package db

import (
	"database/sql"
	"errors"
	"log"
	"net/mail"
	"os"
	"time"

	"github.com/coopernurse/gorp"
	"github.com/jordan-wright/gophish/config"
	"github.com/jordan-wright/gophish/models"
	_ "github.com/mattn/go-sqlite3"
)

var Conn *gorp.DbMap
var DB *sql.DB
var err error
var ErrUsernameTaken = errors.New("Username already taken")
var Logger = log.New(os.Stdout, "", log.Ldate|log.Ltime|log.Lshortfile)

// Setup initializes the Conn object
// It also populates the Gophish Config object
func Setup() error {
	DB, err := sql.Open("sqlite3", config.Conf.DBPath)
	Conn = &gorp.DbMap{Db: DB, Dialect: gorp.SqliteDialect{}}
	//If the file already exists, delete it and recreate it
	_, err = os.Stat(config.Conf.DBPath)
	Conn.AddTableWithName(models.User{}, "users").SetKeys(true, "Id")
	Conn.AddTableWithName(models.Campaign{}, "campaigns").SetKeys(true, "Id")
	Conn.AddTableWithName(models.Group{}, "groups").SetKeys(true, "Id")
	if err != nil {
		Logger.Println("Database not found, recreating...")
		createTablesSQL := []string{
			//Create tables
			`CREATE TABLE users (id INTEGER PRIMARY KEY AUTOINCREMENT, username TEXT NOT NULL, hash VARCHAR(60) NOT NULL, api_key VARCHAR(32), UNIQUE(username), UNIQUE(api_key));`,
			`CREATE TABLE campaigns (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, created_date TIMESTAMP NOT NULL, completed_date TIMESTAMP, template TEXT, status TEXT NOT NULL, uid INTEGER, FOREIGN KEY (uid) REFERENCES users(id));`,
			`CREATE TABLE targets (id INTEGER PRIMARY KEY AUTOINCREMENT, email TEXT NOT NULL, UNIQUE(email));`,
			`CREATE TABLE groups (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, modified_date TIMESTAMP NOT NULL);`,
			`CREATE TABLE campaign_results (cid INTEGER NOT NULL, tid INTEGER NOT NULL, result TEXT NOT NULL, FOREIGN KEY (cid) REFERENCES users(id), FOREIGN KEY (tid) REFERENCES targets(id), UNIQUE(cid, tid))`,
			`CREATE TABLE user_groups (uid INTEGER NOT NULL, gid INTEGER NOT NULL, FOREIGN KEY (uid) REFERENCES users(id), FOREIGN KEY (gid) REFERENCES groups(id), UNIQUE(uid, gid))`,
			`CREATE TABLE group_targets (gid INTEGER NOT NULL, tid INTEGER NOT NULL, FOREIGN KEY (gid) REFERENCES groups(id), FOREIGN KEY (tid) REFERENCES targets(id), UNIQUE(gid, tid));`,
		}
		Logger.Printf("Creating db at %s\n", config.Conf.DBPath)
		//Create the tables needed
		for _, stmt := range createTablesSQL {
			_, err = DB.Exec(stmt)
			if err != nil {
				return err
			}
		}
		//Create the default user
		init_user := models.User{
			Username: "admin",
			Hash:     "$2a$10$IYkPp0.QsM81lYYPrQx6W.U6oQGw7wMpozrKhKAHUBVL4mkm/EvAS",
			APIKey:   "12345678901234567890123456789012",
		}
		Conn.Insert(&init_user)
		if err != nil {
			Logger.Println(err)
		}
		c := models.Campaign{
			Name:          "Test Campaigns",
			CreatedDate:   time.Now().UTC(),
			CompletedDate: time.Now().UTC(),
			Template:      "test template",
			Status:        "In progress",
			Uid:           init_user.Id,
		}
		Conn.Insert(&c)
	}
	return nil
}

// API Functions (GET, POST, PUT, DELETE)

// GetUser returns the user that the given id corresponds to. If no user is found, an
// error is thrown.
func GetUser(id int64) (models.User, error) {
	u := models.User{}
	err := Conn.SelectOne(&u, "SELECT * FROM Users WHERE id=?", id)
	if err != nil {
		return u, err
	}
	return u, nil
}

// GetUserByAPIKey returns the user that the given API Key corresponds to. If no user is found, an
// error is thrown.
func GetUserByAPIKey(key []byte) (models.User, error) {
	u := models.User{}
	err := Conn.SelectOne(&u, "SELECT id, username, api_key FROM Users WHERE apikey=?", key)
	if err != nil {
		return u, err
	}
	return u, nil
}

// GetUserByUsername returns the user that the given username corresponds to. If no user is found, an
// error is thrown.
func GetUserByUsername(username string) (models.User, error) {
	u := models.User{}
	err := Conn.SelectOne(&u, "SELECT * FROM Users WHERE username=?", username)
	if err != sql.ErrNoRows {
		return u, ErrUsernameTaken
	} else if err != nil {
		return u, err
	}
	return u, nil
}

// PutUser updates the given user
func PutUser(u *models.User) error {
	_, err := Conn.Update(u)
	return err
}

// GetCampaigns returns the campaigns owned by the given user.
func GetCampaigns(uid int64) ([]models.Campaign, error) {
	cs := []models.Campaign{}
	_, err := Conn.Select(&cs, "SELECT c.id, name, created_date, completed_date, status, template FROM campaigns c, users u WHERE c.uid=u.id AND u.id=?", uid)
	return cs, err
}

// GetCampaign returns the campaign, if it exists, specified by the given id and user_id.
func GetCampaign(id int64, uid int64) (models.Campaign, error) {
	c := models.Campaign{}
	err := Conn.SelectOne(&c, "SELECT c.id, name, created_date, completed_date, status, template FROM campaigns c, users u WHERE c.uid=u.id AND c.id =? AND u.id=?", id, uid)
	return c, err
}

// GetGroups returns the groups owned by the given user.
func GetGroups(uid int64) ([]models.Group, error) {
	gs := []models.Group{}
	_, err := Conn.Select(&gs, "SELECT g.id, g.name, g.modified_date FROM groups g, user_groups ug, users u WHERE ug.uid=u.id AND ug.gid=g.id AND u.id=?", uid)
	if err != nil {
		Logger.Println(err)
		return gs, err
	}
	for i, _ := range gs {
		_, err := Conn.Select(&gs[i].Targets, "SELECT t.id, t.email FROM targets t, group_targets gt WHERE gt.gid=? AND gt.tid=t.id", gs[i].Id)
		if err != nil {
			Logger.Println(err)
		}
	}
	return gs, nil
}

// GetGroup returns the group, if it exists, specified by the given id and user_id.
func GetGroup(id int64, uid int64) (models.Group, error) {
	g := models.Group{}
	err := Conn.SelectOne(&g, "SELECT g.id, g.name, g.modified_date FROM groups g, user_groups ug, users u WHERE ug.uid=u.id AND ug.gid=g.id AND g.id=? AND u.id=?", id, uid)
	if err != nil {
		Logger.Println(err)
		return g, err
	}
	_, err = Conn.Select(&g.Targets, "SELECT t.id, t.email FROM targets t, group_targets gt WHERE gt.gid=? AND gt.tid=t.id", g.Id)
	if err != nil {
		Logger.Println(err)
	}
	return g, nil
}

// PostGroup creates a new group in the database.
func PostGroup(g *models.Group, uid int64) error {
	// Insert into the DB
	err = Conn.Insert(g)
	if err != nil {
		Logger.Println(err)
		return err
	}
	// Now, let's add the user->user_groups->group mapping
	_, err = Conn.Exec("INSERT OR IGNORE INTO user_groups VALUES (?,?)", uid, g.Id)
	if err != nil {
		Logger.Printf("Error adding many-many mapping for group %s\n", g.Name)
	}
	for _, t := range g.Targets {
		insertTargetIntoGroup(t, g.Id)
	}
	return nil
}

// PutGroup updates the given group if found in the database.
func PutGroup(g *models.Group, uid int64) error {
	// Update all the foreign keys, and many to many relationships
	// We will only delete the group->targets entries. We keep the actual targets
	// since they are needed by the Results table
	// Get all the targets currently in the database for the group
	ts := []models.Target{}
	_, err = Conn.Select(&ts, "SELECT t.id, t.email FROM targets t, group_targets gt WHERE gt.gid=? AND gt.tid=t.id", g.Id)
	if err != nil {
		Logger.Printf("Error getting targets from group ID: %d", g.Id)
		return err
	}
	// Enumerate through, removing any entries that are no longer in the group
	// For every target in the database
	tExists := false
	for _, t := range ts {
		tExists = false
		// Is the target still in the group?
		for _, nt := range g.Targets {
			if t.Email == nt.Email {
				tExists = true
				break
			}
		}
		// If the target does not exist in the group any longer, we delete it
		if !tExists {
			_, err = Conn.Exec("DELETE FROM group_targets WHERE gid=? AND tid=?", g.Id, t.Id)
			if err != nil {
				Logger.Printf("Error deleting email %s\n", t.Email)
			}
		}
	}
	// Insert any entries that are not in the database
	// For every target in the new group
	for _, nt := range g.Targets {
		// Check and see if the target already exists in the db
		tExists = false
		for _, t := range ts {
			if t.Email == nt.Email {
				tExists = true
				break
			}
		}
		// If the target is not in the db, we add it
		if !tExists {
			insertTargetIntoGroup(nt, g.Id)
		}
	}
	return nil
}

func insertTargetIntoGroup(t models.Target, gid int64) error {
	if _, err = mail.ParseAddress(t.Email); err != nil {
		Logger.Printf("Invalid email %s\n", t.Email)
		return err
	}
	trans, err := Conn.Begin()
	if err != nil {
		Logger.Println(err)
		return err
	}
	_, err = trans.Exec("INSERT OR IGNORE INTO targets VALUES (null, ?)", t.Email)
	if err != nil {
		Logger.Printf("Error adding email: %s\n", t.Email)
		return err
	}
	// Bug: res.LastInsertId() does not work for this, so we need to select it manually (how frustrating.)
	t.Id, err = trans.SelectInt("SELECT id FROM targets WHERE email=?", t.Email)
	if err != nil {
		Logger.Printf("Error getting id for email: %s\n", t.Email)
		return err
	}
	_, err = trans.Exec("INSERT OR IGNORE INTO group_targets VALUES (?,?)", gid, t.Id)
	if err != nil {
		Logger.Printf("Error adding many-many mapping for %s\n", t.Email)
		return err
	}
	err = trans.Commit()
	if err != nil {
		Logger.Printf("Error committing db changes\n")
		return err
	}
	return nil
}

// DeleteGroup deletes a given group by group ID and user ID
func DeleteGroup(id int64) error {
	// Delete all the group_targets entries for this group
	_, err := Conn.Exec("DELETE FROM group_targets WHERE gid=?", id)
	if err != nil {
		return err
	}
	// Delete the reference to the group in the user_group table
	_, err = Conn.Exec("DELETE FROM user_groups WHERE gid=?", id)
	if err != nil {
		return err
	}
	// Delete the group itself
	_, err = Conn.Exec("DELETE FROM groups WHERE id=?", id)
	return err
}