-- Version 1 is the initial structure.
CREATE TABLE [Version] (
    [id] INTEGER PRIMARY KEY,
    [version] INTEGER NOT NULL UNIQUE,
    [datetime] TEXT
) STRICT;

CREATE TABLE [User] (
    [id] INTEGER PRIMARY KEY,

    [email] TEXT NOT NULL,
    [name] TEXT NOT NULL DEFAULT '',
    [creation_datetime] TEXT NOT NULL,

    [default_servings] INTEGER DEFAULT 4,
    [lang] TEXT NOT NULL DEFAULT 'en',

    [password] TEXT NOT NULL, -- argon2(password_plain, salt).

    [validation_token_datetime] TEXT NOT NULL, -- Updated when the validation email is sent.
    [validation_token] TEXT, -- If not null then the user has not validated his account yet.

    [password_reset_token] TEXT, -- If not null then the user can reset its password.
    -- The time when the reset token has been created.
    -- Password can only be reset during a certain duration after this time.
    [password_reset_datetime] TEXT,

    [is_admin] INTEGER NOT NULL DEFAULT FALSE
) STRICT;

CREATE INDEX [validation_token_index] ON [User]([validation_token]);
CREATE UNIQUE INDEX [User_email_index] ON [User]([email]);

CREATE TABLE [UserLoginToken] (
    [id] INTEGER PRIMARY KEY,
    [user_id] INTEGER NOT NULL,
    [last_login_datetime] TEXT,

    -- 24 alphanumeric character token.
    -- Can be stored in a cookie to be able to authenticate without a password.
    [token] TEXT NOT NULL,

    [ip] TEXT, -- Can be ipv4 or ipv6
    [user_agent] TEXT,

    FOREIGN KEY([user_id]) REFERENCES [User]([id]) ON DELETE CASCADE
) STRICT;

CREATE INDEX [UserLoginToken_token_index] ON [UserLoginToken]([token]);

CREATE TABLE [Recipe] (
    [id] INTEGER PRIMARY KEY,
    [user_id] INTEGER, -- Can be null if a user is deleted.
    [title] TEXT NOT NULL,
     -- https://en.wikipedia.org/wiki/List_of_ISO_639_language_codes
    [lang] TEXT NOT NULL DEFAULT 'en',
    [estimated_time] INTEGER, -- in [s].
    [description] TEXT NOT NULL DEFAULT '',
    -- 0: Unknown, 1: Easy, 2: Medium, 4: Hard.
    [difficulty] INTEGER NOT NULL DEFAULT 0,
    [servings] INTEGER DEFAULT 4,
    [is_published] INTEGER NOT NULL DEFAULT FALSE,
    [creation_datetime] TEXT NOT NULL,

    FOREIGN KEY([user_id]) REFERENCES [User]([id]) ON DELETE SET NULL
) STRICT;

CREATE TRIGGER [Recipe_trigger_update_difficulty]
BEFORE UPDATE OF [difficulty]
ON [Recipe]
BEGIN
    SELECT
        CASE
            WHEN NEW.[difficulty] < 0 OR NEW.[difficulty] > 3 THEN
                RAISE (ABORT, 'Invalid [difficulty] value')
        END;
END;

CREATE TRIGGER [Recipe_trigger_insert_difficulty]
BEFORE INSERT
ON [Recipe]
BEGIN
    SELECT
        CASE
            WHEN NEW.[difficulty] < 0 OR NEW.[difficulty] > 3 THEN
                RAISE (ABORT, 'Invalid [difficulty] value')
        END;
END;

CREATE TABLE [Image] (
    [Id] INTEGER PRIMARY KEY,
    [recipe_id] INTEGER NOT NULL,
    [name] TEXT NOT NULL DEFAULT '',
    [description] TEXT NOT NULL DEFAULT '',
    [image] BLOB NOT NULL,

    FOREIGN KEY([recipe_id]) REFERENCES [Recipe]([id]) ON DELETE CASCADE
) STRICT;

CREATE TABLE [RecipeTag] (
    [id] INTEGER PRIMARY KEY,

    [recipe_id] INTEGER NOT NULL,
    [tag_id] INTEGER NOT NULL,

    UNIQUE([recipe_id], [tag_id]),

    FOREIGN KEY([recipe_id]) REFERENCES [Recipe]([id]) ON DELETE CASCADE,
    FOREIGN KEY([tag_id]) REFERENCES [Tag]([id]) ON DELETE CASCADE
) STRICT;

CREATE TABLE [Tag] (
    [id] INTEGER PRIMARY KEY,
    [name] TEXT NOT NULL
     -- https://en.wikipedia.org/wiki/List_of_ISO_639_language_codes
) STRICT;

CREATE UNIQUE INDEX [Tag_name_lang_index] ON [Tag]([name]);

CREATE TABLE [Group] (
    [id] INTEGER PRIMARY KEY,

    [order] INTEGER NOT NULL DEFAULT 0,
    [recipe_id] INTEGER NOT NULL,

    [name] TEXT NOT NULL DEFAULT '',
    [comment] TEXT NOT NULL DEFAULT '',

    FOREIGN KEY([recipe_id]) REFERENCES [Recipe]([id]) ON DELETE CASCADE
) STRICT;

CREATE INDEX [Group_order_index] ON [Group]([order]);

CREATE TABLE [Step] (
    [id] INTEGER PRIMARY KEY,

    [order] INTEGER NOT NULL DEFAULT 0,
    [group_id] INTEGER NOT NULL,

    [action] TEXT NOT NULL DEFAULT '',

    FOREIGN KEY(group_id) REFERENCES [Group](id) ON DELETE CASCADE
) STRICT;

CREATE INDEX [Step_order_index] ON [Group]([order]);

CREATE TABLE [Ingredient] (
    [id] INTEGER PRIMARY KEY,

    [order] INTEGER NOT NULL DEFAULT 0,
    [step_id] INTEGER NOT NULL,

    [name] TEXT NOT NULL DEFAULT '',
    [comment] TEXT NOT NULL DEFAULT '',
    [quantity_value] REAL,
    [quantity_unit] TEXT NOT NULL DEFAULT '',

    FOREIGN KEY([step_id]) REFERENCES [Step]([id]) ON DELETE CASCADE
) STRICT;

CREATE INDEX [Ingredient_order_index] ON [Ingredient]([order]);

-- Table not strict because [value] can story any type of data.
CREATE TABLE [Settings] (
    [name] TEXT NOT NULL PRIMARY KEY,
    [value] TEXT NOT NULL
);

INSERT INTO [Settings] ([name], [value]) VALUES ('new_user_registration_enabled', TRUE);