-- ============================================================================
-- PROPOSAL LIFECYCLE PLUGIN
-- Draft → Review → Active → Archived with versioning, diffs, and forks
-- ============================================================================

-- ============================================================================
-- PROPOSAL LIFECYCLE STATUS
-- Extended status tracking beyond basic states
-- ============================================================================

CREATE TYPE proposal_lifecycle_status AS ENUM (
    'draft',           -- Initial creation, not yet submitted
    'submitted',       -- Submitted for review
    'review',          -- Under community/moderator review
    'revision',        -- Sent back for revision
    'active',          -- Open for discussion/voting
    'voting',          -- In voting phase
    'passed',          -- Voting passed, pending implementation
    'rejected',        -- Voting rejected
    'implemented',     -- Successfully implemented
    'archived',        -- Archived (completed or abandoned)
    'withdrawn'        -- Withdrawn by author
);

-- ============================================================================
-- PROPOSAL VERSIONS
-- Complete version history with semantic diffing
-- ============================================================================

CREATE TABLE proposal_versions (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    proposal_id UUID NOT NULL REFERENCES proposals(id) ON DELETE CASCADE,
    version_number INT NOT NULL,
    
    -- Version content (full snapshot)
    title VARCHAR(500) NOT NULL,
    content TEXT NOT NULL,
    summary TEXT,
    
    -- Metadata
    created_by UUID NOT NULL REFERENCES users(id),
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    
    -- Change tracking
    change_type VARCHAR(50) NOT NULL DEFAULT 'edit', -- create, edit, amendment, merge
    change_summary TEXT,
    
    -- Diff from previous version
    diff_from_previous JSONB, -- Structured diff data
    
    -- Status at this version
    status_at_version proposal_lifecycle_status NOT NULL,
    
    -- Review info
    reviewed_by UUID REFERENCES users(id),
    reviewed_at TIMESTAMPTZ,
    review_notes TEXT,
    
    UNIQUE(proposal_id, version_number)
);

CREATE INDEX idx_proposal_versions_proposal ON proposal_versions(proposal_id);
CREATE INDEX idx_proposal_versions_created ON proposal_versions(proposal_id, created_at);
CREATE INDEX idx_proposal_versions_author ON proposal_versions(created_by);

COMMENT ON TABLE proposal_versions IS 'Complete version history for proposals';

-- ============================================================================
-- PROPOSAL LIFECYCLE TRACKING
-- Extended lifecycle metadata
-- ============================================================================

CREATE TABLE proposal_lifecycle (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    proposal_id UUID NOT NULL REFERENCES proposals(id) ON DELETE CASCADE UNIQUE,
    
    -- Current state
    current_status proposal_lifecycle_status NOT NULL DEFAULT 'draft',
    current_version INT NOT NULL DEFAULT 1,
    
    -- Timing
    submitted_at TIMESTAMPTZ,
    review_started_at TIMESTAMPTZ,
    activated_at TIMESTAMPTZ,
    voting_started_at TIMESTAMPTZ,
    voting_ended_at TIMESTAMPTZ,
    resolved_at TIMESTAMPTZ,
    archived_at TIMESTAMPTZ,
    
    -- Review tracking
    review_count INT NOT NULL DEFAULT 0,
    revision_count INT NOT NULL DEFAULT 0,
    
    -- Fork tracking
    forked_from_id UUID REFERENCES proposals(id),
    fork_count INT NOT NULL DEFAULT 0,
    
    -- Amendment tracking
    amendment_count INT NOT NULL DEFAULT 0,
    merged_amendments JSONB DEFAULT '[]',
    
    -- Metadata
    lifecycle_config JSONB NOT NULL DEFAULT '{}',
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE INDEX idx_proposal_lifecycle_proposal ON proposal_lifecycle(proposal_id);
CREATE INDEX idx_proposal_lifecycle_status ON proposal_lifecycle(current_status);
CREATE INDEX idx_proposal_lifecycle_forked ON proposal_lifecycle(forked_from_id);

COMMENT ON TABLE proposal_lifecycle IS 'Extended lifecycle tracking for proposals';

-- ============================================================================
-- PROPOSAL STATUS TRANSITIONS
-- Audit log of all status changes
-- ============================================================================

CREATE TABLE proposal_status_transitions (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    proposal_id UUID NOT NULL REFERENCES proposals(id) ON DELETE CASCADE,
    
    -- Transition
    from_status proposal_lifecycle_status,
    to_status proposal_lifecycle_status NOT NULL,
    
    -- Actor
    triggered_by UUID REFERENCES users(id),
    trigger_type VARCHAR(50) NOT NULL, -- manual, auto, vote, workflow
    
    -- Context
    reason TEXT,
    metadata JSONB NOT NULL DEFAULT '{}',
    
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE INDEX idx_status_transitions_proposal ON proposal_status_transitions(proposal_id);
CREATE INDEX idx_status_transitions_time ON proposal_status_transitions(created_at);

COMMENT ON TABLE proposal_status_transitions IS 'Audit trail of proposal status changes';

-- ============================================================================
-- PROPOSAL FORKS
-- Track proposal forks (very FLOSS-friendly)
-- ============================================================================

CREATE TABLE proposal_forks (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    
    -- Source
    source_proposal_id UUID NOT NULL REFERENCES proposals(id),
    source_version_number INT NOT NULL,
    
    -- Fork
    fork_proposal_id UUID NOT NULL REFERENCES proposals(id) UNIQUE,
    
    -- Metadata
    forked_by UUID NOT NULL REFERENCES users(id),
    forked_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    fork_reason TEXT,
    
    -- Relationship status
    is_competing BOOLEAN NOT NULL DEFAULT FALSE, -- Competing alternative
    is_merged BOOLEAN NOT NULL DEFAULT FALSE, -- Merged back
    merged_at TIMESTAMPTZ
);

CREATE INDEX idx_proposal_forks_source ON proposal_forks(source_proposal_id);
CREATE INDEX idx_proposal_forks_fork ON proposal_forks(fork_proposal_id);

COMMENT ON TABLE proposal_forks IS 'Proposal fork relationships';

-- ============================================================================
-- PROPOSAL AMENDMENTS
-- Suggested changes from community
-- ============================================================================

CREATE TYPE amendment_status AS ENUM (
    'proposed',    -- Suggested by community member
    'under_review', -- Being reviewed by author/moderators
    'accepted',    -- Accepted and incorporated
    'rejected',    -- Rejected by author
    'withdrawn',   -- Withdrawn by proposer
    'superseded'   -- Superseded by another amendment
);

CREATE TABLE proposal_amendments (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    proposal_id UUID NOT NULL REFERENCES proposals(id) ON DELETE CASCADE,
    target_version INT NOT NULL,
    
    -- Amendment content
    title VARCHAR(200) NOT NULL,
    description TEXT NOT NULL,
    suggested_changes JSONB NOT NULL, -- Structured change suggestions
    
    -- Author
    proposed_by UUID NOT NULL REFERENCES users(id),
    proposed_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    
    -- Status
    status amendment_status NOT NULL DEFAULT 'proposed',
    
    -- Review
    reviewed_by UUID REFERENCES users(id),
    reviewed_at TIMESTAMPTZ,
    review_response TEXT,
    
    -- If accepted
    incorporated_in_version INT,
    
    -- Voting (if community votes on amendments)
    vote_required BOOLEAN NOT NULL DEFAULT FALSE,
    vote_result JSONB,
    
    -- Support tracking
    support_count INT NOT NULL DEFAULT 0,
    oppose_count INT NOT NULL DEFAULT 0
);

CREATE INDEX idx_amendments_proposal ON proposal_amendments(proposal_id);
CREATE INDEX idx_amendments_status ON proposal_amendments(status);
CREATE INDEX idx_amendments_author ON proposal_amendments(proposed_by);

COMMENT ON TABLE proposal_amendments IS 'Community-suggested amendments to proposals';

-- ============================================================================
-- AMENDMENT SUPPORT
-- Track support/opposition for amendments
-- ============================================================================

CREATE TABLE amendment_support (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    amendment_id UUID NOT NULL REFERENCES proposal_amendments(id) ON DELETE CASCADE,
    user_id UUID NOT NULL REFERENCES users(id),
    support_type VARCHAR(20) NOT NULL, -- support, oppose, neutral
    comment TEXT,
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    UNIQUE(amendment_id, user_id)
);

CREATE INDEX idx_amendment_support_amendment ON amendment_support(amendment_id);

-- ============================================================================
-- HELPER FUNCTIONS
-- ============================================================================

-- Create a new version of a proposal
CREATE OR REPLACE FUNCTION create_proposal_version(
    p_proposal_id UUID,
    p_title VARCHAR(500),
    p_content TEXT,
    p_summary TEXT,
    p_created_by UUID,
    p_change_type VARCHAR(50),
    p_change_summary TEXT
) RETURNS INT AS $$
DECLARE
    v_version_number INT;
    v_previous_content TEXT;
    v_current_status proposal_lifecycle_status;
BEGIN
    -- Get current version number and content
    SELECT current_version INTO v_version_number
    FROM proposal_lifecycle
    WHERE proposal_id = p_proposal_id;
    
    IF v_version_number IS NULL THEN
        v_version_number := 0;
    END IF;
    
    v_version_number := v_version_number + 1;
    
    -- Get previous content for diff
    SELECT content INTO v_previous_content
    FROM proposal_versions
    WHERE proposal_id = p_proposal_id
    ORDER BY version_number DESC
    LIMIT 1;
    
    -- Get current status
    SELECT COALESCE(current_status, 'draft') INTO v_current_status
    FROM proposal_lifecycle
    WHERE proposal_id = p_proposal_id;
    
    -- Create version
    INSERT INTO proposal_versions (
        proposal_id, version_number, title, content, summary,
        created_by, change_type, change_summary, status_at_version,
        diff_from_previous
    ) VALUES (
        p_proposal_id, v_version_number, p_title, p_content, p_summary,
        p_created_by, p_change_type, p_change_summary, v_current_status,
        CASE WHEN v_previous_content IS NOT NULL THEN
            jsonb_build_object(
                'type', 'text_diff',
                'previous_length', LENGTH(v_previous_content),
                'new_length', LENGTH(p_content),
                'changed', v_previous_content != p_content
            )
        ELSE NULL END
    );
    
    -- Update lifecycle
    INSERT INTO proposal_lifecycle (proposal_id, current_version)
    VALUES (p_proposal_id, v_version_number)
    ON CONFLICT (proposal_id) DO UPDATE SET
        current_version = v_version_number,
        revision_count = proposal_lifecycle.revision_count + 1,
        updated_at = NOW();
    
    RETURN v_version_number;
END;
$$ LANGUAGE plpgsql;

-- Transition proposal status
CREATE OR REPLACE FUNCTION transition_proposal_status(
    p_proposal_id UUID,
    p_new_status proposal_lifecycle_status,
    p_triggered_by UUID,
    p_trigger_type VARCHAR(50),
    p_reason TEXT DEFAULT NULL
) RETURNS BOOLEAN AS $$
DECLARE
    v_current_status proposal_lifecycle_status;
    v_valid_transition BOOLEAN := FALSE;
BEGIN
    -- Get current status
    SELECT current_status INTO v_current_status
    FROM proposal_lifecycle
    WHERE proposal_id = p_proposal_id;
    
    -- Validate transition (simplified - can be expanded)
    v_valid_transition := CASE v_current_status
        WHEN 'draft' THEN p_new_status IN ('submitted', 'withdrawn')
        WHEN 'submitted' THEN p_new_status IN ('review', 'revision', 'withdrawn')
        WHEN 'review' THEN p_new_status IN ('revision', 'active', 'rejected')
        WHEN 'revision' THEN p_new_status IN ('submitted', 'withdrawn')
        WHEN 'active' THEN p_new_status IN ('voting', 'archived', 'withdrawn')
        WHEN 'voting' THEN p_new_status IN ('passed', 'rejected')
        WHEN 'passed' THEN p_new_status IN ('implemented', 'archived')
        WHEN 'rejected' THEN p_new_status IN ('revision', 'archived')
        WHEN 'implemented' THEN p_new_status IN ('archived')
        ELSE FALSE
    END;
    
    IF NOT v_valid_transition THEN
        RETURN FALSE;
    END IF;
    
    -- Log transition
    INSERT INTO proposal_status_transitions (
        proposal_id, from_status, to_status,
        triggered_by, trigger_type, reason
    ) VALUES (
        p_proposal_id, v_current_status, p_new_status,
        p_triggered_by, p_trigger_type, p_reason
    );
    
    -- Update lifecycle
    UPDATE proposal_lifecycle
    SET current_status = p_new_status,
        updated_at = NOW(),
        submitted_at = CASE WHEN p_new_status = 'submitted' THEN NOW() ELSE submitted_at END,
        review_started_at = CASE WHEN p_new_status = 'review' THEN NOW() ELSE review_started_at END,
        activated_at = CASE WHEN p_new_status = 'active' THEN NOW() ELSE activated_at END,
        voting_started_at = CASE WHEN p_new_status = 'voting' THEN NOW() ELSE voting_started_at END,
        voting_ended_at = CASE WHEN p_new_status IN ('passed', 'rejected') THEN NOW() ELSE voting_ended_at END,
        resolved_at = CASE WHEN p_new_status IN ('implemented', 'rejected', 'withdrawn') THEN NOW() ELSE resolved_at END,
        archived_at = CASE WHEN p_new_status = 'archived' THEN NOW() ELSE archived_at END
    WHERE proposal_id = p_proposal_id;
    
    RETURN TRUE;
END;
$$ LANGUAGE plpgsql;

-- Fork a proposal
CREATE OR REPLACE FUNCTION fork_proposal(
    p_source_proposal_id UUID,
    p_forked_by UUID,
    p_fork_reason TEXT,
    p_community_id UUID
) RETURNS UUID AS $$
DECLARE
    v_source_version INT;
    v_source_title VARCHAR(500);
    v_source_content TEXT;
    v_new_proposal_id UUID;
BEGIN
    -- Get source proposal latest version
    SELECT pv.version_number, pv.title, pv.content
    INTO v_source_version, v_source_title, v_source_content
    FROM proposal_versions pv
    JOIN proposal_lifecycle pl ON pl.proposal_id = pv.proposal_id
    WHERE pv.proposal_id = p_source_proposal_id
      AND pv.version_number = pl.current_version;
    
    -- Create new proposal
    INSERT INTO proposals (community_id, author_id, title, content, status)
    VALUES (p_community_id, p_forked_by, 
            '[Fork] ' || v_source_title, 
            v_source_content,
            'draft')
    RETURNING id INTO v_new_proposal_id;
    
    -- Initialize lifecycle
    INSERT INTO proposal_lifecycle (proposal_id, current_status, forked_from_id)
    VALUES (v_new_proposal_id, 'draft', p_source_proposal_id);
    
    -- Create initial version
    PERFORM create_proposal_version(
        v_new_proposal_id,
        '[Fork] ' || v_source_title,
        v_source_content,
        'Forked from proposal ' || p_source_proposal_id,
        p_forked_by,
        'create',
        'Fork created'
    );
    
    -- Record fork relationship
    INSERT INTO proposal_forks (
        source_proposal_id, source_version_number,
        fork_proposal_id, forked_by, fork_reason
    ) VALUES (
        p_source_proposal_id, v_source_version,
        v_new_proposal_id, p_forked_by, p_fork_reason
    );
    
    -- Update source fork count
    UPDATE proposal_lifecycle
    SET fork_count = fork_count + 1
    WHERE proposal_id = p_source_proposal_id;
    
    RETURN v_new_proposal_id;
END;
$$ LANGUAGE plpgsql;

-- ============================================================================
-- VIEWS
-- ============================================================================

CREATE OR REPLACE VIEW proposal_lifecycle_summary AS
SELECT 
    p.id AS proposal_id,
    p.title,
    p.community_id,
    c.name AS community_name,
    pl.current_status::text AS status,
    pl.current_version,
    pl.submitted_at,
    pl.activated_at,
    pl.voting_started_at,
    pl.resolved_at,
    pl.revision_count,
    pl.fork_count,
    pl.amendment_count,
    pl.forked_from_id,
    u.username AS author_username,
    p.created_at
FROM proposals p
JOIN proposal_lifecycle pl ON pl.proposal_id = p.id
JOIN communities c ON c.id = p.community_id
JOIN users u ON u.id = p.author_id
ORDER BY p.created_at DESC;

CREATE OR REPLACE VIEW proposal_version_history AS
SELECT 
    pv.proposal_id,
    pv.version_number,
    pv.title,
    pv.change_type,
    pv.change_summary,
    pv.status_at_version::text AS status,
    u.username AS author_username,
    pv.created_at,
    pv.reviewed_by IS NOT NULL AS was_reviewed
FROM proposal_versions pv
JOIN users u ON u.id = pv.created_by
ORDER BY pv.proposal_id, pv.version_number DESC;

-- ============================================================================
-- TRIGGERS
-- ============================================================================

-- Auto-initialize lifecycle when proposal is created
CREATE OR REPLACE FUNCTION auto_init_proposal_lifecycle()
RETURNS TRIGGER AS $$
BEGIN
    INSERT INTO proposal_lifecycle (proposal_id, current_status)
    VALUES (NEW.id, 'draft')
    ON CONFLICT DO NOTHING;
    
    -- Create initial version
    INSERT INTO proposal_versions (
        proposal_id, version_number, title, content,
        created_by, change_type, status_at_version
    ) VALUES (
        NEW.id, 1, NEW.title, NEW.description,
        NEW.author_id, 'create', 'draft'
    ) ON CONFLICT DO NOTHING;
    
    RETURN NEW;
END;
$$ LANGUAGE plpgsql;

CREATE TRIGGER trg_auto_init_proposal_lifecycle
AFTER INSERT ON proposals
FOR EACH ROW
EXECUTE FUNCTION auto_init_proposal_lifecycle();

-- ============================================================================
-- PLUGIN REGISTRATION
-- ============================================================================

INSERT INTO plugins (name, description, version, is_core, is_active, settings_schema)
VALUES (
    'proposal_lifecycle',
    'Complete proposal lifecycle management with versioning, semantic diffs, amendments, and FLOSS-style forking. Tracks Draft → Review → Active → Archived transitions.',
    '1.0.0',
    true,
    true,
    jsonb_build_object(
        'type', 'object',
        'properties', jsonb_build_object(
            'require_review', jsonb_build_object(
                'type', 'boolean',
                'title', 'Require Review',
                'description', 'Require moderator review before proposals become active',
                'default', true
            ),
            'allow_forks', jsonb_build_object(
                'type', 'boolean',
                'title', 'Allow Forks',
                'description', 'Allow community members to fork proposals',
                'default', true
            ),
            'allow_amendments', jsonb_build_object(
                'type', 'boolean',
                'title', 'Allow Amendments',
                'description', 'Allow community members to suggest amendments',
                'default', true
            ),
            'amendment_vote_threshold', jsonb_build_object(
                'type', 'integer',
                'title', 'Amendment Vote Threshold',
                'description', 'Support count required before amendment is considered',
                'default', 5,
                'minimum', 1
            ),
            'max_revisions', jsonb_build_object(
                'type', 'integer',
                'title', 'Max Revisions',
                'description', 'Maximum times a proposal can be sent back for revision',
                'default', 3,
                'minimum', 1,
                'maximum', 10
            )
        )
    )
) ON CONFLICT (name) DO UPDATE SET
    version = EXCLUDED.version,
    description = EXCLUDED.description;