package store

import "database/sql"

// References to all available prepared statements.
var (
	votingInsert *sql.Stmt
	votingSelect *sql.Stmt
	voteEligible *sql.Stmt
	voteInsert   *sql.Stmt
	voteSelect   *sql.Stmt
)

// initCreateTables takes an sql connection and creates all tables if they
// don't yet exist.
func initCreateTables(db *sql.DB) {
	var err error
	createTables := `
  CREATE TABLE IF NOT EXISTS voting (
    id TEXT PRIMARY KEY,
    referendum TEXT NOT NULL,
    created DATETIME WITHOUT TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
    deadline DATETIME WITHOUT TIME ZONE NOT NULL,
    quorum TEXT NOT NULL DEFAULT 'SIMPLE',
    threshold TEXT NOT NULL DEFAULT 'SIMPLE',
    electors TEXT,
    anonymous BOOL NOT NULL DEFAULT false
  );

  CREATE TABLE IF NOT EXISTS vote (
    id BLOB PRIMARY KEY,
    voting TEXT NOT NULL,
    elector TEXT NOT NULL,
    choice TEXT NOT NULL,
    timestamp DATETIME WITHOUT TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY(voting) REFERENCES voting(id)
  );

  CREATE INDEX IF NOT EXISTS vote_voting ON vote ( voting );
  `

	if _, err = db.Exec(createTables); err != nil {
		panic(err)
	}
}

// initStmts takes an initialized sql connection and initializes all prepared
// statements.
func initStmts(db *sql.DB) {
	initStmtVotingInsert(db)
	initStmtVotingSelect(db)

	initStmtVoteEligible(db)
	initStmtVoteInsert(db)
	initStmtVoteSelect(db)
}

func initStmtVotingInsert(db *sql.DB) {
	var err error
	if votingInsert, err = db.Prepare(`
    INSERT INTO voting (
      id,
      referendum,
      deadline,
      quorum,
      threshold,
      electors,
      anonymous
    ) VALUES (?, ?, ?, ?, ?, ?, ?);
  `); err != nil {
		panic(err)
	}
}

func initStmtVotingSelect(db *sql.DB) {
	var err error
	if votingSelect, err = db.Prepare(`
    SELECT
      referendum,
      deadline,
      quorum,
      threshold,
      electors,
      anonymous
    FROM voting
    WHERE id = ?;
  `); err != nil {
		panic(err)
	}
}

func initStmtVoteEligible(db *sql.DB) {
	var err error
	if voteEligible, err = db.Prepare(`
    SELECT
      id,
      referendum,
      created,
      deadline,
      quorum,
      threshold
    FROM voting
    WHERE
      id = ? 
      AND deadline > datetime('now')
      AND (
        electors IS NULL 
        OR ',' || electors || ',' LIKE '%,' || ? || ',%'
      )
    LIMIT 1;
  `); err != nil {
		panic(err)
	}
}

func initStmtVoteInsert(db *sql.DB) {
	var err error
	if voteInsert, err = db.Prepare(`
    INSERT INTO vote (
      id, voting, elector, choice
    ) VALUES (
      ?, ?, ?, ?
    );
  `); err != nil {
		panic(err)
	}
}

func initStmtVoteSelect(db *sql.DB) {
	var err error
	if voteSelect, err = db.Prepare(`
    SELECT
      id,
      elector,
      choice,
      timestamp
    FROM vote
    WHERE voting = ?;
  `); err != nil {
		panic(err)
	}
}