.Created, &post.Body, &post.Category, &post.Sample); err != nil {
			fmt.Printf("There was an error getting all documents. %s", err.Error())
			return nil
		}
		all = append(all, post)
	}
	return all
}

type InvalidSkipArg struct{ Skip int }

func (i *InvalidSkipArg) Error() string {
	return fmt.Sprintf("Invalid skip amount was passed: %v", i.Skip)
}

type ImageStoreItem struct {
	Identifier   string `json:"identifier"`
	Filename     string `json:"filename"`
	AbsolutePath string `json:"absolute_path"`
	Title        string `json:"title" form:"title"`
	Created      string `json:"created"`
	Desc         string `json:"description" form:"description"`
	Category     string `json:"category"`
	ApiPath      string
}

/*
Function to return the location of the image store. Wrapping the env call in
a function so that refactoring is easier
*/
func GetImageStore() string {
	return os.Getenv(env.IMAGE_STORE)
}

// Wrapping the new id call in a function to make refactoring easier
func newIdentifier() Identifier {
	return Identifier(uuid.NewString())
}