package db

import (
	"context"
	"database/sql"
	"fmt"
	"os"
	"path/filepath"

	_ "modernc.org/sqlite"
)

type Store struct {
	DB *sql.DB
}

func Open(path string) (*Store, error) {
	if path != ":memory:" {
		if err := os.MkdirAll(filepath.Dir(path), 0750); err != nil {
			return nil, fmt.Errorf("create database directory: %w", err)
		}
	}
	db, err := sql.Open("sqlite", path)
	if err != nil {
		return nil, fmt.Errorf("open sqlite: %w", err)
	}
	if _, err := db.Exec("PRAGMA foreign_keys = ON"); err != nil {
		_ = db.Close()
		return nil, fmt.Errorf("enable foreign keys: %w", err)
	}
	if path == ":memory:" {
		db.SetMaxOpenConns(1)
	}
	return &Store{DB: db}, nil
}

func (s *Store) Close() error {
	if s == nil || s.DB == nil {
		return nil
	}
	return s.DB.Close()
}

func (s *Store) Ping(ctx context.Context) error {
	return s.DB.PingContext(ctx)
}

func (s *Store) Migrate(ctx context.Context) error {
	_, err := s.DB.ExecContext(ctx, schemaSQL)
	if err != nil {
		return fmt.Errorf("migrate sqlite: %w", err)
	}
	return nil
}

const schemaSQL = `
CREATE TABLE IF NOT EXISTS mail_messages (
	id INTEGER PRIMARY KEY AUTOINCREMENT,
	account_id TEXT NOT NULL,
	pop3_uid TEXT NOT NULL,
	message_id_header TEXT,
	in_reply_to TEXT,
	references_header TEXT,
	subject TEXT,
	sender_name TEXT,
	sender_email TEXT,
	to_json TEXT NOT NULL DEFAULT '[]',
	cc_json TEXT NOT NULL DEFAULT '[]',
	date_header TEXT,
	sent_at TEXT,
	received_at TEXT NOT NULL,
	body_text TEXT,
	body_html TEXT,
	raw_eml_path TEXT,
	has_attachment INTEGER NOT NULL DEFAULT 0,
	local_read INTEGER NOT NULL DEFAULT 0,
	local_processed INTEGER NOT NULL DEFAULT 0,
	local_archived INTEGER NOT NULL DEFAULT 0,
	local_deleted INTEGER NOT NULL DEFAULT 0,
	local_replied INTEGER NOT NULL DEFAULT 0,
	created_at TEXT NOT NULL,
	updated_at TEXT NOT NULL,
	UNIQUE(account_id, pop3_uid)
);

CREATE INDEX IF NOT EXISTS idx_mail_messages_account_uid ON mail_messages(account_id, pop3_uid);
CREATE INDEX IF NOT EXISTS idx_mail_messages_message_id ON mail_messages(message_id_header);
CREATE INDEX IF NOT EXISTS idx_mail_messages_sender ON mail_messages(sender_email);
CREATE INDEX IF NOT EXISTS idx_mail_messages_sent_at ON mail_messages(sent_at);
CREATE INDEX IF NOT EXISTS idx_mail_messages_status ON mail_messages(local_read, local_processed, local_archived, local_deleted, local_replied);

CREATE TABLE IF NOT EXISTS attachments (
	id INTEGER PRIMARY KEY AUTOINCREMENT,
	message_id INTEGER NOT NULL,
	file_name TEXT NOT NULL,
	content_type TEXT,
	content_id TEXT,
	size_bytes INTEGER NOT NULL DEFAULT 0,
	storage_path TEXT NOT NULL,
	created_at TEXT NOT NULL,
	FOREIGN KEY(message_id) REFERENCES mail_messages(id) ON DELETE CASCADE
);

CREATE INDEX IF NOT EXISTS idx_attachments_message ON attachments(message_id);

CREATE TABLE IF NOT EXISTS labels (
	id INTEGER PRIMARY KEY AUTOINCREMENT,
	name TEXT NOT NULL UNIQUE,
	color TEXT,
	created_at TEXT NOT NULL,
	updated_at TEXT NOT NULL
);

CREATE TABLE IF NOT EXISTS message_labels (
	message_id INTEGER NOT NULL,
	label_id INTEGER NOT NULL,
	created_at TEXT NOT NULL,
	PRIMARY KEY(message_id, label_id),
	FOREIGN KEY(message_id) REFERENCES mail_messages(id) ON DELETE CASCADE,
	FOREIGN KEY(label_id) REFERENCES labels(id) ON DELETE CASCADE
);

CREATE INDEX IF NOT EXISTS idx_message_labels_label ON message_labels(label_id);

CREATE TABLE IF NOT EXISTS drafts (
	id INTEGER PRIMARY KEY AUTOINCREMENT,
	to_json TEXT NOT NULL DEFAULT '[]',
	cc_json TEXT NOT NULL DEFAULT '[]',
	bcc_json TEXT NOT NULL DEFAULT '[]',
	subject TEXT,
	body TEXT,
	reply_to_email_id INTEGER,
	status TEXT NOT NULL DEFAULT 'draft',
	last_error TEXT,
	sent_message_id INTEGER,
	created_at TEXT NOT NULL,
	updated_at TEXT NOT NULL,
	FOREIGN KEY(reply_to_email_id) REFERENCES mail_messages(id) ON DELETE SET NULL
);

CREATE INDEX IF NOT EXISTS idx_drafts_status ON drafts(status);

CREATE TABLE IF NOT EXISTS sent_messages (
	id INTEGER PRIMARY KEY AUTOINCREMENT,
	draft_id INTEGER,
	to_json TEXT NOT NULL DEFAULT '[]',
	cc_json TEXT NOT NULL DEFAULT '[]',
	bcc_json TEXT NOT NULL DEFAULT '[]',
	subject TEXT,
	body TEXT,
	message_id_header TEXT,
	in_reply_to TEXT,
	references_header TEXT,
	smtp_from TEXT,
	status TEXT NOT NULL,
	error_message TEXT,
	sent_at TEXT,
	created_at TEXT NOT NULL,
	FOREIGN KEY(draft_id) REFERENCES drafts(id) ON DELETE SET NULL
);

CREATE INDEX IF NOT EXISTS idx_sent_messages_draft ON sent_messages(draft_id);
CREATE INDEX IF NOT EXISTS idx_sent_messages_status ON sent_messages(status);
`