import { serve } from "bun";
import packages from "../database/database/packages.json";
import programs from "../database/database/programs.json";

// Pre-sort data for indexDetails endpoints
const packagesLatestRepos = [...packages].sort(
  (a, b) => new Date(b.created_at).getTime() - new Date(a.created_at).getTime()
);
const packagesMostUsed = [...packages].sort(
  (a, b) => (b.usage_count || 0) - (a.usage_count || 0)
);
const programsLatestRepos = [...programs].sort(
  (a, b) => new Date(b.created_at).getTime() - new Date(a.created_at).getTime()
);
const programsMostUsed = [...programs].sort(
  (a, b) => (b.usage_count || 0) - (a.usage_count || 0)
);

serve({
  port: 7860,
  fetch(req) {
    const url = new URL(req.url);
    const pathname = url.pathname;
    const q = url.searchParams.get("q")?.trim().toLowerCase();
    const filter = url.searchParams.get("filter")?.trim().toLowerCase();

    const corsHeaders = {
      "Content-Type": "application/json",
      "Access-Control-Allow-Origin": "*",
    };

    // CORS preflight handling
    if (req.method === "OPTIONS") {
      return new Response(null, {
        status: 204,
        headers: {
          "Access-Control-Allow-Origin": "*",
          "Access-Control-Allow-Methods": "GET, POST, OPTIONS",
          "Access-Control-Allow-Headers": "Content-Type",
        },
      });
    }

    if (pathname === "/api/searchPackages") {
      const results = packages.filter(
        ({ name, full_name, description, topics }) => {
          if (
            filter &&
            !topics?.some((t: string) => t.toLowerCase() === filter)
          )
            return false;
          if (!q) return true;
          return [name, full_name, description, ...(topics || [])].some(
            (field: string) => field?.toLowerCase().includes(q),
          );
        },
      );

      return new Response(JSON.stringify(results.slice(0, 25)), {
        status: 200,
        headers: corsHeaders,
      });
    }

    if (pathname === "/api/searchPrograms") {
      const results = programs.filter(({ full_name, description, topics }) => {
        if (filter && !topics?.some((t: string) => t.toLowerCase() === filter))
          return false;
        if (!q) return true;
        return [full_name, description, ...(topics || [])].some(
          (field: string) => field?.toLowerCase().includes(q),
        );
      });

      return new Response(JSON.stringify(results.slice(0, 25)), {
        status: 200,
        headers: corsHeaders,
      });
    }

    if (pathname === "/api/infiniteScrollPackages") {
      const pageNumberParam = url.searchParams.get("pageNumber");
      const pageNumber = parseInt(pageNumberParam || "0", 10);

      if (isNaN(pageNumber) || pageNumber < 0) {
        return new Response(JSON.stringify({ error: "Invalid page number" }), {
          status: 400,
          headers: corsHeaders,
        });
      }

      const lowerLimit = pageNumber * 10;
      const scrollResults = packages.slice(lowerLimit, lowerLimit + 10);

      return new Response(JSON.stringify(scrollResults), {
        status: 200,
        headers: corsHeaders,
      });
    }

    if (pathname === "/api/infiniteScrollPrograms") {
      const pageNumberParam = url.searchParams.get("pageNumber");
      const pageNumber = parseInt(pageNumberParam || "0", 10);

      if (isNaN(pageNumber) || pageNumber < 0) {
        return new Response(JSON.stringify({ error: "Invalid page number" }), {
          status: 400,
          headers: corsHeaders,
        });
      }

      const lowerLimit = pageNumber * 10;
      const scrollResults = programs.slice(lowerLimit, lowerLimit + 10);

      return new Response(JSON.stringify(scrollResults), {
        status: 200,
        headers: corsHeaders,
      });
    }

    // New: Get program by owner and repo name
    const programMatch = pathname.match(/^\/api\/programs\/([^\/]+)\/([^\/]+)$/);
    if (programMatch) {
      const [, owner, repo] = programMatch;
      const program = programs.find(
        (p) =>
          p.owner?.toLowerCase() === owner.toLowerCase() &&
          p.name?.toLowerCase() === repo.toLowerCase()
      );
      if (program) {
        return new Response(JSON.stringify(program), {
          status: 200,
          headers: corsHeaders,
        });
      }
      return new Response(JSON.stringify({ error: "Program not found" }), {
        status: 404,
        headers: corsHeaders,
      });
    }

    // New: Get package by owner and repo name
    const packageMatch = pathname.match(/^\/api\/packages\/([^\/]+)\/([^\/]+)$/);
    if (packageMatch) {
      const [, owner, repo] = packageMatch;
      const pkg = packages.find(
        (p) =>
          p.owner?.toLowerCase() === owner.toLowerCase() &&
          p.name?.toLowerCase() === repo.toLowerCase()
      );
      if (pkg) {
        return new Response(JSON.stringify(pkg), {
          status: 200,
          headers: corsHeaders,
        });
      }
      return new Response(JSON.stringify({ error: "Package not found" }), {
        status: 404,
        headers: corsHeaders,
      });
    }

    // Helper to parse range string like "0..100"
    function parseRange(rangeStr: string | null, max: number) {
      if (!rangeStr) return [0, Math.min(10, max)];
      const match = rangeStr.match(/^(\d+)\.\.(\d+)$/);
      if (!match) return [0, Math.min(10, max)];
      const start = Math.max(0, parseInt(match[1], 10));
      const end = Math.min(max, parseInt(match[2], 10));
      return [start, end];
    }

    // /api/indexDetailsPackages
    if (pathname === "/api/indexDetailsPackages") {
      const section = url.searchParams.get("section");
      const rangeStr = url.searchParams.get("range");
      let data = packages;

      if (section === "latestRepos") {
        data = packagesLatestRepos;
      } else if (section === "mostUsed") {
        data = packagesMostUsed;
      }

      const [start, end] = parseRange(rangeStr, data.length);
      return new Response(JSON.stringify(data.slice(start, end)), {
        status: 200,
        headers: corsHeaders,
      });
    }

    // /api/indexDetailsPrograms
    if (pathname === "/api/indexDetailsPrograms") {
      const section = url.searchParams.get("section");
      const rangeStr = url.searchParams.get("range");
      let data = programs;

      if (section === "latestRepos") {
        data = programsLatestRepos;
      } else if (section === "mostUsed") {
        data = programsMostUsed;
      }

      const [start, end] = parseRange(rangeStr, data.length);
      return new Response(JSON.stringify(data.slice(start, end)), {
        status: 200,
        headers: corsHeaders,
      });
    }

    return new Response("Not Found", {
      status: 404,
      headers: { "Access-Control-Allow-Origin": "*" },
    });
  },
});