Reorganize code and clean up Makefile

misc/schema.sql

@@ -0,0 +1,29 @@
+CREATE TABLE IF NOT EXISTS Users (
+    id          INTEGER  PRIMARY KEY,
+    username    TEXT     NOT NULL UNIQUE,
+    password    TEXT     NOT NULL,
+    email       TEXT     NOT NULL UNIQUE,
+    signup_time DATETIME DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE TABLE IF NOT EXISTS Posts (
+    id                  INTEGER  PRIMARY KEY,
+    author              INTEGER  NOT NULL,
+    title               TEXT     NOT NULL,
+    is_link             BOOLEAN  NOT NULL,
+    content             TEXT     NOT NULL,
+    submit_time         DATETIME DEFAULT CURRENT_TIMESTAMP,
+    FOREIGN KEY (author) REFERENCES Users(id)
+);
+
+CREATE TABLE IF NOT EXISTS Comments (
+    id             INTEGER  PRIMARY KEY,
+    parent_post    INTEGER  NOT NULL,
+    parent_comment INTEGER,
+    author         INTEGER  NOT NULL,
+    content        TEXT     NOT NULL,
+    submit_time    DATETIME DEFAULT CURRENT_TIMESTAMP,
+    FOREIGN KEY (author)         REFERENCES Users(id),
+    FOREIGN KEY (parent_post)    REFERENCES Posts(id),
+    FOREIGN KEY (parent_comment) REFERENCES Comments(id)
+);