package handler

import (
	"encoding/json"
	"fmt"
	"io"
	"net/http"

	"github.com/gin-gonic/gin"
	"github.com/jackc/pgx/v5/pgxpool"
	"github.com/mattnite/cairn/internal/blob"
	"github.com/mattnite/cairn/internal/fingerprint"
	"github.com/mattnite/cairn/internal/forgejo"
	"github.com/mattnite/cairn/internal/models"
)

type IngestHandler struct {
	Pool        *pgxpool.Pool
	Store       blob.Store
	ForgejoSync *forgejo.Sync
}

type IngestRequest struct {
	Repository   string          `json:"repository"`
	Owner        string          `json:"owner"`
	CommitSHA    string          `json:"commit_sha"`
	Type         string          `json:"type"`
	CrashMessage string          `json:"crash_message,omitempty"`
	StackTrace   string          `json:"stack_trace,omitempty"`
	Tags         json.RawMessage `json:"tags,omitempty"`
	Metadata     json.RawMessage `json:"metadata,omitempty"`
}

func (h *IngestHandler) Create(c *gin.Context) {
	metaJSON := c.PostForm("meta")
	if metaJSON == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "missing 'meta' form field"})
		return
	}

	var req IngestRequest
	if err := json.Unmarshal([]byte(metaJSON), &req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid meta JSON: " + err.Error()})
		return
	}

	if req.Repository == "" || req.Owner == "" || req.CommitSHA == "" || req.Type == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "repository, owner, commit_sha, and type are required"})
		return
	}

	file, header, err := c.Request.FormFile("file")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "missing 'file' form field: " + err.Error()})
		return
	}
	defer file.Close()

	ctx := c.Request.Context()

	repo, err := models.GetOrCreateRepository(ctx, h.Pool, req.Owner, req.Repository)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	commit, err := models.GetOrCreateCommit(ctx, h.Pool, repo.ID, req.CommitSHA)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	blobKey := fmt.Sprintf("%s/%s/%s/%s", repo.Name, commit.SHA[:8], req.Type, header.Filename)

	if err := h.Store.Put(ctx, blobKey, file, header.Size); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "storing blob: " + err.Error()})
		return
	}

	var crashMsg, stackTrace *string
	if req.CrashMessage != "" {
		crashMsg = &req.CrashMessage
	}
	if req.StackTrace != "" {
		stackTrace = &req.StackTrace
	}

	artifact, err := models.CreateArtifact(ctx, h.Pool, models.CreateArtifactParams{
		RepositoryID: repo.ID,
		CommitID:     commit.ID,
		Type:         req.Type,
		BlobKey:      blobKey,
		BlobSize:     header.Size,
		CrashMessage: crashMsg,
		StackTrace:   stackTrace,
		Tags:         req.Tags,
		Metadata:     req.Metadata,
	})
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	// Run fingerprinting pipeline if we have a stack trace.
	if req.StackTrace != "" {
		if result := fingerprint.Compute(req.StackTrace); result != nil {
			sig, isNew, err := models.GetOrCreateSignature(ctx, h.Pool, repo.ID, result.Fingerprint, stackTrace)
			if err == nil {
				models.UpdateArtifactSignature(ctx, h.Pool, artifact.ID, sig.ID, result.Fingerprint)

				if isNew {
					title := req.Type + " crash in " + req.Repository
					if len(result.Frames) > 0 {
						title = req.Type + ": " + result.Frames[0].Function
					}
					group, groupErr := models.CreateCrashGroup(ctx, h.Pool, sig.ID, repo.ID, title)
					if groupErr == nil && h.ForgejoSync != nil {
						h.ForgejoSync.CreateIssueForCrashGroup(ctx, group, req.StackTrace)
					}
				}
			}
		}
	}

	c.JSON(http.StatusCreated, artifact)
}

type DownloadHandler struct {
	Pool  *pgxpool.Pool
	Store blob.Store
}

func (h *DownloadHandler) Download(c *gin.Context) {
	id := c.Param("id")

	artifact, err := models.GetArtifact(c.Request.Context(), h.Pool, id)
	if err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "artifact not found"})
		return
	}

	reader, err := h.Store.Get(c.Request.Context(), artifact.BlobKey)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "reading blob: " + err.Error()})
		return
	}
	defer reader.Close()

	c.Header("Content-Disposition", fmt.Sprintf("attachment; filename=%q", artifact.BlobKey))
	c.Header("Content-Type", "application/octet-stream")
	io.Copy(c.Writer, reader)
}