package api

import (
	"context"
	"database/sql"
	"encoding/json"
	"errors"
	"git.misaka.ren/m1saka/dsh-web/internal/store"
	"io"
	"net/http"
	"strconv"
	"time"
)

var fetchRelease = readRelease

func (a *API) latestRelease(w http.ResponseWriter, r *http.Request) {
	u, _, err := a.user(r)
	if err != nil {
		fail(w, 401, "authentication required")
		return
	}
	if !u.Admin {
		fail(w, 403, "administrator required")
		return
	}
	if r.Method != http.MethodGet {
		fail(w, 405, "method not allowed")
		return
	}
	repository, branch, err := releaseSource()
	if err != nil {
		fail(w, 500, err.Error())
		return
	}
	info, _, err := fetchRelease(r.Context(), repository, "refs/heads/"+branch)
	if err != nil && !errors.Is(err, errReleaseIncompatible) {
		fail(w, 502, sanitizeBuildLog(err.Error()))
		return
	}
	compatible := err == nil
	reason := "trusted release supports current layout and platform"
	if !compatible {
		reason = errReleaseIncompatible.Error()
	}
	buildQueue.Lock()
	err = a.ensureBuilds()
	buildQueue.Unlock()
	if err != nil {
		fail(w, 500, "database error")
		return
	}
	var b buildRecord
	err = scanBuildSummary(a.s.DB.QueryRow("SELECT "+buildSummaryColumns+" FROM image_builds WHERE source_repository=? AND source_commit=? AND release_id=? AND platform=? ORDER BY created_at DESC,id DESC LIMIT 1", repository, info.Commit, info.ReleaseID, imagePlatform), &b)
	if err != nil && !errors.Is(err, sql.ErrNoRows) {
		fail(w, 500, "database error")
		return
	}
	result := map[string]any{"release_id": info.ReleaseID, "version": info.Version, "commit": info.Commit, "repository": repository, "branch": branch, "recipe_rev": strconv.Itoa(info.DeploymentSchema), "platforms": info.Platforms, "compatible": compatible, "reason": reason}
	if err == nil {
		result["build"] = b
	}
	writeJSON(w, result)
}

func (a *API) releaseBuild(w http.ResponseWriter, r *http.Request) {
	u, _, err := a.user(r)
	if err != nil {
		fail(w, 401, "authentication required")
		return
	}
	if !u.Admin {
		fail(w, 403, "administrator required")
		return
	}
	if r.Method != http.MethodPost {
		fail(w, 405, "method not allowed")
		return
	}
	var in struct {
		Commit string `json:"commit"`
	}
	dec := json.NewDecoder(http.MaxBytesReader(w, r.Body, 4096))
	dec.DisallowUnknownFields()
	if dec.Decode(&in) != nil || dec.Decode(new(any)) != io.EOF || !releaseCommit.MatchString(in.Commit) {
		fail(w, 400, "fixed commit required")
		return
	}
	repository, branch, err := releaseSource()
	if err != nil {
		fail(w, 500, err.Error())
		return
	}
	info, _, err := fetchRelease(r.Context(), repository, "refs/heads/"+branch)
	if err != nil {
		fail(w, 502, sanitizeBuildLog(err.Error()))
		return
	}
	if info.Commit != in.Commit {
		fail(w, 409, "release changed; check the latest release again")
		return
	}
	b, err := a.enqueueRelease(u.ID, info)
	if err != nil {
		status := 500
		if errors.Is(err, errBuildRateLimited) {
			status = 429
		}
		fail(w, status, sanitizeBuildLog(err.Error()))
		return
	}
	a.startBuildWorker()
	w.WriteHeader(http.StatusAccepted)
	writeJSON(w, b)
}

func (a *API) enqueueRelease(uid string, info releaseInfo) (buildRecord, error) {
	buildQueue.Lock()
	defer buildQueue.Unlock()
	var b buildRecord
	if err := a.ensureBuilds(); err != nil {
		return b, err
	}
	err := scanBuildSummary(a.s.DB.QueryRow("SELECT "+buildSummaryColumns+" FROM image_builds WHERE source_repository=? AND source_commit=? AND release_id=? AND platform=? AND status IN ('queued','running','validating','success')", info.Repository, info.Commit, info.ReleaseID, imagePlatform), &b)
	if err == nil {
		if b.Status == "success" {
			buildQueue.Unlock()
			ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
			matches, verifyErr := a.buildImageMatches(ctx, b.ImageID, b)
			cancel()
			buildQueue.Lock()
			if verifyErr != nil {
				return b, verifyErr
			}
			if !matches {
				if _, err = a.s.DB.Exec("UPDATE image_builds SET status='missing',error='image no longer available' WHERE id=? AND status='success'", b.ID); err != nil {
					return b, err
				}
				buildQueue.Unlock()
				b, err = a.enqueueRelease(uid, info)
				buildQueue.Lock()
				return b, err
			}
		}
		return b, nil
	}
	if !errors.Is(err, sql.ErrNoRows) {
		return b, err
	}
	var count int
	if err = a.s.DB.QueryRow("SELECT count(*) FROM image_build_requests WHERE user_id=? AND created_at>?", uid, time.Now().Add(-time.Hour).UTC().Format(time.RFC3339Nano)).Scan(&count); err != nil {
		return b, err
	}
	if count >= 3 {
		return b, errBuildRateLimited
	}
	b = buildRecord{ID: store.ID(), Version: info.Version, Status: "queued", Created: time.Now().UTC().Format(time.RFC3339Nano), RequestedBy: uid, RecipeRev: imageRecipeRev, Platform: imagePlatform, ReleaseID: info.ReleaseID, SourceRepository: info.Repository, SourceCommit: info.Commit}
	return b, a.insertBuildRequest(b, uid)
}

func (a *API) releaseBuildContext(ctx context.Context, b buildRecord) (io.Reader, error) {
	repository, _, err := releaseSource()
	if err != nil {
		return nil, err
	}
	if repository != b.SourceRepository || !releaseCommit.MatchString(b.SourceCommit) {
		return nil, errors.New("queued release source is no longer trusted")
	}
	u, err := a.s.UserByID(b.RequestedBy)
	if err != nil || !u.Admin {
		return nil, errors.New("release requester is not an administrator")
	}
	info, archive, err := fetchRelease(ctx, repository, b.SourceCommit)
	if err != nil {
		return nil, err
	}
	if info.Commit != b.SourceCommit || info.ReleaseID != b.ReleaseID || info.Version != b.Version {
		return nil, errors.New("pinned release manifest mismatch")
	}
	return archive, nil
}
func releaseLabelsMatch(im *inspectedImage, b buildRecord) bool {
	if b.ReleaseID == "" {
		return im.Config.Labels["dsh-mgr.release"] == ""
	}
	return im.Config.Labels["dsh-mgr.release"] == b.ReleaseID && im.Config.Labels["dsh-mgr.source"] == b.SourceRepository && im.Config.Labels["dsh-mgr.commit"] == b.SourceCommit
}
func (a *API) buildImageMatches(ctx context.Context, id string, b buildRecord) (bool, error) {
	matches, err := a.imageMatches(ctx, id, b.Version)
	if err != nil || !matches {
		return matches, err
	}
	im, err := a.inspectLocalImage(ctx, id)
	if err != nil || im == nil {
		return false, err
	}
	return releaseLabelsMatch(im, b), nil
}