-- Datetimes are stored as 'ISO 8601' text format.
-- For example: '2025-01-07T10:41:05.697884837+00:00'.

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

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_public] 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 '',
    [quantity_value] REAL,
    [quantity_unit] TEXT NOT NULL DEFAULT '',

    [comment] TEXT NOT NULL DEFAULT '',

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

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

CREATE TABLE [RecipeScheduled] (
    [id] INTEGER PRIMARY KEY,
    [user_id] INTEGER NOT NULL,
    [recipe_id] INTEGER NOT NULL,
    [date] TEXT NOT NULL, -- In form of 'YYYY-MM-DD'.
    [servings] INTEGER, -- If NULL use [recipe].[servings].

    UNIQUE([user_id], [recipe_id], [date]),

    FOREIGN KEY([user_id]) REFERENCES [User]([id]) ON DELETE CASCADE,
    FOREIGN KEY([recipe_id]) REFERENCES [Recipe]([id]) ON DELETE CASCADE
);

CREATE INDEX [RecipeScheduled_user_id_index] ON [RecipeScheduled]([user_id]);
CREATE INDEX [RecipeScheduled_date_index] ON [RecipeScheduled]([date]);

CREATE TABLE [ShoppingEntry] (
    [id] INTEGER PRIMARY KEY,
    [user_id] INTEGER NOT NULL,
    -- The linked ingredient can be deleted or a custom entry can be manually added.
    -- In both cases [name], [quantity_value], [quantity_unit] and [Servings] are used to display
    -- the entry instead of [Ingredient] data.
    [ingredient_id] INTEGER,
    [recipe_scheduled_id] INTEGER, -- Can be null when manually added.

    [is_checked] INTEGER NOT NULL DEFAULT FALSE,

    -- The following four fields contain data only if [recipe_scheduled_id] is NULL.
    [name] TEXT NOT NULL DEFAULT '',
    [quantity_value] REAL,
    [quantity_unit] TEXT NOT NULL DEFAULT '',
    [servings] INTEGER,

    FOREIGN KEY([user_id]) REFERENCES [User]([id]) ON DELETE CASCADE,
    FOREIGN KEY([ingredient_id]) REFERENCES [Ingredient]([id]) ON DELETE SET NULL,
    FOREIGN KEY([recipe_scheduled_id]) REFERENCES [RecipeScheduled]([id]) ON DELETE SET NULL
);

CREATE INDEX [ShoppingEntry_user_id_index] ON [ShoppingEntry]([user_id]);

-- When an ingredient is deleted, its values are copied to any shopping entry
-- that referenced it.
CREATE TRIGGER [Ingredient_trigger_delete]
BEFORE DELETE
ON [Ingredient]
BEGIN
    UPDATE [ShoppingEntry]
    SET
        [name] = OLD.[name],
        [quantity_value] = OLD.[quantity_value],
        [quantity_unit] = OLD.[quantity_unit],
        [servings] = (
        	SELECT [servings]
        	FROM [Recipe]
        	INNER JOIN [Group] ON [Group].[recipe_id] = [Recipe].[id]
        	INNER JOIN [Step] ON [Step].[group_id] = [Group].[id]
        	WHERE [Step].[id] = OLD.[step_id]
    	)
    WHERE [ingredient_id] = OLD.[id];
END;

CREATE TABLE [Settings] (
    [name] TEXT NOT NULL PRIMARY KEY,

    -- Value can by anything that can be read from a text by
    -- implementing the trait 'std::str::FromStr'.
    [value] TEXT NOT NULL
) STRICT;

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