-- 0001: initial schema (SPEC.md §2)

CREATE TABLE foods (
    id                  INTEGER PRIMARY KEY,
    name                TEXT NOT NULL,
    brand               TEXT,
    barcode             TEXT UNIQUE,
    source              TEXT NOT NULL CHECK (source IN ('openfoodfacts', 'manual', 'meal')),
    is_meal             INTEGER NOT NULL DEFAULT 0,
    unit_type           TEXT NOT NULL DEFAULT 'weight' CHECK (unit_type IN ('weight', 'count')),
    calories_per_unit   REAL,
    protein_per_unit    REAL,
    carbs_per_unit      REAL,
    fat_per_unit        REAL,
    fiber_per_unit      REAL,
    saturated_fat_per_unit REAL,
    sugars_per_unit     REAL,
    sodium_per_unit     REAL,
    serving_size_g      REAL,
    serving_name        TEXT,
    off_data            TEXT,
    deleted_at          TEXT,
    created_at          TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ','now')),
    updated_at          TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ','now')),
    -- Meal nutrition is derived from components, never stored (spec §2.1)
    CHECK (is_meal = 1 OR calories_per_unit IS NOT NULL)
);

CREATE TABLE meal_components (
    id       INTEGER PRIMARY KEY,
    meal_id  INTEGER NOT NULL REFERENCES foods(id),
    food_id  INTEGER NOT NULL REFERENCES foods(id),
    quantity REAL NOT NULL
);

CREATE TABLE daily_log (
    id         INTEGER PRIMARY KEY,
    date       TEXT NOT NULL,  -- client-supplied YYYY-MM-DD (spec §8.1 rule 8)
    food_id    INTEGER NOT NULL REFERENCES foods(id),
    quantity   REAL NOT NULL,
    meal_slot  TEXT CHECK (meal_slot IN ('breakfast', 'lunch', 'dinner', 'snack')),
    sort_order INTEGER NOT NULL DEFAULT 0,
    created_at TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ','now'))
);

CREATE INDEX idx_daily_log_date ON daily_log(date);

CREATE TABLE targets (
    id         INTEGER PRIMARY KEY,
    start_date TEXT NOT NULL,
    end_date   TEXT,  -- null = currently active
    calories   INTEGER NOT NULL,
    protein_g  REAL,
    carbs_g    REAL,
    fat_g      REAL
);