package main

import "strings"
import "fmt"
import "regexp"
import "database/sql"
import _ "github.com/mattn/go-sqlite3"

type irc_msg struct {
	channel	string
	msg		string
	author	string
}

type cmd struct {
	valid	bool
	add		bool
	cmd		string
	groups	[]int
	suffix	string
}

var begin_char = []byte{'<'}
var db *sql.DB
var err error

func checkErr(err error) {
	if err != nil {
		panic(err)
	}
}

func in (a byte, arr []byte) bool {
	for _, x := range arr {
		if x == a {
			return true
		}
	}
	return false
}

func unique(intSlice []int) []int {
	keys := make(map[int]bool)
	list := []int{}
	for _, entry := range intSlice {
		if _, value := keys[entry]; !value {
			keys[entry] = true
			list = append(list, entry)
		}
	}
	return list
}

// function to split advise message correctly
func filter(msg string) cmd {
	var c cmd

	if len(msg) <= 0 {
		c.valid = false
		return c
	}

	c.cmd = ""
	c.valid = false

	if strings.HasPrefix(msg, "add ") {
		c.add = true
		msg = msg[4:]
	} else {
		c.add = false
	}

	if (strings.Contains(msg, "[") && strings.Contains(msg, "]")) {
		re, _ := regexp.Compile(`\s*(\w*)\s*\[(.*)\]\s*(.*)\s*`)
		res := re.FindStringSubmatch(msg)
		if len(res) < 4 {
			return c
		}

		c.cmd = res[1]
		if c.cmd == "" {
			LOG_WARN.Printf("empty cmd\n")
			return c
		}

		// TODO: substitute group names with ids
		groups := strings.Fields(res[2])
		for _, i := range groups {
			task := fmt.Sprintf("select id from groups where name = '%s'", i)

			row, err := db.Query(task)
			if err != nil {
				LOG_WARN.Printf("no such column: %s\n", i)
				return c
			}
			group_id := 0
			if row.Next() { row.Scan(&group_id) }
			row.Close()
			if (group_id != 0) {
				c.groups = append(c.groups, group_id)
			}
		}
		c.suffix = res[3]
		c.valid = true
	} else {
		c.groups = nil
		re, _ := regexp.Compile(`\s*(\w*)\s*(.*)\s*`)
		res := re.FindStringSubmatch(msg)
		if len(res) < 3 {
			return c
		}
		c.cmd = res[1]
		if c.cmd == "" {
			return c
		}

		c.suffix = res[2]
		c.valid = true
	}
	c.cmd = strings.TrimSpace(c.cmd)
	c.suffix = strings.TrimSpace(c.suffix)

	return c
}

func getRandomEntry(c cmd) string {
	// TODO: increment counter
	// if database entry exists: set tag / group and run query
	task :=            "select distinct l.content from line l, brain b, tag t"
	if len(c.groups) > 0 {
		task = fmt.Sprintf("%s, groups g", task)
	}
	task = fmt.Sprintf("%s where l.id = b.line_id and t.id = b.tag_id", task)
	task = fmt.Sprintf("%s and t.id = %s", task, c.cmd)
	if len(c.groups) > 0 {
		task = fmt.Sprintf("%s and g.id = b.group_id and (", task)
		for i, group := range c.groups {
			task = fmt.Sprintf("%sg.id = %d", task, group)
			if i < (len(c.groups) - 1) {
				task = fmt.Sprintf("%s or ", task)
			} else {
				task = fmt.Sprintf("%s)", task)
			}
		}
	}
	return fmt.Sprintf("%s ORDER BY RANDOM() LIMIT 1", task)
}

// line:
// >befehl <[groups]> <name>
// befehl ist genau ein wort
func parsemsg(msg irc_msg, foo bot) bool {
	if len(msg.msg) <= 0 {
		return false
	}
	if !in(msg.msg[0], begin_char) {
		return false
	}
	msg.msg = msg.msg[1:]

	c := filter(msg.msg)
	if !c.valid {
		LOG_WARN.Printf("non valid input found.\n")
		return false
	}
	if c.cmd == "" {
		LOG_WARN.Printf("no command provided.\n")
		return false
	}

	sorter_row, err := db.Query(fmt.Sprintf("select id, tag_id, groups_allow, name_allow, has_groups from sorter where name = '%s'", c.cmd))
	checkErr(err)
	if sorter_row.Next() {
		var sorter_id string
		var tag_id string
		var groups_allow int
		var name_allow int
		var has_groups int
		sorter_row.Scan(&sorter_id, &tag_id, &groups_allow, &name_allow, &has_groups)

		if groups_allow != 0 {
			// warning: not allowed
			c.groups = nil // use c.groups[:0] to keep allocated space
		}
		if name_allow != 0 && !c.add {
			// warning: not allowed
			c.suffix = ""
		}

		c.cmd = tag_id

		if has_groups == 0 {
			sorter_groups_row, err := db.Query(fmt.Sprintf("select group_id from sorter_groups where sorter_id = '%s'", sorter_id))
			checkErr(err)
			if sorter_groups_row.Next() {
				var group_id int
				sorter_groups_row.Scan(&group_id)
				c.groups = append(c.groups, group_id)
			}
			sorter_groups_row.Close()
		}
		c.groups = unique(c.groups)
		sorter_row.Close()
	} else {
		LOG_WARN.Printf("no sorter entry, no translation possible\n")
		return false
	}

	if c.add {
		if (len(c.suffix) <= 0) {
			return false;
		}
		// insert into database
		statement, err := db.Prepare("insert into line (content, author) values (?,?)")
		checkErr(err)
		_, err = statement.Exec(c.suffix, msg.author)
		checkErr(err)
		defer statement.Close()

		// get ID of content...
		task := fmt.Sprintf("select l.id from line l where l.content = '%s'", c.suffix)
		row, err := db.Query(task)
		checkErr(err)
		line_id := 0
		if row.Next() { row.Scan(&line_id) }
		row.Close()
		LOG_INFO.Printf(c.cmd)
		if line_id == 0 {
			LOG_WARN.Printf("no entry for adding")
			return false
		}

		// for tag and all groups
		if len(c.groups) == 0 {
			stat, err := db.Prepare("insert into brain(line_id, tag_id) values (?,?)")
			checkErr(err)
			_, err = stat.Exec(line_id, c.cmd)
			checkErr(err)
			LOG_INFO.Printf("inserted foo! \n")
			defer stat.Close()
		} else {
			stat, err := db.Prepare("insert into brain(line_id, tag_id, group_id) values (?,?,?)")
			checkErr(err)
			for _, group := range c.groups {
				_, err = stat.Exec(line_id, c.cmd, group)
				checkErr(err)
			}
			LOG_INFO.Printf("inserted foo! \n")
			defer stat.Close()
		}
		return true
	}

	task := getRandomEntry(c)

	LOG_INFO.Printf(task)
	row, err := db.Query(task)
	checkErr(err)
	res := ""
	if row.Next() {
		row.Scan(&res)
	}
	row.Close()

	if len(res) <= 0 {
		LOG_WARN.Printf("no entry found\n")
		res = "No matching entry found :("
	} else if len(c.suffix) > 0 {
		res = fmt.Sprintf("%s... %s", c.suffix, res)
	}
	sendmsg(foo.conn, msg.channel, res)

	return true
}

/*
func test() {
	db, err = sql.Open("sqlite3", "./boddle.db")
	checkErr(err)
	var msg irc_msg
	msg.channel = "testchannel"
	msg.author = "max mustermann"

	// == invalid commands ==
	// empty cmd
	msg.msg = ">add      [test me bro hahahaha] blob"
	parsemsg(msg)
	msg.msg = ">  [test me bro hahahaha]"
	parsemsg(msg)
	msg.msg = ">[test me bro hahahaha] meow   "
	parsemsg(msg)
	msg.msg = ">add [test me bro hahahaha] meow   "
	parsemsg(msg)

	// non-existent groups
	msg.msg = ">ohai [test me bro hahahaha]"
	parsemsg(msg)

	// add command...? not implemented yet!
	msg.msg = ">add jokes blob"
	parsemsg(msg)
	msg.msg = ">add test [test me bro hahahaha] meow   "
	parsemsg(msg)

	// ok command \o/
	msg.msg = ">flirt [sweet] meow   "
	parsemsg(msg)
	msg.msg = ">jokes [flach] meow   "
	parsemsg(msg)
	msg.msg = ">hate [sweet] blobfisch   "
	parsemsg(msg)
	msg.msg = ">radschlag [science]"
	parsemsg(msg)
}
*/