-- IHF Phase 2 Migration: Structured Feedback and Triage
-- Introduces: annotation_threads, requirement_candidates, triage_states, reviewer_assignments
-- Extends: annotations (severity, thread_id)

-- annotation_threads must be created BEFORE altering annotations (FK reference)
CREATE TABLE annotation_threads (
    id UUID DEFAULT uuid_generate_v4() PRIMARY KEY NOT NULL,
    widget_id UUID NOT NULL REFERENCES widgets(id) ON DELETE CASCADE,
    title TEXT NOT NULL,
    description TEXT,
    created_by UUID REFERENCES users(id),
    created_at TIMESTAMP WITH TIME ZONE DEFAULT now() NOT NULL
);

-- Extend annotations with severity and thread grouping
ALTER TABLE annotations ADD COLUMN severity TEXT NOT NULL DEFAULT 'medium';
ALTER TABLE annotations ADD COLUMN thread_id UUID REFERENCES annotation_threads(id) ON DELETE SET NULL;

CREATE TABLE requirement_candidates (
    id UUID DEFAULT uuid_generate_v4() PRIMARY KEY NOT NULL,
    title TEXT NOT NULL,
    description TEXT NOT NULL,
    source_widget_id UUID NOT NULL REFERENCES widgets(id) ON DELETE RESTRICT,
    source_thread_id UUID REFERENCES annotation_threads(id) ON DELETE SET NULL,
    source_annotation_id UUID REFERENCES annotations(id) ON DELETE SET NULL,
    category TEXT NOT NULL DEFAULT 'friction',
    status TEXT NOT NULL DEFAULT 'open',
    created_by UUID REFERENCES users(id),
    created_at TIMESTAMP WITH TIME ZONE DEFAULT now() NOT NULL
);

CREATE INDEX requirement_candidates_widget_id_idx ON requirement_candidates (source_widget_id);
CREATE INDEX requirement_candidates_status_idx ON requirement_candidates (status);

CREATE TABLE triage_states (
    id UUID DEFAULT uuid_generate_v4() PRIMARY KEY NOT NULL,
    candidate_id UUID NOT NULL REFERENCES requirement_candidates(id) ON DELETE CASCADE,
    status TEXT NOT NULL,
    notes TEXT,
    changed_by UUID REFERENCES users(id),
    changed_at TIMESTAMP WITH TIME ZONE DEFAULT now() NOT NULL
);

CREATE INDEX triage_states_candidate_id_idx ON triage_states (candidate_id);

CREATE TABLE reviewer_assignments (
    id UUID DEFAULT uuid_generate_v4() PRIMARY KEY NOT NULL,
    candidate_id UUID NOT NULL REFERENCES requirement_candidates(id) ON DELETE CASCADE,
    user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    assigned_by UUID REFERENCES users(id),
    assigned_at TIMESTAMP WITH TIME ZONE DEFAULT now() NOT NULL,
    UNIQUE (candidate_id)
);