BEGIN;

CREATE EXTENSION postgis;

CREATE SCHEMA wamos;
SET search_path TO public, wamos;

CREATE FUNCTION update_date_info() RETURNS trigger
    LANGUAGE plpgsql
    AS $$
    BEGIN
        NEW.date_info = CURRENT_TIMESTAMP;
        RETURN NEW;
    END;
$$;

-- Composite type: UN/LOCODE, fairway section, object reference, hectometre.
-- See RIS-Index Encoding Guide
CREATE TYPE isrs AS (
       country_code char(2), -- ISO 3166 country code
       -- could be validated against countries table.
       locode char(3), -- without the country code:
       -- http://www.unece.org/cefact/locode/welcome.html
       fairway_section char(5),
       object_reference char(5),
       hectometre int -- should be constrained to five digits
);

CREATE TYPE isrsrange AS RANGE (
       subtype = isrs
       );

-- Eventually obsolete.
-- See https://roundup-intern.intevation.de/wamos/issue5
-- CREATE TABLE rwdrs (
--        stretch isrsrange PRIMARY KEY,
--        -- https://www.postgresql.org/docs/10/static/sql-createindex.html:
--        -- Only B-tree supports UNIQUE indexes, but we need the GIST index
--        -- below anyhow.
--        -- Is it a good idea to build B-tree indexes on relatively large
--        -- composites of string values or should we use inter PKs?
--        -- => In case the index is used and cache space becomes a limiting
--        -- factor, this might be an issue.
--        rwdr double precision NOT NULL,
--        EXCLUDE USING GIST (stretch WITH &&)
--        );

CREATE TABLE wamos.countries (
       country_code char(2) PRIMARY KEY -- ISO 3166 country code
       -- A smallint PK would require even less disk space i.e. on the FK side.
       -- This might be an issue in case cache space becomes a limiting
       -- factor when there are many FKs pointing here.
       );

--
-- General river information
--
CREATE TABLE wamos.waterway_area (
       dummy_attrib varchar,
       "..." varchar
       -- TODO: add real waterway area attributes (DRC 2.1.3)
       );

CREATE TABLE wamos.reference_water_levels (
       reference_water_level varchar(20) PRIMARY KEY
       );

CREATE TABLE wamos.gauges (
       location isrs PRIMARY KEY,
       dummy_attrib varchar,
       "..." varchar
       -- TODO: add real gauge attributes (DRC 2.1.4)
       );

CREATE TABLE wamos.gauges_reference_water_levels (
       gauge_id isrs NOT NULL REFERENCES gauges,
       reference_water_level varchar(20)
           NOT NULL REFERENCES reference_water_levels,
       PRIMARY KEY (gauge_id, reference_water_level),
       value int NOT NULL
       );

CREATE TABLE wamos.gauge_measurements (
       fk_gauge_id isrs NOT NULL REFERENCES gauges,
       -- XXX: Is country_code really relevant for WAMOS or just NtS?
       -- country_code char(2) NOT NULL REFERENCES countries,
       -- TODO: add relations to stuff provided as enumerations
       dummy_attrib varchar,
       "..." varchar
       -- TODO: add real gauge measurement attributes (DRC 2.1.5)
       );

CREATE TABLE wamos.waterway_axis (
       dummy_attrib varchar,
       "..." varchar
       -- TODO: add real waterway area attributes (DRC 2.1.3)
       );

CREATE TABLE wamos.distance_marks (
       location_code isrs PRIMARY KEY,
       -- TODO: add relations to stuff provided as enumerations
       dummy_attrib varchar,
       "..." varchar
       -- TODO: add real distance mark attributes (DRC 2.1.7)
       );

CREATE TABLE sections_stretches (
       id varchar PRIMARY KEY,
       is_section boolean NOT NULL, -- maps 'function' from interface
       stretch isrsrange,
       dummy_attrib varchar,
       "..." varchar
       -- TODO: add real section/stretch attributes (DRC 2.2.1)
       );

--
-- Bottlenecks
--
CREATE TABLE wamos.riverbed_materials (
       material varchar PRIMARY KEY
       -- XXX: Should this table contain choices from DRC 2.2.3 or
       -- from IENC Encoding Guide M.4.3, attribute NATSUR?
       );

CREATE TABLE wamos.survey_types (
       survey_type varchar PRIMARY KEY
       );

CREATE TABLE wamos.coverage_types (
       coverage_type varchar PRIMARY KEY
       );

CREATE TABLE wamos.limiting_factors (
       limiting_factor varchar PRIMARY KEY
       );

CREATE TABLE wamos.depth_references (
       depth_reference varchar(4) PRIMARY KEY
       -- See col. AB and AI RIS-Index Encoding Guide
       -- XXX: We need a way to distinguish between geodetic (eg. col. AP
       -- RIS-Index) and other references (e.g. col. AB and AI):
       -- _ multi-column FK with a boolean column (geodetic/non-geodetic;
       --   i.e. absolut/not absolut) and DEFAULTs and CHECKs at the FK side.
       -- _ Do not mixup things with different meanings in one table at all
       --   (which would mean a model differing a bit from RIS-Index ideas)
       );

-- XXX: Nullability differs between DRC (attributes marked "O") and WSDL
-- (minOccurs=0; nillable seems to be set arbitrarily as even bottleneck_id and
-- fk_g_fid (both mandatory, i.e. marked "M" in DRC) have nillable="true" in WSDL)
CREATE TABLE wamos.bottlenecks (
       bottleneck_id varchar PRIMARY KEY,
       fk_g_fid isrs NOT NULL REFERENCES gauges,
       -- XXX: DRC references "ch. 3.1.1", which does not exist in document.
       objnam varchar,
       nobjnm varchar,
       stretch isrsrange NOT NULL,
       area geometry(POLYGON, 3146) NOT NULL,
       rb char(2) NOT NULL REFERENCES countries, -- from rb_lb in interface
       lb char(2) NOT NULL REFERENCES countries, -- from rb_lb in interface
       responsible_country char(2) NOT NULL REFERENCES countries,
       revisiting_time smallint NOT NULL,
       limiting varchar NOT NULL REFERENCES limiting_factors,
       surtyp varchar NOT NULL REFERENCES survey_types,
       -- XXX: Also an attribut of sounding result?
       coverage varchar REFERENCES coverage_types,
       -- XXX: Also an attribut of sounding result?
       -- CHECK allowed combinations of surtyp and coverage or
       -- different model approach?
       depth_reference char(3) NOT NULL REFERENCES depth_references,
       -- XXX: Also an attribut of sounding result?
       date_info timestamp with time zone NOT NULL DEFAULT CURRENT_TIMESTAMP,
       source_organization varchar NOT NULL,
       -- additional_data xml -- Currently not relevant for WAMOS
       staging_done boolean NOT NULL DEFAULT false
       );
CREATE TRIGGER bottleneck_date_info BEFORE UPDATE ON bottlenecks
       FOR EACH ROW EXECUTE PROCEDURE update_date_info();

CREATE TABLE wamos.bottlenecks_riverbed_materials (
       bottleneck_id varchar REFERENCES bottlenecks,
       riverbed varchar REFERENCES riverbed_materials,
       -- XXX: should be 'natsur' according to IENC Encoding Guide M.4.3
       PRIMARY KEY (bottleneck_id, riverbed)
       );

CREATE TABLE wamos.sounding_results (
       bottleneck_id varchar NOT NULL REFERENCES bottlenecks,
       date_info date NOT NULL,
       PRIMARY KEY (bottleneck_id, date_info),
       area geometry(POLYGON, 3146) NOT NULL,
       surtyp varchar NOT NULL REFERENCES survey_types,
       coverage varchar REFERENCES coverage_types,
       depth_reference char(3) NOT NULL REFERENCES depth_references,
       sounding_data raster NOT NULL,
       staging_done boolean NOT NULL DEFAULT false
       );

--
-- Fairway availability
--
CREATE TABLE wamos.spot_marks (
       mark_name varchar PRIMARY KEY
       -- Use smallint because of fairway availability provided on daily basis?
       );

CREATE TABLE wamos.levels_of_service (
       level_of_service smallint PRIMARY KEY
       );

CREATE TABLE wamos.measure_types (
       measure_type varchar PRIMARY KEY
       );

CREATE TABLE wamos.fairway_availability (
       id int PRIMARY KEY GENERATED BY DEFAULT AS IDENTITY,
       position varchar REFERENCES spot_marks,
       bottleneck_id varchar NOT NULL REFERENCES bottlenecks,
       surdat date NOT NULL,
       UNIQUE (bottleneck_id, surdat),
       -- additional_data xml -- Currently not relevant for WAMOS
       critical boolean,
       date_info timestamp with time zone NOT NULL DEFAULT CURRENT_TIMESTAMP,
       source_organization varchar NOT NULL
       );
CREATE TRIGGER fairway_availability_date_info
       BEFORE UPDATE ON fairway_availability
       FOR EACH ROW EXECUTE PROCEDURE update_date_info();

CREATE TABLE wamos.fa_reference_values (
       fairway_availability_id int NOT NULL REFERENCES fairway_availability,
       level_of_service smallint NOT NULL REFERENCES levels_of_service,
       PRIMARY KEY (fairway_availability_id, level_of_service),
       fairway_depth smallint,
       fairway_width smallint,
       fairway_radius int,
       CHECK(COALESCE(fairway_depth, fairway_width, fairway_radius) IS NOT NULL),
       shallowest_spot geometry(POINT, 3146)
       );

CREATE TABLE wamos.bottleneck_pdfs (
       fairway_availability_id int NOT NULL REFERENCES fairway_availability,
       profile_pdf_filename varchar NOT NULL, -- redundant to last part of URL
       profile_pdf_url varchar NOT NULL, -- prohibit insecure URLs somehow?
       PRIMARY KEY (fairway_availability_id, profile_pdf_url),
       pdf_generation_date timestamp with time zone NOT NULL,
       source_organization varchar NOT NULL
       );

CREATE TABLE wamos.effective_fairway_availability (
       fairway_availability_id int NOT NULL REFERENCES fairway_availability,
       measure_date timestamp with time zone NOT NULL,
       level_of_service smallint NOT NULL REFERENCES levels_of_service,
       PRIMARY KEY (fairway_availability_id, measure_date, level_of_service),
       available_depth_value smallint,
       available_width_value smallint,
       water_level_value smallint,
       CHECK(COALESCE(available_depth_value, available_width_value,
           water_level_value) IS NOT NULL),
       measure_type varchar NOT NULL REFERENCES measure_types,
       source_organization varchar NOT NULL,
       forecast_generation_time timestamp with time zone,
       CHECK(measure_type <> 'forecasted'
             OR forecast_generation_time IS NOT NULL),
       value_lifetime timestamp with time zone,
       CHECK(measure_type = 'minimum guaranteed' OR value_lifetime IS NOT NULL)
       );

COMMIT;